纳米材料在根尖周炎中应用的未来展望

Introduction Chronic apical periodontitis is a typical inflammatory disease of the oral cavity, the pathology is characterized by an inflammatory reaction with bone defects in the periapical area. Chinese medicine is our traditional medicine, Carbon Dots (CDs) are a new type of nanomaterials. The purpose of this study was to prepare Yam Carbon Dots (YAM-CDs) to investigate the mechanism of action of YAM-CDs on bone differentiation in vivo and in vitro. Methods We characterized YAM-CDs using transmission electron microscopy (TEM), Fourier Transform Infrared Spectrometer (FTIR), X-Ray Diffraction (XRD) and photoluminescence (PL). CCK-8 assay, Real-time qPCR, and Western Blot were conducted using bone marrow mesenchymal stem cells (BMSCs) to verify that YAM-CDs promote osteoblast differentiation. In addition, we investigated the role of YAM-CDs in promoting bone formation in an inflammatory setting in an in vivo mouse model of cranial defects. Results The results of TEM and PL showed that the YAM-CDs mostly consisted of the components C1s, O1s, and N1s. Additionally the average sizes of YAM-CDs were 2–6 nm. The quantum yield was 4.44%, with good fluorescence stability and biosafety. Real-time qPCR and Western blot analysis showed that YAM-CDs promoted osteoblast differentiation under an inflammatory environment by regulating expression of histone demethylase 4B (KDM4B). In vivo, results showed that YAM-CDs effectively repaired cranial bone defects in a mouse model and reduced the expression of inflammatory factors under the action of lipopolysaccharides (LPS). Conclusion YAM-CDs promoted the proliferation and differentiation of osteoblasts by regulating the expression of KDM4B to repair cranial bone defects in mice under an LPS-induced inflammatory milieu, which will provide a new idea for the treatment of clinical periapical inflammation and other bone defect diseases.

Enterococcus faecalis ( E. faecalis ) biofilm-associated persistent endodontic infections (PEIs) are one of the most common tooth lesions, causing chronic periapical periodontitis, root resorption, and even tooth loss. Clinical root canal disinfectants have the risk of damaging soft tissues (e.g., mucosa and tongue) and teeth in the oral cavity, unsatisfactory to the therapy of PEIs. Nanomaterials with remarkable antibacterial properties and good biocompatibility have been developed as a promising strategy for removing pathogenic bacteria and related biofilm. Herein, carbon dots (CDs) derived from fucoidan (FD) are prepared through a one-pot hydrothermal method for the treatment of PEIs. The prepared FDCDs (7.15 nm) with sulfate groups and fluorescence property are well dispersed and stable in water. Further, it is found that in vitro FDCDs display excellent inhibiting effects on E. faecalis and its biofilm by inducing the formation of intracellular and extracellular reactive oxygen species and altering bacterial permeability. Importantly, the FDCDs penetrated the root canals and dentinal tubules, removing located E. faecalis biofilm. Moreover, the cellular assays show that the developed FDCDs have satisfactory cytocompatibility and promote macrophage recruitment. Thus, the developed FDCDs hold great potential for the management of PEIs. Graphical Abstract

Enterococcus Faecalis (E. faecalis) infection is a leading cause of refractory apical periodontitis (RAP), where persistent inflammation and bone resorption contribute to poor healing outcomes. Traditional therapies often fail to effectively eradicate E. faecalis. In this study, we develop a novel nanozyme, LysPd138@ZIF-8, by synthesizing a ZIF-8 framework and encapsulated a bacteriophage lysin specific to E. faecalis. This nanozyme exhibits excellent biocompatibility, targeted antibacterial activity, and sustained drug release. Antibacterial assays demonstrate superior efficacy in eliminating E. faecalis, including biofilm-related bacteria. Alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining confirm that LysPd138@ZIF-8 promotes osteogenesis, while Quantitative PCR (qPCR) analysis show upregulation of osteogenesis-related genes in osteoblasts. Ex vivo tooth experiments further validate its antibacterial efficacy against E. faecalis within complex dental structures. In a mouse model of apical periodontitis, treatment with LysPd138@ZIF-8 effectively clear E. faecalis from the pulp, reduce bone resorption as observed via CT imaging, and significantly inhibit periapical inflammation as evidenced by histological staining. In conclusion, LysPd138@ZIF-8 represents a promising therapeutic strategy for refractory apical periodontitis, combining potent antibacterial efficacy against E. faecalis with osteogenic properties for enhanced clinical management of this challenging condition.

Background Application of pulp regenerative cell therapy for mature teeth with periapical lesions is a critical clinical challenge. The bacterial infection in inaccessible location within the root canal system and in the periapical lesions could cause resistance and impediment, leading to limitations in successful therapy. Thus, the aim of this study was to examine the effect of residual bacteria on the outcome of pulp regeneration in mature teeth with apical periodontitis in dogs. Methods Periapical lesions were induced in 32 root canals of 4 dogs in two different models in severities, model A and model B. Model A (moderate infection): the canal exposed to the oral cavity for 2 weeks and then closed for 2 weeks. Model B (severe infection): the canal exposed to the oral cavity for 2 months and then closed for 5 months. All root canals were irrigated with 6% sodium hypochlorite, and 3% EDTA and further with 0.015% levofloxacin-containing nanobubbles, which was also used as an intracanal medicament. The aseptic conditions were examined by bacterial anaerobic culture and/or PCR analyses. The root canal treatment was repeated several times, and allogeneic dental pulp stem cells were transplanted into the root canals. The radiographic evaluation of periapical lesions was performed by cone-beam computed tomography before the first treatment, just after cell transplantation, and after 2 months and 6 months in both model A, model B, respectively. The animals were then sacrificed and the jaw blocks were harvested for histological and histobacteriological evaluations of pulp regeneration and periapical tissue healing. Furthermore, the DiI-labelled DPSCs were transplanted into the root canals after complete disinfection (n = 4) or without root canal treatment (n = 4) in the apical periodontitis model (model A) in one dog, and cell localization was compared 72 h after transplantation. Results In 8 out of 12 canals from model A, and 10 out of 15 canals from model B, pulp regeneration with good vascularization, innervation, and a significant reduction in the radiolucent area of the periapical lesions were observed. However, in the other 4 canals and 5 canals from model A and model B, respectively, no pulp tissue was regenerated, and inflammation in the periapical tissue, and external resorption or healed external resorption were detected. The presence of residual bacteria in the periapical tissues and severe inflammation were significantly associated with inhibition of regenerated pulp tissue in these 9 unsuccessful canals (P < 0.05, each) (OR = 0.075, each) analyzed by multiple logistic regression analysis. For cellular kinetics, transplanted cells remained in the disinfected root canals, while they were not detected in the infected root canals, suggesting their migration through the apical foramen under the influence of inflammation. Conclusions A true pulp-dentin complex was regenerated in the root canal by the pulp regenerative therapy in mature teeth with apical lesions. The successful pulp regeneration was negatively associated both with residual bacteria and inflammation in the periapical tissue. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-023-03628-6.

Background/purpose Enterococcus faecalis (E. faecalis) is considered a predominant pathogen for persistent periapical infections. Antisense walR (ASwalR) RNA was reported to inhibit the biofilm formation and sensitized E. faecalis to calcium hydroxide medication. The aims of this study were to investigate whether the graphene oxide (GO) nanosheets could be used to enhance antibacterial activity of ASwalR RNA for E. faecalis in periapical periodontitis. Materials and methods We developed a graphene-based plasmid transformation system by loading antisense walR plasmid with GO-polyethylenimine (PEI) complexes (GO-PEI-ASwalR). The particle size distributions and zeta-potential of the GO-PEI-ASwalR were evaluated. Then, ASwalR plasmids were labeled with gene encoding enhanced green fluorescent protein (ASwalR-eGFP). The transformation efficiencies and the bacterial viability of E. faecalis were evaluated by confocal laser scanning microscopy. Quantitative real-time PCR assays were used to investigate the expressions of E. faecalis virulent genes after transformed by GO-PEI-ASwalR. Also, the antibacterial properties of the GO-PEI-ASwalR were validated in the rat periapical periodontitis model. Results We showed that GO-PEI could efficiently deliver the ASwalR plasmid into E. faecalis cell. GO-PEI-ASwalR significantly reduced virulent-associated gene expressions. Furthermore, GO-PEI-ASwalR suppressed biofilm aggregation and improved bactericidal effects using infected canal models in vitro. In four-weeks periapical infective rat models, the GO-PEI-ASwalR strains remarkably reduced the periapical lesion size. Conclusion Transformation efficiency and antibacterial prosperity of ASwalR can be marked improved by GO-PEI based delivery system for E. faecalis infections.

Aim Cyclophilin A (CypA)/CD147 signaling plays critical roles in the regulation of inflammation and bone metabolism. This study aimed to investigate the participation of CypA/CD147 in mice periapical lesions progression and its relationship with bone resorption. Methodology Periapical lesions were induced by pulp exposure in the first lower molars of 40 C57BL/6J mice. The mice were sacrificed on days 0, 7, 14, 21, 28, 35, 42, and 49. Mandibles were harvested for X-ray imaging, microcomputed tomography scanning, histologic observation, immunohistochemistry, enzyme histochemistry, and double immunofluorescence analysis. Western blot was employed to further detect the related molecular signaling pathways in LPS-stimulated RAW 264.7 cells treated with CypA inhibitor. Results The volume and area of the periapical lesions increased from day 0 to day 35 and remained comparably stable until day 49. Immunohistochemistry demonstrated that the CypA expression levels also increased from day 0 to day 35 and decreased until day 49, similar to CD147 expression (R2 = 0.4423, P < 0.05), osteoclast number (R2 = 0.5101, P < 0.01), and the expression of osteoclastogenesis-related matrix metalloproteinase 9 (MMP-9) (R2 = 0.4715, P < 0.05). Serial sections further confirmed the colocalization of CypA and CD147 on osteoclasts with immunohistochemistry. And the distribution of CypA-positive or CD147-positive cells was positively correlated with the dynamics of MMP-9-positive cells by using immunofluorescence analysis. Furthermore, CD147 and MMP-9 expression in RAW 264.7 cells were both downregulated with CypA inhibitor treatment (P < 0.05). Conclusions The present study reveals the positive correlation of CypA/CD147 signaling and osteoclast-related MMP-9 expression in mice inflammatory periapical lesions progression. Therefore, intervention of CypA/CD147 signaling could probably provide a potential therapeutic target for attenuating inflammatory bone resorption.

Background and aims The ultimate goal of endodontic therapy is to prevent periradicular disease or to promote the healing of the periradicular lesions. The use of nontoxic, biocompatible, and bioactive materials designed for root canal obturation is preferred due to their increased potential to induce healing and bone regeneration, thereby restoring the functionality of the tooth and the adjacent tissues. The aim of this study was to analyze the biomineralization ability of an experimental endodontic sealer based on synthesized nanoparticles of calcium silicates. Methods Six plastic moulds were filled with the freshly prepared experimental endodontic sealer and kept for 3 days at room temperature in a moist environment. After hardening, four samples were subsequently immersed in simulated body fluid (SBF) and introduced in incubator at 37°C and 100% relative humidity; two of them were kept for 7 days and the other two for 14 days. Two samples were not immersed in SBF and were used for comparison. The biomineralization potential was assessed by XRPD, SEM and EDS analysis. Results Following immersion in SBF, XRPD analysis identified apatite crystals for experimental material both after 7 and 14 days. SEM images displayed the specific microstructure for bioceramic materials alongside with the presence of apatite crystals on their surface. EDS identified the presence of phosphorus and calcium elements, underlining the biomineralization potential of the experimental material. Conclusion Interaction between experimental material and SBF succeeded in inducing precipitation of apatite on its surface, evidenced by XRDP, SEM and EDS analysis.

No abstract available

Regenerative endodontics is a developing field involving the restoration of tooth structure and re-vitality of necrotic pulp. One of the most critical clinical considerations for regenerative endodontic procedures is the disinfection of the root canal system, since infection interferes with regeneration, repair, and stem cell activity. In this study, we aimed to provide the synthesis of injectable biopolymeric tissue scaffolds that can be used in routine clinical and regenerative endodontic treatment procedures using Gelatin methacryloyl (GelMA), and to test the antimicrobial efficacy of Gelatin methacryloyl/Silver nanoparticles (GelMA/AgNP), Gelatin methacryloyl/Hyaluronic acid (GelMA/HYA), and Gelatin methacryloyl/hydroxyapatite (GelMA/HA) composite hydrogels against microorganisms that are often encountered in stubborn infections in endodontic microbiology. Injectable biocomposite hydrogels exhibiting effective antimicrobial activity and non-cytotoxic behavior were successfully synthesized. This is also promising for clinical applications of regenerative endodontic procedures with hydrogels, which are proposed based on the collected data. The GelMA hydrogel loaded with hyaluronic acid showed the highest efficacy against Enterococcus faecalis, one of the stubborn bacteria in the root canal. The GelMA hydrogel loaded with hydroxyapatite also showed a significant effect against Candida albicans, which is another bacteria responsible for stubborn infections in the root canal.

No abstract available

Antibiotic medications have been found to hinder the success of regenerative endodontic treatment due to the rapid degradation of the drug, and the acidic nature of ciprofloxacin (CIP) can be harmful to stem cells of the apical papilla (SCAPs), the cells responsible for regeneration. In this study, a nanocarrier system was used for controlled drug release for longer drug activity and less cytotoxicity to the cells. CIP was loaded in poly (ethylene glycol) methyl ether- block -poly (lactide- co -glycolide) (PEG–PLGA) nanoparticles (NPs) with an ion-pairing agent. The NPs demonstrated a monodispersed spherical morphology with a mean diameter of 120.7 ± 0.43 nm. The encapsulation efficiency of the CIP-loaded PEG–PLGA NPs was 63.26 ± 9.24%, and the loading content was 7.75 ± 1.13%. Sustained CIP release was achieved over 168 h and confirmed with theoretical kinetic models. Enhanced NP bactericidal activity was observed against Enterococcus faecalis . Additionally, CIP-loaded PEG–PLGA NPs had a low cytotoxic effect on SCAPs. These results suggest the use of a nanocarrier system to prolong the antibiotic activity, provide a sterile environment, and prevent reinfection by the bacteria remaining in the root canal during regenerative endodontic treatment.

No abstract available

Mineral trioxide aggregate (MTA) is a calcium silicate-based endodontic biomaterial widely used for its biocompatibility, sealing ability, and osteoconductive potential; however, further enhancement of its bone regenerative capacity without compromising structural stability remains of interest. Strontium apatite (SrAp), a bioactive calcium phosphate phase structurally analogous to bone mineral, may promote osteogenic activity and bone regeneration. In this study, standardized cylindrical defects (2.5 mm diameter, 4 mm depth) were created in the right tibial metaphysis of systemically healthy rats and allocated to four groups: empty defect (control), pure MTA, 25SrAp–MTA, and 50SrAp–MTA. SrAp nanoparticles were synthesized hydrothermally and incorporated into the MTA matrix at predefined weight fractions. Materials were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). After 8 weeks, tibial specimens were harvested and processed for H&E histology; fibrous tissue formation, new bone formation, and osteoblastic cell presence were semi-quantitatively scored. XRD and FT-IR confirmed that SrAp incorporation preserved the fundamental Ca-silicate phase architecture and hydration chemistry of MTA, indicating chemical and crystallographic stability. SEM–EDX demonstrated progressive microstructural densification with increasing SrAp content, with reduced intergranular porosity and homogeneous SrAp distribution. Histologically, both SrAp–MTA groups exhibited significantly higher new bone formation and osteoblastic activity than untreated controls (p < 0.05), while fibrotic tissue formation did not differ significantly among groups. Although SrAp–MTA composites did not show statistically significant superiority over pure MTA after multiple-comparison adjustment, they demonstrated consistent osteogenic trends relative to empty defects. Overall, SrAp reinforcement yields a chemically compatible and structurally stable MTA-based composite that supports an enhanced osteogenic response in vivo without increasing fibrosis, suggesting potential utility in endodontic surgery and bone defect repair; longer-term and quantitative analyses are warranted to optimize SrAp content and confirm long-term performance.

Hydrogel-based regenerative endodontic procedures (REPs) are considered to be very promising therapeutic strategies to reconstruct the dental pulp (DP) tissue in devitalized human teeth. However, the success of the regeneration process is limited by residual bacteria that may persist in the endodontic space after the disinfection step and contaminate the biomaterial. The aim of this work was to develop an innovative fibrin hydrogel incorporating clindamycin (CLIN)-loaded Poly (d,l) Lactic Acid (PLA) nanoparticles (NPs) to provide the hydrogel with antibacterial properties. CLIN-PLA-NPs were synthesized by a surfactant-free nanoprecipitation method and their microphysical properties were assessed by dynamic light scattering, electrophoretic mobility and scanning electron microscopy. Their antimicrobial efficacy was evaluated on Enteroccocus fæcalis by the determination of the minimal inhibitory concentration (MIC) and the minimal biofilm inhibition and eradication concentrations (MBIC and MBEC). Antibacterial properties of the nanocomposite hydrogel were verified by agar diffusion assays. NP distribution into the hydrogel and release from it were evaluated using fluorescent PLA-NPs. NP cytotoxicity was assessed on DP mesenchymal stem cells (DP-MSCs) incorporated into the hydrogel. Type I collagen synthesis was investigated after 7 days of culture by immunohistochemistry. We found that CLIN-PLA-NPs displayed a drug loading of 10 ± 2 μg per mg of PLA polymer and an entrapment efficiency of 43 ± 7%. Antibiotic loading did not affect NP size, polydispersity index and zeta potential. The MIC for Enterococcus fæcalis was 32 μg mL-1. MBIC50 and MBEC50 were 4 and 16 μg mL-1, respectively. CLIN-PLA-NPs appeared homogenously distributed throughout the hydrogel. CLIN-PLA-NP-loaded hydrogels clearly inhibited E. faecalis growth. DP-MSC viability and type I collagen synthesis within the fibrin hydrogel were not affected by CLIN-PLA-NPs. In conclusion, CLIN-PLA-NP incorporation into the fibrin hydrogel gave the latter antibacterial and antibiofilm properties without affecting cell viability and function. This formulation could help establish an aseptic environment supporting DP reconstruction and, accordingly, might be a valuable tool for REPs.

AIM An appropriate scaffold material is crucial for the success of tissue-engineered regenerative endodontic therapies. In this study, a porcine-derived decellularized dental pulp matrix hydrogel (pDDPM-G) was prepared and employed as the primary scaffold for in situ regeneration of the pulp-dentine complex in beagle dogs. METHODS In the orthotopic pulp regeneration model, pDDPM-G was either directly injected into the root canals of canine teeth (with or without blood induction) or used as a carrier for transplantation of dental pulp stem cells (DPSCs). Collagen type I (COL I) injection (with or without blood induction) and revascularization therapy (blood induction alone) served as controls. Computed tomography images were acquired before and after surgery. Histological and immunofluorescence analyses were conducted for in vivo characterization at 14 and 90 days post-surgery, respectively. RESULTS The experimental results showed that the application of pDDPM-G was critical to all three regenerative endodontic procedures, whether combined with DPSC transplantation, used with blood induction (BI), or applied alone for cell homing. Integration of pDDPM-G reduced the extent of intracanal calcification compared with conventional revascularization therapy (BI) alone. Furthermore, expression of all representative proteins, including odontoblast-like (DSPP and DMP1), angiogenic (CD31 and KDR) and neurogenic (MAP2 and TUJ1) markers, was much higher in all pDDPM-G-containing groups than in the BI+COL I, COL I and BI groups. CONCLUSION This study demonstrated the significance of pDDPM-G in functional endodontic regeneration using an orthotopic canine model. It was found that the use of pDDPM-G was not only beneficial for root development but also facilitated pulp-like tissue morphogenesis, dentinogenesis, angiogenesis and neurogenesis, thereby reconstructing hierarchically distributed functional pulp-dentine complexes.

Combined injectable cell-laden microspheres and angiogenesis approaches are promising for functional vascularized endodontic regeneration. However, advanced microsphere designs and production techniques that benefit practical applications are rarely developed. Herein, gelatin methacryloyl (GelMA)-alginate core-shell microcapsules were fabricated to co-encapsulate human dental pulp stem cells (hDPSCs) and human umbilical vein endothelial cells (HUVECs) based on a coaxial electrostatic microdroplet technique. This technique enables high-throughput production, convenient collection, and minimal material waste. The average diameter of core-shell microcapsules was ∼359 μm, and that of GelMA cores was ∼278 μm. There were higher proliferation rates for hDPSCs and HUVECs co-encapsulated in the GelMA cores than for hDPSCs or HUVECs monoculture group. HUVECs assembled to and form 3D capillary-like networks in co-culture microcapsules. Moreover, HUVECs promoted the osteo/odontogenic differentiation of hDPSCs in microcapsules. After 14 days of cultivation, prevascularized microtissues formed in microcapsules that contained abundant deposited extracellular matrix (ECM); no microcapsule aggregation occurred. In vivo studies confirmed that better microvessel formation and pulp-like tissue regeneration occurred in the co-culture group than in hDPSCs group. Thus, an effective platform for prevascularization microtissue preparation was proposed and showed great promise in endodontic regeneration and tissue engineering applications. STATEMENT OF SIGNIFICANCE: : Cell-laden microspheres combined with the proangiogenesis approach are promising in endodontic regeneration. We proposed GelMA-alginate core-shell microcapsules generated via the coaxial electrostatic microdroplet (CEM) method, which utilizes a double-lumen needle to allow for core-shell structures to form. The microcapsules were used for co-culturing hDPSCs and HUVECs to harvest large amounts of prevascularized microtissues, which further showed improved vascularization and pulp-like tissue regeneration in vivo. This CEM method and the microcapsule system have advantages of high-throughput generation, convenient collection, and avoid aggregation during long-term culturing. We proposed a high-effective platform for mass production of prevascularized microtissues, which exhibit great promise in the clinical transformation of endodontic regeneration and other applications in regenerative medicine.

Infected alveolar bone defects pose challenging clinical issues due to disrupted intrinsic healing mechanisms. Thus, the employment of advanced biomaterials enabling the modulation of several aspects of bone regeneration is necessary. This study investigated the effect of multi-functional nanoparticles on anti-inflammatory/osteoconductive characteristics and bone repair in the context of inflamed bone abnormalities. Tannic-acid mineral nanoparticles (TMPs) were prepared by the supramolecular assembly of tannic acid with bioactive calcium and phosphate ions, which were subsequently incorporated into collagen plugs via molecular interactions. Under physiological conditions, in vitro analysis confirmed that tannic acid was dissociated and released, which significantly reduced the expression of pro-inflammatory genes in lipopolysaccharide (LPS)-activated RAW264.7 cells. Meanwhile, the bioactive ions of Ca2+ and PO43- synergistically increased the gene and protein expressions of osteogenic markers of bone marrow-derived stem cells. For in vivo studies, combined endodontic-periodontal lesions were induced in beagle dogs where the plugs were readily implanted. After 2 months of the implantation, analysis of micro-computed tomography and histomorphometry revealed that groups of dogs implanted with the plug incorporating TMPs exhibited a significant decrease in bone surface density as well as structural model index, and significant increase in the mineralized bone content, respectively, with positive OPN expression being observed in reversal lines. Notably, the profound improvement in bone regeneration relied on the concentration of TMPs in the implants, underscoring the promise of multi-functional nanoparticles for treating infected alveolar bones.

The microsphere system has attracted considerable attention as a stem-cell delivery vehicle in regeneration medicine owing to its injectability, fast substance transfer ability, and mimicry of the three-dimensional native environment. However, suitable biomaterials for preparation of microspheres optimal for endodontic regeneration are still being explored. Owing to its excellent bioactivity and biodegradability, gelatin methacryloyl (GelMA) was used to fabricate hydrogel microspheres by the electrostatic microdroplet method, and the potential of GelMA microspheres applied in endodontic regeneration was studied. The average size of GelMA microspheres encapsulating human dental pulp stem cells (hDPSCs) was ~200 μm, and the Young's modulus was approximately 582.8 ± 66.0 Pa, which was close to that of the natural human dental pulp. The encapsulated hDPSCs could effectively adhere, spread, proliferate, and secrete extracellular matrix proteins in the microspheres, and tended to occupy the outer layer. Moreover, the cell-laden GelMA microsphere system could withstand cryopreservation, and the thawed cells exhibited normal functions. After subcutaneous implantation in a nude mouse model, more vascularized pulp-like tissues were generated in the cell-laden GelMA microsphere group compared with that in the cell-laden bulk GelMA group, and this was accompanied by a suitable degradation rate. The GelMA microspheres showed remarkable performances and great potential as cell delivery vehicles in endodontic regeneration.

The sufficient imitation of tissue structures and components represents an effective and promising approach for tissue engineering and regenerative medicine applications. Dental pulp disease is one of the most common oral diseases, although functional pulp regeneration remains challenging. Herein, we propose a strategy that employs hydrogel microspheres incorporated with decellularized dental pulp matrix-derived bioactive factors to simulate a pulp-specific three-dimensional (3D) microenvironment. The dental pulp microenvironment-specific microspheres constructed by this regenerative strategy exhibited favorable plasticity, biocompatibility, and biological performances. Human dental pulp stem cells (hDPSCs) cultured on the constructed microspheres exhibited enhanced pulp-formation ability in vitro. Furthermore, the hDPSCs-microcarriers achieved the regeneration of pulp-like tissue and new dentin in a semi-orthotopic model in vivo. Mechanistically, the decellularized pulp matrix-derived bioactive factors mediated the multi-directional differentiation of hDPSCs to regenerate the pulp tissue by eliciting the secretion of crucial bioactive cues. Our findings demonstrated that a 3D dental pulp-specific microenvironment facilitated by hydrogel microspheres and dental pulp-specific bioactive factors regenerated the pulp-dentin complex and could be served as a promising treatment option for dental pulp disease. STATEMENT OF SIGNIFICANCE: Injectable bioscaffolds are increasingly used for regenerative endodontic treatment. Despite their success related to their ability to load stem cells, bioactive factors, and injectability, conventional bulk bioscaffolds have drawbacks such as ischemic necrosis in the central region. Various studies have shown that ischemic necrosis in the central region can be corrected by injectable hydrogel microspheres. Unfortunately, pristine microspheres or microspheres without dental pulp-specific bioactive factor would oftentimes fail to regulate stem cells fates in dental pulp multi-directional differentiation. Our present study reported the biofabrication of dental pulp-derived decellularized matrix functionalized gelatin microspheres, which contained dental pulp-specific bioactive factors and have the potential application in endodontic regeneration.

To address the challenges posed by biofilm presence and achieve a substantial reduction in bacterial load within root canals during endodontic treatment, various irrigants, including nanoparticle suspensions, have been recommended. Berberine (BBR), a natural alkaloid derived from various plants, has demonstrated potential applications in dentistry treatments due to its prominent antimicrobial, anti-inflammatory, and antioxidant properties. This study aimed to produce and characterize a novel polymeric nanoparticle of poly (lactic-co-glycolic acid) (PLGA) loaded with berberine and evaluate its antimicrobial activity against relevant endodontic pathogens, Enterococcus faecalis, and Candida albicans. Additionally, its cytocompatibility using gingival fibroblasts was assessed. The polymeric nanoparticle was prepared by the nanoprecipitation method. Physicochemical characterization revealed spheric nanoparticles around 140 nm with ca, −6 mV of surface charge, which was unaffected by the presence of BBR. The alkaloid was successfully incorporated at an encapsulation efficiency of 77% and the designed nanoparticles were stable upon 20 weeks of storage at 4 °C and 25 °C. Free BBR reduced planktonic growth at ≥125 μg/mL. Upon incorporation into PLGA nanoparticles, 20 μg/mL of [BBR]-loaded nanoparticles lead to a significant reduction, after 1 h of contact, of both planktonic bacteria and yeast. Sessile cells within biofilms were also considered. At 30 and 40 μg/mL, [BBR]-loaded PLGA nanoparticles reduced the viability of the sessile endodontic bacteria, upon 24 h of exposure. The cytotoxicity of BBR-loaded nanoparticles to oral fibroblasts was negligible. The novel berberine-loaded polymeric nanoparticles hold potential as a promising supplementary approach in the treatment of endodontic infections.

Dental pulp is a major component of the dental body that serves to maintain the tooth life and function. The aim of the present work was to develop a system that functions as a growth-permissive microenvironment for dental pulp regeneration using a decellularized dental pulp (DDP) matrix, 5-Aza-2′-deoxycytidine (5-Aza), and Extracellular Vesicles (EVs) derived from human Dental Pulp Stem Cells (hDPSCs). Human dental pulps extracted from healthy teeth, scheduled to be removed for orthodontic purpose, were decellularized and then recellularized with hDPSCs. The hDPSCs were seeded on DDP and maintained under different culture conditions: basal medium (CTRL), EVs, 5-Aza, and EVs+-5-Aza. Immunofluorescence staining and Western blot analyses were performed to evaluate the proteins’ expression related to dentinogenesis, such as ALP, RUNX2, COL1A1, Vinculin, DMP1, and DSPP. Protein contents found in the DDP recellularized with hDPSCs were highly expressed in samples co-treated with EVs and 5-Aza compared to other culture conditions. This study developed a DDP matrix loaded by hDPSCs in co-treatment with EVs, which might enhance the dentinogenic differentiation with a high potentiality for endodontic regeneration.

ABSTRACT Background: The application of nanoparticles in endodontic treatment presents a novel approach to drug delivery, potentially enhancing the efficacy of therapeutic agents. Materials and Methods: In this study, we synthesized and characterized nanoparticles of chitosan, calcium phosphate, and silver using standard protocols. The nanoparticles were then loaded with an antimicrobial agent, chlorhexidine, and incorporated into an endodontic sealer. The antibacterial efficacy of the nanoparticle-enhanced sealer was tested against Enterococcus faecalis using a disk diffusion method. Additionally, the penetration depth of nanoparticles into dentinal tubules was assessed using scanning electron microscopy (SEM). Results: The synthesized nanoparticles exhibited a uniform size distribution, with an average diameter of 50 nm for chitosan, 30 nm for calcium phosphate, and 20 nm for silver nanoparticles. The antibacterial tests showed that the nanoparticle-loaded sealer achieved a 40% greater inhibition zone against Enterococcus faecalis compared to the control sealer without nanoparticles. SEM analysis revealed that the nanoparticles penetrated dentinal tubules to a depth of approximately 500 μm, significantly more than the conventional sealer. Conclusion: Nanoparticles demonstrate significant potential as a drug delivery system in endodontic treatment, enhancing both the antibacterial efficacy and penetration depth of therapeutic agents.

Rapid angiogenesis is one of the challenges in endodontic regeneration. Recently, tailored polymeric microsphere system that loaded pro-angiogenic growth factors (GFs) is promising in facilitating vascularization in dental pulp regeneration. In addition, the synergistic effect of multiple GFs is considered more beneficial, but combination usage of them is rather complex and costly. Herein, we aimed to incorporate human platelet lysates (PL), a natural-derived pool of multiple GFs, into gelatin methacrylate (GelMA) microsphere system (GP), which was further modified by Laponite (GPL), a nanoclay with efficient drug delivery ability. These hybrid microspheres were successfully fabricated by electrostatic microdroplet technique with suitable size range (180∼380 μm). After incorporation of the PL and Laponite with GelMA, the Young's modulus of the hybrid hydrogel increased up to about 3-fold and the swelling and degradation rate decreased simultaneously. The PL-derived GFs continued to release up to 28 days from both the GP and GPL microspheres, while the latter released relatively more slowly. What's more, the released GFs could effectively induce tubule formation of human umbilical endothelial cells (HUVECs) and also promote human dental pulp stem cells (hDPSCs) migration. Additionally, the PL component in the GelMA microspheres significantly improved the proliferation, spreading, and odontogenic differentiation of the encapsulated hDPSCs. As further verified by the subcutaneous implantation results, both of the GP and GPL groups enhanced microvascular formation and pulp-like tissue regeneration. This work demonstrated that PL-incorporating GelMA microsphere system was a promising functional vehicle for promoting vascularized endodontic regeneration. STATEMENT OF SIGNIFICANCE: : Polymeric microsphere system loaded with pro-angiogenic growth factors (GFs) shows great promise for regeneration of vascularized dental pulp. Herein, we prepared a functional GelMA microsphere system incorporated with human platelet lysates (PL) and nanoclay Laponite by the electrostatic microdroplet method. The results demonstrated that the GelMA/PL/Laponite microspheres significantly improved the spreading, proliferation, and odontogenic differentiation of the encapsulated hDPSCs compared with pure GelMA microspheres. Moreover, they also enhanced microvascular formation and pulp-like tissue regeneration in vivo. This hybrid microsphere system has great potential to accelerate microvessel formation in regenerated dental pulp and other tissues.

Considering the complicated and irregular anatomical structure of root canal systems, injectable microspheres have received considerable attention as cell carriers in endodontic regeneration. Herein, we developed injectable hybrid RGD-alginate/laponite (RGD-Alg/Lap) hydrogel microspheres, co-encapsulating human dental pulp stem cells (hDPSCs) and vascular endothelial growth factor (VEGF). These microspheres were prepared by the electrostatic microdroplet method with an average size of 350∼450 μm. By adjusting the content of laponite, the rheological properties and the degradation rate of the microspheres in vitro could be conditioned. The release of VEGF from the RGD-Alg/0.5%Lap microspheres was in a sustained manner for 28 days while the bioactivity of VEGF was preserved. In addition, the encapsulated hDPSCs were evenly distributed in microspheres with a cell viability exceeding 85%. The deposition of abundant extracellular matrix such as fibronectin (FN) and collagen type I (Col-I) was shown in microspheres after 7 days. The laponite in the system significantly up-regulated the expression of odontogenic-related genes of hDPSCs at day 7. Furthermore, after subcutaneous implantation with tooth slices in a nude mouse model for 1 month, the hDPSCs-laden RGD-Alg/0.5%Lap+VEGF microspheres significantly promoted the regeneration of pulp-like tissues as well as the formation of new micro-vessels. These results demonstrated the great potential of laponite-enhanced hydrogel microspheres in vascularized dental pulp regeneration.

AIM The aim of current study is the development and optimization of biodegradable polymeric nanoparticles (NPs) to be used in the field of Endodontics as intracanal medication in cases of avulsed teeth with extended extra-oral time, utilizing PLGA polymers loaded with the anti-inflammatory drug clobetasol propionate (CP). METHODOLOGY CP-loaded nanoparticles (CP-NPs) were prepared using the solvent displacement method. CP release profile from CP-NPs was assessed for 48 h against free CP. Using extracted human teeth, the degree of infiltration inside the dentinal tubules was studied for both CP-NPs and CP. The anti-inflammatory capacity of CP-NPs was evaluated in vitro measuring their response and reaction against inflammatory cells, in particular against macrophages. The enzyme-linked immunosorbent assay (ELISA) was used to examine the cytokine release of IL-1β and TNF-α. RESULTS Optimized CP-NPs displayed an average size below 200 nm and a monomodal population. Additionally, spherical morphology and non-aggregation of CP-NPs were confirmed by transmission electron microscopy. Interaction studies showed that CP was encapsulated inside the NPs and no covalent bonds were formed. Moreover, CP-NPs exhibited a prolonged and steady release with only 21% of the encapsulated CP released after 48 h. Using confocal laser scanning microscopy, it was observed that CP-NPs were able to display enhanced penetration into the dentinal tubules. Neither the release of TNF-α nor IL-1β increased in CP-NPs compared to the LPS control, displaying results similar and even less than the TCP after 48 h. Moreover, IL-1β release in LPS-stimulated cells, decreased when macrophages were treated with CP-NPs. CONCLUSIONS In the present work, CP-NPs were prepared, optimized and characterized displaying significant increase in the degree of infiltration inside the dentinal tubules against CP and were able to significantly reduce TNF-α release. Therefore, CP-NPs constitute a promising therapy for the treatment of avulsed teeth with extended extra-oral time.

According to the Centers for Disease Control and Prevention, tooth caries is a common problem affecting 9 out of every 10 adults worldwide. Dentin regeneration has since become one of the pressing issues in dentistry with tissue engineering emerging as a potential solution for enhancing dentin regeneration. In this study, we fabricated cell blocks with human dental pulp stem cells (hDPSCs)-laden alginate/fish gelatin hydrogels (Alg/FGel) at the center of the cell block and human umbilical vascular endothelial cells (HUVEC)-laden Si ion-infused fish gelatin methacrylate (FGelMa) at the periphery of the cell block. 1H NMR and FTIR results showed the successful fabrication of Alg/FGel and FGelMa. In addition, Si ions in the FGelMa were noted to be bonded via covalent bonds and the increased number of covalent bonds led to an increase in mechanical properties and improved degradation of FGelMa. The Si-containing FGelMa was able to release Si ions, which subsequently significantly not only enhanced the expressions of angiogenic-related protein, but also secreted some cytokines to regulate odontogenesis. Further immunofluorescence results indicated that the cell blocks allowed interactions between the HUVEC and hDPSCs, and taken together, were able to enhance odontogenic-related markers’ expression, such as alkaline phosphatase (ALP), dentin matrix phosphoprotein-1 (DMP-1), and osteocalcin (OC). Subsequent Alizarin Red S stain confirmed the benefits of our cell block and demonstrated that such a novel combination and modification of biomaterials can serve as a platform for future clinical applications and use in dentin regeneration.

The utility and feasibility of pulp regenerative therapy with autologous dental pulp stem cells (DPSCs) in mature teeth with irreversible pulpitis were clinically demonstrated. On the other hand, there is no evidence of the utility of DPSCs in mature teeth with apical periodontitis. The aim of this case report is to describe the potential utility of regenerative cell therapy in mature teeth with apical periodontitis. A 44-year-old male was referred for the pulp regeneration of his maxillary first premolar with a periapical lesion. Root canal disinfection was performed by irrigation and intracanal medication by nanobubbles with levofloxacin and amphotericin B in addition to conventional irrigation. Autologous DPSCs isolated from an extracted third molar were transplanted into the root canal after residual bacteria and fungi were below the detection level by PCR assay using universal genes to amplify specific regions within bacterial 16S rDNA and fungal rDNA (ITS1), respectively. There was no adverse events or systemic toxicity assessed for clinical evaluations during the 79 week-follow-up period and laboratory evaluations after 4 weeks. The affected tooth was responsive to the electric pulp test. The cone-beam computed tomographic (CBCT) imaging revealed much reduced lesion size, remission of the periapical tissue and mineralized tissue formation in the apical part of the canal after 79 weeks. The signal intensity on magnetic resonance imaging of the regenerated tissue in the affected tooth was comparable to that of the normal pulp in the adjacent teeth after 24 weeks. This case report demonstrated the potential use of DPSCs for pulp regenerative therapy in mature teeth with apical periodontitis.

No abstract available

Repairing critical-sized bone defects represents a major challenge in clinical therapeutics due to inhibited osteogenic differentiation, harsh bone tissue microenvironment, and abnormal inflammatory response. Mesenchymal stem cell-derived exosomes (MSC-Exos) have demonstrated tremendous regenerative potential in tissue repair. However, the confined therapeutic efficacy, deficient targeting capability, and poor retention rate have rendered MSC-Exos-based cell-free therapies insufficient for clinical bone defect repair. This study prepared curcumin-loaded MSC-Exos (Cur@Exos) based on an endogenous drug delivery approach and encapsulated in bisphosphonate-modified GelMA hydrogel microspheres by microfluidics. The CE@BP-Gel microspheres demonstrated superior biocompatibility and were competent to accelerate biomineralization. The sustained-release Cur@Exos in the composite hydrogel microspheres actively regulated the polarization of RAW264.7 cells toward the regenerative M2 type and inhibited the osteoclastic activity, thereby creating an immune microenvironment suitable for osteogenesis. Meanwhile, the composite hydrogel microspheres can directly support the adhesion, proliferation and osteogenic differentiation of BMSCs and facilitate the migration and angiogenesis of HUVECs. In vivo experiments demonstrated that the CE@BP-Gel microspheres significantly accelerated the repair of critical-sized cranial bone defects in SD rats. The targets and mechanisms of action of CE@BP-Gel in bone immune regulation were investigated based on network pharmacology, molecular dynamics simulation and RNA sequencing. It was found that CE@BP-Gel mitigates DNA damage induced by ROS in inflammatory environments. The encapsulated curcumin enhances DNA damage repair by activating the TDP1 enzyme, consequently reducing the expression of inflammatory factors in macrophages. This study demonstrates a promising therapeutic strategy to design an exosome-based drug delivery system for bone defect repair.

Bone integrity is maintained through continuous remodeling, orchestrated by the coordinated actions of osteocytes, osteoblasts, and osteoclasts. Once considered passive bystanders, osteocytes are now recognized as central regulators of this process, mediating biochemical signaling and mechanotransduction. Malfunctioning osteocytes contribute to serious skeletal disorders such as osteoporosis. Mesenchymal stromal cells (MSCs), multipotent stem cells capable of differentiating into osteoblasts, have emerged as promising agents for bone regeneration, primarily through the paracrine effects of their secreted exosomes. MSC-derived exosomes are nanoscale vesicles enriched with proteins, lipids, and nucleic acids that promote intercellular communication, osteoblast proliferation and differentiation, and angiogenesis. Notably, they deliver osteoinductive microRNAs (miRNAs) that influence osteogenic markers and support bone tissue repair. In vivo investigations validate their capacity to enhance bone regeneration, increase bone volume, and improve biomechanical strength. Additionally, MSC-derived exosomes regulate the immune response, creating pro-osteogenic and pro-angiogenic factors, boosting their therapeutic efficacy. Due to their cell-free characteristics, MSC-derived exosomes offer benefits such as diminished immunogenicity and minimal risk of off-target effects. These properties position them as promising and innovative approaches for bone regeneration, integrating immunomodulatory effects with tissue-specific regenerative capabilities.

Aging impairs bone marrow mesenchymal stem cell (BMSC) functions as well as associated angiogenesis which is critical for bone regeneration and repair. Hence, repairing bone defects in elderly patients poses a formidable challenge in regenerative medicine. Here, the engineered dental pulp stem cell‐derived exosomes loaded with the natural derivative of adenosine Cordycepin (CY@D‐exos) are fabricated by means of the intermittent ultrasonic shock, which dually rejuvenates both senescent BMSCs and endothelial cells and significantly improve bone regeneration and repair in aged animals. CY@D‐exos can efficiently overcome the senescence of aged BMSCs and enhance their osteogenic differentiation by activating NRF2 signaling and maintaining heterochromatin stability. Importantly, CY@D‐exos also potently overcomes the senescence of vascular endothelial cells and promotes angiogenesis. In vivo injectable gelatin methacryloyl (GelMA) hydrogels with sustained release of CY@D‐exos can accelerate bone injury repair and promote new blood vessel formation in aged animals. Taken together, these results thus demonstrate that cordycepin‐loaded dental pulp stem cell‐derived exosomes display considerable potential to be developed as a next‐generation therapeutic agent for promoting aged bone regeneration and repair.

Blood glucose fluctuation leads to poor bone defect repair in patients with type 2 diabetes (T2DM). Strategies to safely and efficiently improve the bone regeneration disorder caused by blood glucose fluctuation are still a challenge. Neutral sphingophospholipase 2 (Smpd3) is downregulated in jawbone-derived bone marrow mesenchymal stem cells (BMSCs) from T2DM patients. Here, we investigated the effect of Smpd3 on the osteogenic differentiation of BMSCs and utilized exosomes from stem cells overexpressing Smpd3 as the main treatment based on the glucose responsiveness of phenylboronic acid-based polyvinyl alcohol crosslinkers and the protease degradability of gelatin nanoparticles. The combined loading of Smpd3-overexpressing stem cell-derived exosomes (Exos-Smpd3) and nanosilver ions (Ns) to construct a hydrogel delivery system (Exos-Smpd3@Ns) promoted osteogenesis and differentiation of BMSCs in a glucose-fluctuating environment, ectopic osteogenesis of BMSCs in a glucose-fluctuating environment and jawbone regeneration of diabetic dogs in vitro. Mechanistically, Smpd3 promoted the osteogenesis and differentiation of jawbone-derived BMSCs by activating autophagy in the jawbone and inhibiting macrophage polarization and oxidative stress caused by blood glucose fluctuations. These results reveal the role and mechanism of Smpd3 and the Smpd3 overexpression exosome delivery system in promoting BMSC function and bone regeneration under blood glucose fluctuations, providing a theoretical basis and candidate methods for the treatment of bone defects in T2DM patients.

The repair of bone defects remains a huge clinical challenge. M2 macrophage-derived exosomes (M2-Exos) can act as immunomodulators to promote fracture healing; however, how to retain the sustained release of exosomes to the target area remains a challenge. Here, we report a composite hydrogel loaded with M2-Exos aiming to accelerate bone defect healing. It was verified that the F127/HA-NB hydrogel had a dense network structure, tissue adhesiveness, and dual sensitivity to temperature and light. F127/HA-NB loaded with M2-Exos (M2-Exos@F127/HA-NB) exhibited good biocompatibility and achieved sustained release of exosomes for up to two weeks. The study showed that both M0-Exos and M2-Exos@F127/HA-NB significantly promoted osteogenic differentiation of rat bone marrow mesenchymal stem cells. The mechanism study implied that M2-Exos activates the Wnt/β-catenin signaling pathway to promote osteogenic differentiation of BMSCs. Finally, we evaluated the osteogenetic effects of M2-Exos@F127/HA-NB in a rat cranial defect model, and the results showed that M2-Exos@F127/HA-NB had superior bone regeneration-promoting effects. This study provides a new strategy for cell-free treatment of bone defects.

The osteogenic function of mesenchymal stem cells (MSCs) is mainly attributed to the paracrine effect of extracellular vesicles. MSC-derived exosomes are interesting candidates as biopharmaceuticals for drug delivery and for the engineering of biologically functionalized materials, and have emerged as cell-free regenerative medicine in recent years. In this study, bone marrow mesenchymal stem cell (BMSC)-derived exosomes were loaded with photothermal material layered black phosphorus (BP) modified poly(N-isopropylacrylamide) (PNIPAAm) thermosensitive hydrogels to explore their effects on bone defect repair. In vitro, it was confirmed that the local high heat of nano-BP irradiated using a near-infrared (NIR) laser could trigger the reversible cascade reaction of hydrogels, and that the mechanical contraction of hydrogels led to the controllable release of a large number of exosomes along with the release of water molecules. Furthermore, in vitro investigations demonstrated that BP hydrogels loaded with BMSC-derived exosomes had favourable biocompatibility and could promote the proliferation and osteogenic differentiation of MSCs. Experiments conducted in vivo confirmed that this system significantly promoted bone regeneration. Therefore, the results of our study indicated that the nanoplatform based on BP thermosensitive hydrogels could provide a new clinical treatment strategy for controlled release and on-demand drug delivery, while the cell-free system composed of BMSC-derived exosomes had great application potential in bone tissue repair with the synergism of BP.

As a traditional bone implant material, titanium (Ti) and its alloys have the disadvantages of lack of biological activity and susceptibility to stress shielding effect. Adipose stem cells (ADSCs) and exosomes were combined with the scaffold material in the current work to effectively create a hydroxyapatite (HA) coated porous titanium alloy scaffold that can load ADSCs and release exosomes over time. The composite made up for the drawbacks of traditional titanium alloy materials with higher mechanical characteristics and a quicker rate of osseointegration. Exosomes (Exos) are capable of promoting the development of ADSCs in porous titanium alloy scaffolds with HA coating, based on experimental findings from in vitro and in vivo research. Additionally, compared to pure Ti implants, the HA scaffolds loaded with adipose stem cell exosomes demonstrated improved bone regeneration capability and bone integration ability. It offers a theoretical foundation for the combined use of stem cell treatment and bone tissue engineering, as well as a design concept for the creation and use of novel clinical bone defect repair materials.

Prolonged oxidative stress and reduced activity of mesenchymal stem cells are significant barriers to effective bone repair. Current therapeutic approaches often suffer from limited long-term efficacy due to inefficient exosome delivery and the degradation of biological materials. Here, we present an electroactive gelatin methacryloyl hydrogel incorporating a tannic acid-mediated conductive polypyrrole microfiber network and exosomes armored with a metal-polyphenol network, designed to mitigate chronic inflammation and enhance bone healing. The iron-tannic acid complex forms a protective coating on the surface of exosomes, shielding them from damage in inflammatory environments and promoting osteoblast differentiation. This is achieved by enabling exosomes to evade lysosomal degradation through the proton sponge effect. Additionally, the phenolic hydroxyl groups of tannic acid effectively scavenge reactive oxygen species at injury sites. By delivering electrical stimulation to mimic the native electrophysiological environment, the catechol-quinone redox balance is maintained, providing sustained antioxidant effects. In a rat bone defect model, this multifunctional hydrogel demonstrated robust activity for bone regeneration. These findings demonstrated the ability of this electroactive hydrogel system to enhance exosome delivery, provide long-term antioxidative activity, and promote osteogenic differentiation, offering a promising therapeutic platform for bone tissue engineering.

The periosteum, a fibrous tissue membrane covering bone surfaces, is critical to osteogenesis and angiogenesis in bone reconstruction. Artificial periostea have been widely developed for bone defect repair, but most of these are lacking of periosteal bioactivity. Herein, a biomimetic periosteum (termed PEC-Apt-NP-Exo) is prepared based on an electrospun membrane combined with engineered exosomes (Exos). The electrospun membrane is fabricated using poly(ε-caprolactone) (core)-periosteal decellularized extracellular matrix (shell) fibers via coaxial electrospinning, to mimic the fibrous structure, mechanical property, and tissue microenvironment of natural periosteum. The engineered Exos derived from M2 macrophages are functionalized by surface modification of bone marrow mesenchymal stem cell (BMSC)-specific aptamers to further enhance cell recruitment, immunoregulation, and angiogenesis in bone healing. The engineered Exos are covalently bonded to the electrospun membrane, to achieve rich loading and long-term effects of Exos. In vitro experiments demonstrate that the biomimetic periosteum promotes BMSC migration and osteogenic differentiation via Rap1/PI3K/AKT signaling pathway, and enhances vascular endothelial growth factor secretion from BMSCs to facilitate angiogenesis. In vivo studies reveal that the biomimetic periosteum promotes new bone formation in large bone defect repair by inducing M2 macrophage polarization, endogenous BMSC recruitment, osteogenic differentiation, and vascularization. This research provides valuable insights into the development of a multifunctional biomimetic periosteum for bone regeneration.

Mesenchymal stem cell-derived exosomes (MSC-exos), with its inherent capacity to modulate cellular behavior, are emerging as a novel cell-free therapy for bone regeneration. Herein, focusing on practical applying problems, the osteoinductivity of MSC-exos produced by different stem cell sources (rBMSCs/rASCs) and culture conditions (osteoinductive/common) were systematically compared to screen out an optimized osteogenic exosome (BMSC-OI-exo). Via bioinformatic analyses by miRNA microarray and in vitro pathway verification by gene silencing and miRNA transfection, we first revealed that the osteoinductivity of BMSC-OI-exo was attributed to multi-component exosomal miRNAs (let-7a-5p, let-7c-5p, miR-328a-5p and miR-31a-5p). These miRNAs targeted Acvr2b/Acvr1 and regulated the competitive balance of Bmpr2/Acvr2b toward Bmpr-elicited Smad1/5/9 phosphorylation. On these bases, lyophilized delivery of BMSC-OI-exo on hierarchical mesoporous bioactive glass (MBG) scaffold was developed to realize bioactivity maintenance and sustained release by entrapment in the surface microporosity of the scaffold. In a rat cranial defect model, the loading of BMSC-OI-exo efficiently enhanced the bone forming capacity of the scaffold and induced rapid initiation of bone regeneration. This paper could provide empirical bases of MSC-exo-based therapy for bone regeneration and theoretical bases of MSC-exo-induced osteogenesis mechanism. The BMSC-OI-exo-loaded MBG scaffold developed here represented a promising bone repairing strategy for future clinical application.

Accelerating angiogenesis, neurogenesis, and in situ stem cell recruitment at the site of bone defects is critical for bone regenerative repair. Bone marrow mesenchymal stem cell (BMSC) exosomes are cell-free therapeutic agents with bone-enhancing effects. Thymosin β4 (Tβ4) is a short peptide known for its key role in tissue repair and angiogenesis. In this study, we successfully developed a multifunctional injectable Exo@Tβ4/HAMA hydrogel platform by grafting Tβ4 onto methylmalonic anhydride-modified hyaluronic acid (HAMA) via photo-cross-linking and then encapsulating BMSC-derived exosomes. In vitro results demonstrated that the Exo@Tβ4/HAMA hydrogel exhibited improved mechanical properties, favorable biocompatibility, and the ability to significantly recruit BMSCs. Additionally, it showed superior vasculogenic effects on HUVECs and osteogenic differentiation potentials on BMSCs. In vivo studies revealed that the hydrogel successfully promoted both neurogenesis, angiogenesis, and new bone formation. It also facilitated osteogenesis through the ERK1/2-dependent RUNX2 signaling pathway. Our results suggest that this hydrogel platform exerts a robust multisystemic regulatory effect, fostering rat bone repair through the synergistic promotion of in situ stem cell recruitment, angiogenesis, neurogenesis, and osteogenesis. As a simple-to-prepare and multifunctional integrated bone graft, this hydrogel platform holds a significant promise in establishing a conducive microenvironment for optimal bone healing.

A varied family of polyphenolic chemicals, flavonoids, are becoming more and more important in bone tissue engineering because of their osteogenic, anti-inflammatory, and antioxidant effects. Recent developments incorporating flavonoids into different biomaterial platforms to improve bone regeneration are emphasized in this study. Osteocalcin (OCN) expression was 2.1-fold greater in scaffolds loaded with flavonoids—such as those made of polycaprolactone (PCL)—greatly increasing human mesenchymal stem cell (hMSC) proliferation and mineralization. Comparably, a threefold increase in calcium deposition indicates increased mineralization when hydroxyapatite (HA) was functionalized with flavonoids such as quercetin. These HA scaffolds with flavonoids also showed a 45% decrease in osteoclast activity, therefore promoting balanced bone remodeling. Concurrent with flavonoids like EGCG and quercetin, chitosan-based scaffolds encouraged osteogenic differentiation with increases in osteogenic markers like osteopontin (OPN) and alkaline phosphatase (ALP) expression by up to 82%. These scaffolds also showed 82% bone defect repair after six weeks in vivo, suggesting their promise in rapid bone regeneration. With an increase of up to 32% in the bone volume-to-total volume ratio (BV/TV) and 28% greater bone–implant contact (BIC), flavonoid coatings on titanium implants enhanced osteointegration in implantology. Displaying successful osteogenesis and immunomodulation, the addition of flavonoids into metal–organic frameworks (MOFs) and injectable hydrogels demonstrated a 72% increase in new bone formation in vivo. Though further research is required to confirm long-term clinical effectiveness, these findings show the great promise of flavonoid-functionalized biomaterials in bone regeneration.

Age-related bone defects cause disability and mortality in older individuals. During bone repair in older individuals, high oxidative stress and excessive inflammation in the senescent microenvironment (SME) lead to bone marrow mesenchymal stem cell (BMSC) senescence, thereby affecting bone regeneration. In this study, we prepared multifunctional magnesium (Mg) and cerium (Ce) ion-based metal-organic frameworks (MOFs) using a hydrothermal method and constructed a three-dimensional (3D) bioprinted scaffold to effectively scavenge reactive oxygen species (ROS) and sustainably release Mg2+ to improve the SME and age-related bone defect repair. Under oxidative stress, the scaffolds delayed the senescence of loaded BMSCs and promoted M2 macrophage polarization of RAW264.7 cells, further improving BMSC osteogenic differentiation. In addition, Mg2+ release promoted aldehyde dehydrogenase 3A1 expression through the activation of the nuclear factor E2-related factor 2 (Nrf2) signaling pathway, thereby delaying BMSC senescence. Adding the Wnt/β-catenin agonist SKL2001 to the scaffolds further enhanced these effects. Finally, the composite scaffolds accelerated the repair of critical-sized calvarial defects in an aged rat model. In summary, these results demonstrated the value of improving the SME for delaying BMSC senescence using multifunctional Mg-Ce-MOF and SKL2001-based 3D-bioprinting scaffolds, thereby providing an effective strategy for promoting age-related bone defect repair.

The fascial space of the oral and maxillofacial region contains loose connective tissues, which possess weak anti-infection ability and are often prone to infection, leading to acute suppurative inflammation and sepsis through blood. Although antibiotic use can reduce the probability of bacterial infections, owing to the emergence of antibiotic-resistant bacteria, the search for new antimicrobial drugs is imminent. Herein, we report a metal–organic framework (MOF) antibacterial material designed and synthesized with gallium (Ga) as the central atom, which possesses significant antibacterial, anti-inflammatory, and antioxidant effects. Our data suggested that GA-based MOFs (Ga–MOFs; 1 μg/mL) could sufficiently kill Porphyromonas gingivalis, Streptococcus pyogenes, and Staphylococcus aureus. Ga–MOFs exhibited a bactericidal effect against these three pathogens by disrupting biofilm formation, exopolysaccharide production, and bacterial membrane integrity. In addition, we found that 1 μg/mL of Ga–MOFs was not cytotoxic to human oral epithelial cell (HOEC) lines and it significantly reduced the adhesion of the three pathogens to HOEC. Ga–MOFs protect macrophages from excessive oxidative stress by scavenging excess intracellular reactive oxygen species and upregulating antioxidant gene levels, thereby enhancing cellular antioxidant defense. In addition, Ga–MOFs can promote the transformation of macrophages from the proinflammatory phenotype to the anti-inflammatory phenotype, thereby protecting oral health. Herein, novel Ga–MOF materials were chemically synthesized for therapeutic applications in oral infections, which provides new ideas for the development of novel nonantibiotic drugs to accelerate patient recovery.

The regeneration of diabetic bone defects remains challenging. Hyperglycemia causes inflammation state and excessive reactive oxygen species (ROS) during bone regeneration period. These two effects reinforce one another and create an endless loop that is also accompanied by mitochondrial dysfunction. However, there is still no effective and inclusive method targeting at the two aspects and breaking the vicious cycle. Herein, nanoparticles-Met@ZIF-8(metformin loaded zeolitic imidazolate frameworks) modified hydrogel that is capable of releasing metformin and Zn elements are constructed. This hydrogel treats hyperglycemia while also controlling mitochondrial function, reducing inflammation, and restoring homeostasis. In addition, the synergetic effect from metformin and Zn ions inhibits ROS-inflammation cascade generation and destroys the continuous progress by taking effects in both ROS and inflammation and further keeping organelles' homeostasis. Furthermore, with the recovery of mitochondria and breakdown of the ROS-inflammation cascade cycle, osteogenesis under a diabetic microenvironment is enhanced in vivo and in vitro. In conclusion, the study provides critical insight into the biological mechanism and potential therapy for diabetic bone regeneration.

Fungal infections associated with oral, gynecological, and skin ailments pose significant clinical challenges. The presence of biofilms often hampers the efficacy of conventional antifungal drugs owing to the complex microenvironment they create. In this study, the widely used antifungal medication fluconazole is utilized as a foundational component to be incorporated into zinc 2-methylimidazolate frameworks, resulting in the synthesis of nanoscale fluconazole-constructed metal-organic frameworks (F-ZIF). The F-ZIF is constructed through coordination interactions between zinc and fluconazole, retaining the structure and pH-responsiveness of the zinc 2-methylimidazolate framework. The pH-responsiveness F-ZIF makes sure the fluconazole can be released in acidic biofilm, which prevents the undesired release in healthy tissue, resulting in good biocompatibility both in vitro and in vivo. The in vitro studies demonstrated that F-ZIF exhibits enhanced efficacy in eradicating fungal pathogens in their biofilm growth state compared with the free fluconazole. Furthermore, in vivo experiments reveal the better effectiveness of F-ZIF in treating Candida albicans-induced vulvovaginal candidiasis, and less infection-related inflammation was observed. Hence, the one-port synthetic F-ZIF presents a promising solution for addressing fungal biofilm-related infections.

Exosomes are natural membrane-enclosed nanovesicles (30–150 nm) involved in cell-cell communication. Recently, they have garnered considerable interest as nanocarriers for the controlled transfer of therapeutic agents to cells. Here, exosomes were derived from bone marrow mesenchymal stem cells using three different isolation methods. Relative to filtration and spin column condensation, the size exclusion chromatography led to the isolation of exosomes with the highest purity. These exosomes were then hybridized with liposomes using freeze-thaw cycles and direct mixing techniques to evaluate whether this combination enhances the transfection efficiency of large plasmids. The efficiency of these hybrids in transferring the Cas9-green fluorescent protein plasmid (pCas9-GFP) into the human embryonic kidney 293T (HEK293T) cells was evaluated compared to the pure exosomes. Both Cas9-GFP-loaded exosomes and exosome-liposome hybrids were taken up well by the HEK293T cells and were able to transfect them with their plasmid loads. Meanwhile, the treatment of the cells with plasmids alone, without any vesicles, resulted in no transfection, indicating that the exosome and exosome-liposome hybrids are essential for the transfer of the plasmids across the cell membrane. The pure exosomes and the hybrids incorporating liposomes obtained by the heating method transfected the cells more efficiently than those containing liposomes obtained by the thin film hydration technique. Interestingly, the method of combining exosomes with liposomes (freeze-thaw vs. direct mixing) proved to be more decisive in determining the size of the vesicular hybrid than their composition. In contrast, the liposome component in the hybrids proved to be decisive for determining the transfection efficiency.

Abstract We established a proof-of-concept model system for the biological healing of periapical lesions using stem cell spheroids. Mesenchymal stem cells from human exfoliated deciduous teeth (SHED) were cultured in a 2D monolayer and then as 3D multicellular spheroids. An image of a periapical lesion of an upper lateral incisor tooth was obtained by computed tomography and was used as a model for photopolymer resin 3D printing to generate a negative frame of the lesion. The negative model served to prepare a positive model of the periapical lesion cavity in an agarose gel. SHED that were cultured in monolayers or as spheroids were seeded in the positive lesion mold before or after osteoblastic differentiation. The results showed that compared to cells cultured in monolayers, spheroids exhibited uniform cellularity and a greater viability within the lesion cavity, which was accompanied by a temporal reduction in the expression of CD13, CD29, CD44, CD73, and CD90 mRNAs that are typically expressed by stem cells. Concomitantly, the expression of markers that characterize osteoblastic differentiation (RUNX2, ALP, and BGLAP) increased. These results provide a new perspective for regenerative endodontics with the use of SHED-derived spheroids to repair periapical lesions.

The regeneration of the pulp-dentine complex is characterized by organizational diversity, with both dentine and pulp being essential for regenerating a complete tooth-like structure. Matrix stiffness plays a crucial role in guiding the multi-lineage differentiation of stem cells during the regeneration process. However, human dental pulp stem cell (HDPSCs) differentiation via three-dimensional (3D) matrix stiffness is still ambiguous. This study employed gelatin methacryloyl hydrogels of varying stiffness to investigate their effects on HDPSCs differentiation, and constructing a Tri-Phase Biomechanical Structure. The effects of 3D stiffness on HDPSCs proliferation, morphology, differentiation, and biomineralization were examined. The underlying mechanisms were analyzed by RNA sequencing (RNA-seq). At the same time, the comprehensive effects of 3D matrix stiffness-induced HDPSCs paracrine signals on periapical cells (endothelial cells, macrophages and fibroblasts) were evaluated. In vitro, high stiffness promoted dentin differentiation, medium stiffness supported vascular differentiation, and low stiffness enhanced vascularization of peri-apical cells through paracrine signals. In vivo, treated dentin matrixes implanted in nude mice further confirmed that this Tri-Phase Biomechanical Structure effectively promoted crownward dentin formation, pulp-like regeneration within root canals, and integration with periapical tissues. These findings highlight that understanding HDPSCs responses to 3D matrix stiffness is crucial for guiding targeted, efficient regeneration of a tooth-like pulpodentin complex.

In regenerative medicine, the therapeutic potential of mesenchymal stem cells (MSC), such as stem cells from human apical papilla (SCAP), is well-documented and largely attributed to their secretome. However, their poor survival post-transplantation limits their efficacy. This study hypothesized that combining SCAP spheroids with nanomedicines loaded with NecroX-5 (an anti-necrotic drug) and rapamycin (an immunosuppressive agent) would enhance SCAP survival in vivo. The approach aimed to reduce oxidative stress-related cell death and suppress immune reactions towards xeno-/allogenic cells. Two types of nanocarriers, polymeric nanoparticles (NP) and lipid nanocapsules (LNC), were compared to encapsulate NecroX-5 and rapamycin. A magnetic-dependent method was employed to associate SCAP with nanomedicines, involving co-encapsulation of drugs and Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) in the nanocarriers and cell magnetization using Nanoshuttle™. In vivo, SCAP hybrid spheroids expressing Luciferase, when injected subcutaneously into immunocompetent mice, showed increased bioluminescence signals compared to regular spheroids. These results provide proof-of-concept that magnetic-driven association of cells and nanomedicines into hybrid spheroids is feasible and suggest that delivering SCAP as hybrid spheroids can enhance their survival.

Pulpal infections, often caused by bacteria or trauma, can lead to periapical disease. While root canal treatment (RCT) is the standard for addressing these issues, the lack of nutrient supply...

Mesenchymal stem cells (MSCs) are attracting growing interest by the scientific community due to their huge regenerative potential. Thus, the plasticity of MSCs strongly suggests the utilization of these cells for regenerative medicine applications. The main issue about the clinical use of MSCs is related to the complex way to obtain them from healthy tissues; this topic has encouraged scientists to search for novel and more advantageous sources of these cells in easily accessible tissues. The oral cavity hosts several cell populations expressing mesenchymal stem cell like-features, furthermore, the access to oral and dental tissues is simple and isolation of cells is very efficient. Thus, oral-derived stem cells are highly attractive for clinical purposes. In this context, human periapical cyst mesenchymal stem cells (hPCy-MSCs) exhibit characteristics similar to other dental-derived MSCs, including their extensive proliferative potential, cell surface marker profile and the ability to differentiate into various cell types such as osteoblasts, adipocytes and neurons. Importantly, hPCy-MSCs are easily collected from the surgically removed periapical cysts; this reusing of biological waste guarantees a smart source of stem cells without any impact on the surrounding healthy tissues. In this review, we report the most interesting research topics related to hPCy-MSCs with a newsworthy discussion about the future insights. This newly discovered cell population exhibits interesting and valuable potentialities that could be of high impact in the future regenerative medicine applications.

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Smart nanomaterials have emerged as a promising strategy to enhance the therapeutic potential of stem cell based regenerative medicine. Among these, stimuli-responsive nanocarriers offer precise spatiotemporal control over drug delivery and cellular modulation by responding to specific biological or physicochemical triggers such as pH, temperature, enzymes, and redox gradients. These advanced systems improve stem cell homing, survival, differentiation, and immunomodulatory functions while minimizing systemic toxicity. Despite their significant advantages, concerns related to safety, including cytotoxicity, immunogenicity, biodistribution, and long-term toxicity, remain critical barriers to clinical translation. Furthermore, the integration of nanotechnology with stem cell therapy introduces additional complexity in manufacturing, requiring strict adherence to Good Manufacturing Practice (GMP) standards to ensure product quality, reproducibility, and safety. This review critically evaluates the design, mechanisms, efficacy, and safety of responsive nanocarriers for targeted stem cell modulation. It also examines current GMP requirements, regulatory challenges, and translational hurdles associated with these hybrid systems. Finally, future perspectives focusing on scalable manufacturing, standardized regulatory frameworks, and advanced biomimetic nanomaterials are discussed to accelerate clinical adoption.

Dental pulp angiogenesis is a committed step in pulp regeneration therapy, and exosomes provide a new cell-free choice for tissue regeneration. This study revealed the underlying regulatory mechanism of exosomes from stem cells of the apical papilla (SCAPs) under hypoxic state on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. Exosomes extracted from normoxia or hypoxia-pretreated SCAPs were co-cultured with HUVECs, and hypoxia pretreatment increased the release of exosomes and the internalization of exosomes by HUVECs. Compared to normoxic SCAPs-derived exosomes, exosomes from hypoxic SCAPs were found to promote cell proliferation and migration in HUVECs, as it was respectively determined by Cell Counting Kit-8, RT-qPCR and Transwell assay. Besides, hypoxia-educated SCAPs-exosomes especially enhanced the angiogenesis abilities of HUVECs in vitro, which were confirmed by tube formation assay and RT-qPCR detection of angiogenesis-related molecular markers. Interestingly, we found that the hypoxia inducible factor-1α (HIF-1α)/Notch1 signaling pathway was activated in hypoxic SCAPs, and protein jagged-1 (JAG1) was delivered by hypoxic SCAPs-derived exosomes to increase vascular endothelial growth factor (VEGF) production in HUVECs. Moreover, exogenous interference of JAG1 expression in HUVECs partially neutralized the activities of hypoxic SCAPs-exosomes in promoting cell proliferation, migration and tube formation of HUVECs. In summary, this study elucidates that exosomes from hypoxic SCAPs shows high potential to promote angiogenesis in vitro through the HIF-1α/JAG1/VEGF signaling cascade, which may provide a new perspective for the development of vascular reconstruction measures during dental regeneration engineering.

METHODOLOGY This study aims to characterize apical repair dynamics in immature permanent teeth after severe intrusive luxation, and to explore Notch signaling pathway regulation in this process using a Sprague-Dawley rat model. In this study, a modified tool was utilized to establish an intrusive luxation model in SD rats. Tissue repair was assessed via micro-computed tomography (Micro-CT) and hematoxylin-eosin (H&E) staining. Differential gene expression analysis of stem cells from the apical papilla (SCAPs) was performed using the publicly available GEO dataset. Immunohistochemical detection of Notch2 receptor expression in the apical region of injured teeth was subsequently conducted, guided by bioinformatics screening. Finally, the Notch signaling pathway was pharmacologically inhibited using DAPT (γ-secretase inhibitor), and its impact on post-injury prognosis was evaluated. RESULTS Histological analysis revealed prevalent pulp hypoplasia and apical tissue fibrosis after injury. Differential gene analysis suggested that the Notch signaling pathway, particularly Notch2, is involved in the regulation of angiogenesis-related pathways in SCAPs. Immunohistochemistry showed positive Notch2 expression in fibrotic apical regions. Notably, inhibition of Notch signaling significantly reduced aberrant fibrosis while enhancing vascular proliferation in the injury site. CONCLUSIONS Severe intrusive luxation is primarily characterized by aberrant fibrous differentiation in the apical region. The Notch signaling pathway may negatively regulate angiogenesis in the damaged apical area, suggesting that targeted inhibition of this pathway could promote tissue repair following embedded dental injuries.

Introduction Angiogenesis represents a critical challenge in dental pulp regeneration due to the tissue’s restricted nutrient supply through a 0.5-mm apical foramen. While dental pulp stem cells (DPSCs) hold regenerative potential, their limited vascularization capacity impedes clinical applications. Through Single-cell RNA sequencing (scRNA-seq) analysis of human dental pulp, we discovered a PDGF (+) mesenchymal subset exhibiting enhanced angiogenic signatures, suggesting targeted cell selection could overcome this bottleneck. Methods ScRNA-seq identified PDGF (+) subpopulation in human pulp samples, validated through multiplex immunohistochemical of the localization of PDGF/CD73/CD31. PDGF-BB-overexpressing DPSCs were engineered via lentiviral vectors. Functional assessments included: 1) CCK-8/Edu/cell cycle/transwell assays for proliferation and migration ability 2) HUVECs co-culture models analyzing chemotaxis and tube formation 3) Vascularized tissue formation in rat kidney capsule transplants. Results and Discussion The CD73 (+) PDGF (+) subpopulation demonstrated spatial correlation with CD31 (+) vasculature. PDGF-BB overexpression enhanced DPSCs' proliferative capacity and migration capacity. Co-cultured HUVECs exhibited increased tube formation with PDGF-BB group. In vivo transplants generated more vascular structures containing CD31 (+) endothelia. These findings establish PDGF-BB engineering as an effective strategy to amplify DPSCs' angiogenic potential, while emphasizing the therapeutic value of functionally-defined stem cell subpopulations in pulp regeneration.

Major traumatic tissue defects are common clinical problems often complicated by infection and local vascular dysfunction, processes which hinder the healing process. Although local application of growth factors or stem cells through various tissue engineering techniques are promising methods for the repair of tissue defects, limitations in their clinical application exist. Herein, we synthesized multifaceted nanohybrids composed of Quaternized chitosan (QCS), Graphene oxide (GO), and Polydopamine (PDA; QCS-GO-PDA). Covalent grafting of QCS and GO at a mass ratio of 5:1 (5QCS-1GO) displayed excellent biocompatibility and enhanced osteogenic ability, while addition of PDA (5QCS-1GO-PDA) reduced the level of reactive oxygen species (ROS). 5QCS-1GO-PDA was able to achieve wound tissue regeneration by reducing the inflammatory response and enhancing angiogenesis. Furthermore, Polylactic acid/hydroxyapatite (PLA/HA) composite scaffolds were printed using Selective Laser Sintering (SLS) and the hybrid nanomaterial (5QCS-1GO-PDA) was used to coat the PLA/HA scaffold (5QCS-1GO-PDA@PLA/HA) to be used for rapid bone regeneration. 5QCS-1GO-PDA not only improved angiogenesis and osteogenic differentiation, but also induced M2-type polarization of macrophages and promoted bone regeneration via the BMP2/BMPRs/Smads/Runx2 signaling pathway. The bidirectional enhanced healing ability of the multifaceted nanohybrids 5QCS-1GO-PDA provides a promising method of effectively treating tissue defects.

Reconstruction of complex critical-size defects (CSD) in the craniofacial region is a major challenge, and soft tissue regeneration is crucial in determining the therapeutic outcomes of craniofacial CSD. Stem cells from apical papilla (SCAP) are neural crest-derived mesenchymal stem cells (MSCs) that are homologous to cells in craniofacial tissue and represent a promising source for craniofacial tissue regeneration. Exosomes, which contain compound bioactive compounds, are the key factors in stem cell paracrine action. However, the roles of exosomes derived from SCAP (SCAP-Exo) in tissue regeneration are not fully understood. Here, we explored the effects and underlying mechanisms of SCAP-Exo on CSD in maxillofacial soft tissue. SCAP-Exo were isolated and identified by transmission electron microscopy and nanoparticle tracking analysis. The effects of SCAP-Exo on wound healing and vascularization were detected by measuring the wound area and performing histological and immunofluorescence analysis on the palatal gingival CSD of mice. Real-time live-cell imaging and functional assays were used to assess the effects of SCAP-Exo on the biological functions of endothelial cells (ECs). Furthermore, the molecular mechanisms of SCAP-Exo-mediated EC angiogenesis in vitro were tested by immunofluorescence staining, Western blot, and pull-down assays. Finally, in vivo experiments were carried out to verify whether SCAP-Exo could affect vascularization and wound healing through cell division cycle 42 (Cdc42). We found that SCAP-Exo promoted tissue regeneration of palatal gingival CSD by enhancing vascularization in the early phase in vivo and that SCAP-Exo improved the angiogenic capacity of ECs in vitro. Mechanistically, SCAP-Exo elevated cell migration by improving cytoskeletal reorganization of ECs via Cdc42 signalling. Furthermore, we revealed that SCAP-Exo transferred Cdc42 into the cytoplasm of ECs and that the Cdc42 protein could be reused directly by recipient ECs, which resulted in the activation of Cdc42-dependent filopodium formation and elevation in cell migration of ECs. This study demonstrated that SCAP-Exo had a superior effect on angiogenesis and effectively promoted craniofacial soft tissue regeneration. These data provide a new option for SCAP-Exo to be used in a cell-free approach to optimize tissue regeneration in the clinic.

Organ shortages and transplant rejections underscore the urgent need for advanced regenerative solutions. Alginate, a biocompatible polysaccharide from brown algae, is pivotal in tissue engineering due to its tunable gelation and extracellular matrix-mimicking properties. This review explores the synthesis and functionalization of alginate-based biomaterials, which integrate polymers, ceramics, and nanomaterials to enhance cell adhesion, proliferation, and differentiation for bone, cartilage, and soft tissue regeneration. Advanced fabrication techniques, such as 3D/4D bioprinting and microfluidics, achieve precise scaffold architectures, with preclinical outcomes showing significant cell viability and robust tissue integration. Smart alginate hydrogels, responsive to pH, light, temperature, or magnetic stimuli, facilitate controlled release of bioactive molecules promoting angiogenesis. Computational modeling and AI-driven design optimize scaffold performance, predicting drug release kinetics with more accuracy. Despite these advances, challenges such as limited mechanical strength, immune responses, and scalability persist. Future directions focus on personalized scaffolds, sustainable algal sourcing, and scalable bioprinting to accelerate clinical translation. This review highlights the transformative potential of alginate in regenerative medicine, offering insights into advancing smart polysaccharide-based biomaterials.

Currently, the concept of regeneration and regenerative therapies are already being applied clinically to treat pulpal and periodontal diseases, as well as to repair and regenerate systemic organs and tissues. During wound healing, well-developed, functional vascular networks and revascularization are fundamental factors in restoring regenerative potential. Growth factors, stem cells, and scaffolds alone or in combination are reported to contribute to successful tissue repair and engineering via cell transplantation, cell homing or other technologies. Among the growth factors, basic fibroblast growth factor (bFGF) has been found to regulate the proliferation, stemness, migration, and differentiation of vascular and mineralized tissues into various cell types through the differential activation of FGF receptors (FGFRs) and downstream signaling pathways. In addition to growth factors, various dental stem cells are widely used for the regeneration of diseased or lost dental pulp and periodontal tissues, yielding promising results. Stem cells from the apical papilla (SCAPs) and dental pulp stem cells (DPSCs), with or without bFGF, have been shown to be crucial for angiogenesis/revascularization, neuronal growth, and the repair/regeneration of the pulpo-dentin complex, apexogenesis, and may potentially be used in the future to treat various systemic diseases such as myocardial infarction, diabetes, retinopathy, and others. Further studies are needed to optimize the use of bFGF and dental stem cells such as SCAPs and DPSCs by using cell transplantation, cell homing or other technologies for tissue and organ regeneration in experimental animal models and, eventually, in clinical patients in the future.

Periapical periodontitis (AP) is an inflammatory disease caused by persistent endodontic biofilms, and its treatment remains challenging because conventional root canal therapy sometimes fails to achieve effective disinfection and tissue regeneration. Herein, a multifunctional bimetallic ion-modified metal-organic framework (MOF) nanozyme composite, MOF-FeAg-AMP@HA, was engineered for synergistic AP therapy. Incorporation of Fe

Natural bone has a complex hierarchical nanostructure composed of well-organized collagen fibrils embedded with apatite crystallites. Bone tissue engineering requires scaffolds with structural properties and functionality similar to the natural bone. Inspired by bone, a collagen-apatite (Col-Ap) nanocomposite was fabricated with bonelike subfibrillar nanostructures using a modified bottom-up biomimetic approach and has a potential role in the healing of large bone defects in unresolved apical periodontitis. The bone regeneration potential of the Col-Ap nanocomposite was investigated by comparing it with inorganic beta-tricalcium phosphate and organic pure collagen using a critical-sized rodent mandibular defect model. Micro-computed tomographic imaging and histologic staining were used to evaluate new bone formation in vivo. When compared with the beta-tricalcium phosphate and collagen scaffolds, the Col-Ap nanocomposite scaffold exhibited superior regeneration properties characterized by profuse deposition of new bony structures and vascularization at the defect center. Immunohistochemistry showed that the transcription factor osterix and vascular endothelial growth factor receptor 1 were highly expressed in the Col-Ap group. The results indicate that the Col-Ap nanocomposite activates more bone-forming cells and stimulates more vascular tissue ingrowth. Furthermore, the Col-Ap nanocomposite induces extracellular matrix secretion and mineralization of rat bone marrow stem cells. The increased expression of transforming growth factor beta 1 may contribute to the formation of a mineralized extracellular matrix. The present study lays the foundation for the development of Col-Ap nanocomposite-based bone grafts for future clinical applications in bone regeneration of large periapical lesions after apical curettage or apicoectomy.

Apical periodontitis (AP) is a dental-driven condition caused by pathogens and their toxins infecting the inner portion of the tooth (i.e., dental pulp tissue), resulting in inflammation and apical bone resorption affecting 50% of the worldwide population, with more than 15 million root canals performed annually in the United States. Current treatment involves cleaning and decontaminating the infected tissue with chemo-mechanical approaches and materials introduced years ago, such as calcium hydroxide, zinc oxide-eugenol, or even formalin products. Here, we present, for the first time, a nanotherapeutics based on using synthetic high-density lipoprotein (sHDL) as an innovative and safe strategy to manage dental bone inflammation. sHDL application in concentrations ranging from 25 µg to 100 µg/mL decreases nuclear factor Kappa B (NF-κB) activation promoted by an inflammatory stimulus (lipopolysaccharide, LPS). Moreover, sHDL at 500 µg/mL concentration markedly decreases in vitro osteoclastogenesis (P < 0.001), and inhibits IL-1α (P = 0.027), TNF-α (P = 0.004), and IL-6 (P < 0.001) production in an inflammatory state. Notably, sHDL strongly dampens the Toll-Like Receptor signaling pathway facing LPS stimulation, mainly by downregulating at least 3-fold the pro-inflammatory genes, such as Il1b, Il1a, Il6, Ptgs2, and Tnf. In vivo, the lipoprotein nanoparticle applied after NaOCl reduced bone resorption volume to (1.3 ± 0.05) mm

Persistent apical periodontitis is a critical challenge for endodontists. Developing root canal filling materials with continuous antibacterial effects and tightly sealed root canals are essential strategies to avoid the failure of root canal therapy and prevent persistent apical periodontitis. We modified the EndoREZ root canal sealer with the antibacterial material dimethylaminododecyl methacrylate (DMADDM) and magnetic nanoparticles (MNPs). The mechanical properties of the modified root canal sealer were tested. The biocompatibility of this sealer was verified in vitro and in vivo. Multispecies biofilms were constructed to assess the antibacterial effects of the modified root canal sealer. We applied magnetic fields and examined the extent of root canal sealer penetration in vitro and in vivo. The results showed that EndoREZ sealer containing 2.5% DMADDM and 1% MNP had biological safety and apical sealing ability. In addition, the modified sealer could increase the sealer penetration range and exert significant antibacterial effects on multispecies biofilms under an external magnetic field. According to the in vivo study, the apices of the root canals with the sealer containing 2.5% DMADDM and 1% MNP showed no significant resorption and exhibited only a slight increase in the periodontal ligament space, with a good inhibitory effect on persistent apical periodontitis.

Assessment of antibacterial properties of a new intracanal paste based on calcium hydroxocuprate (CHC) and silver nanoparticles hydrosol for passive root impregnation. The study included 55 teeth with 69 root canals belonging patients with chronic apical periodontitis. The main group, including 44 root canals, was filled with a new paste based on CHC and silver nanoparticles for 7 days after preparation and irrigation. In the control group, 25 root canals were sealed with an aqueous paste of calcium hydroxide for 14 days. The presence of the endodontic microorganisms was evaluated by real-time PCR. Further analysis showed that the amount of the DNA, common for These findings suggest that the new method of passive root impregnation with the CHC and silver nanoparticles paste may be an effective method for the treatment of chronical apical periodontitis. Оценка антибактериального потенциала нового противомикробного препарата на основе гидроксокупрата кальция (ГМК) и гидрозоля наночастиц серебра для пассивной импрегнации корня зуба при лечении больных хроническим апикальным периодонтитом. Исследовано 55 зубов, имеющих 69 корневых каналов. Из них 44 корневых канала (основная группа) после механической и медикаментозной обработки заполняли новым препаратом на основе ГМК и гидрозоля наночастиц серебра на 7 дней. В контрольной группе 25 корневых каналов пломбировали водной пастой гидроксида кальция на срок 14 дней. Состав микрофлоры, выделенной из корневых каналов зубов, оценивали методом полимеразной цепной реакции (ПЦР) в реальном времени. При повторном исследовании микрофлоры (после обработки каналов) в основной группе было зарегистрировано значительно меньшее количество ДНК Метод пассивной наноимпрегнации дентина корня зуба новым препаратом на основе ГМК и гидрозоля наночастиц серебра продемонстрировал выраженный бактериостатический потенциал по отношению к микроорганизмам, ассоциированным с периапикальным воспалительным процессом.

Refractory apical periodontitis (RAP) is an endodontic apical inflammatory disease caused by

The main issues faced during the treatment of apical periodontitis are the management of bacterial infection and the facilitation of the repair of alveolar bone defects to shorten disease duration. Conventional root canal irrigants are limited in their efficacy and are associated with several side effects. This study introduces a synergistic therapy based on nitric oxide (NO) and antimicrobial photodynamic therapy (aPDT) for the treatment of apical periodontitis. This research developed a multifunctional nanoparticle, CGP, utilizing guanidinylated poly (ethylene glycol)-poly (ε-Caprolactone) polymer as a carrier, internally loaded with the photosensitizer chlorin e6. During root canal irrigation, the guanidino groups on the surface of CGP enabled effective biofilm penetration. These groups undergo oxidation by hydrogen peroxide in the aPDT process, triggering the release of NO without hindering the production of singlet oxygen. The generated NO significantly enhanced the antimicrobial capability and biofilm eradication efficacy of aPDT. Furthermore, CGP not only outperforms conventional aPDT in eradicating biofilms but also effectively promotes the repair of alveolar bone defects post-eradication. Importantly, our findings reveal that CGP exhibits significantly higher biosafety compared to sodium hypochlorite, alongside superior therapeutic efficacy in a rat model of apical periodontitis. This study demonstrates that CGP, an effective root irrigation system based on aPDT and NO, has a promising application in root canal therapy.

To evaluate histologically and radiographically the potential of dog's immature roots with apical periodontitis to regenerate after regenerative endodontic treatment using mesoporous silica nanoparticles (MSNs) with/without bone morphogenic protein (BMP-2) as scaffolds. In 4 mongrel dogs, 56 immature teeth with 96 roots were infected, resulting in necrotic pulps and periapical pathosis. According to the evaluation time (Group I = 30 days and Group II = 90 days), 90 roots were divided into two equal groups (45 roots each) and 6 roots used to replace any lost root during the procedure. The two main groups were further divided according to treatment protocol into 5 subgroups (9 roots each): blood clot (BC subgroup), mesoporous silica nanoparticles scaffold only (MSNs subgroup), mesoporous silica nanoparticles impregnated with BMP2 (MSNs + BMP2 subgroup), infected teeth without treatment (+ ve control subgroup) and normal untouched teeth (-ve control subgroup). All teeth surfaces were coated with Tincture iodine and calcium hydroxide was applied prior to treatment protocols. Then, teeth were restored with glass ionomer filling to seal the remaining part of the access cavity. Radiography evaluation of the increase in root length, root thickness and occurrence of apical closure were performed. Following the sacrifice of the two dogs at each time of evaluation, histopathological analysis was performed and included the inflammatory cells count, bone resorption, tissue ingrowth, deposition of hard tissue, and closure of the apical part. All data were statistically analyzed. Compared to BC subgroup, MSNs and MSNs + BMP-2 subgroups exhibited significant higher increase in root length and thickness as well as higher vital tissue in-growth and new hard tissue formation in group II (P < 0.05). MSNs + BMP-2 subgroup had significant higher increase in root length and thickness as well as significant lower inflammatory cell count than MSNs subgroup in both groups (P < 0.05). There were no significant differences between MSNs and MSNs + BMP-2 subgroups regarding new hard tissue formation in both groups and apical closure in group I (P > 0.05). MSNs with/without BMP-2 scaffolds enabled the continuing growth of roots in immature teeth with necrotic pulps and periapical pathosis. Addition of BMP-2 to MSNs scaffold improved its outcome in regenerative endodontics. MSNs with/without BMP-2 scaffolds may alternate blood clot for regenerative endodontic treatment of immature teeth with necrotic pulps.

The purpose of this study is to investigate the influence of nano-hydroxyapatite (nano-HA) filling on the restoration of masticatory function and the modulation of inflammatory factors within gingival sulcular fluid in patients suffering from periapical inflammation. 98 patients with periapical inflammation were selected and divided into a control group and a nano group using the red blue ball method, with 49 cases in each group. The control group was treated with conventional root canal therapy only, and the nano group underwent endodontic treatment with the nano-HA filling method. Gingival fluid samples were collected from all patients at enrollment, 1 week, and 3 months postoperatively to analyze the levels of interleukin- 1β (IL- 1β) and tumor necrosis factor-α (TNF-α). At the time of enrollment and 3 months after surgery, patients were monitored for bite force, masticatory efficiency, and clinical efficacy. In this study, compared to the control group, the experimental group treated with nano-HA filling showed significantly better improvement in bite force and masticatory efficiency, with the difference being statistically significant (P < 0.01). Moreover, the experimental group significantly inhibited the expression of inflammatory factors such as IL- 1β and TNF-α, with a continuous decrease in their levels over time. In terms of filling effect, healing rate, and total efficacy rate, the experimental group also achieved superior results compared to the control group, with the difference being statistically significant (P < 0.05). There was a negative correlation between the application of nano-HA fillers and the gingival sulcus inflammatory factor at 1 week postoperatively and 3 months postoperatively. In comparison with conventional restorative materials, nano-HA restorative has been shown to possess several notable advantages. These include the promotion of recovery of masticatory function, the regulation of inflammatory factor expression in gingival sulcular fluid, and the enhancement of clinical efficacy and filling effect. This study provides a theoretical basis for the clinical promotion of the use of nano-HA restorative materials in the treatment of periapical inflammation.

Endodontics uses cell therapy strategies to treat pulpal and periapical diseases. During these therapies, surgeons aim to reconstruct the natural microenvironments that regulate the activity of dental stem cells. We searched for more than 400 articles in PubMed using key words from regenerative endodontics and dental stem cell biology. In 268 articles, we reviewed what factors may influence histologic results after preclinical dental treatments that use regenerative endodontic procedures after pulpectomy. Several factors, such as the origin of stem cells, the biomimicry of scaffolds used, and the size of lesions, are considered to influence the histologic appearance of the regenerated pulp-dentin complex after treatments. Information is accumulating on transcription factors that generate the pulp-dentin complex and survival/trophic factors that would benefit niche recovery and histologic results. In this article, we discuss the noninterchangeability of stem cells, the influence of dentin-entrapped molecule release on pulp regeneration and survival of stem cells, and the need of positional markers to assess treatments histologically. The ex vivo amplification of appropriate dental stem cells, the search for scaffolds storing the molecular diversity entrapped in the dentin, and the use of positional transcription factors as histologic markers are necessary to improve future preclinical experiments.

Nonsurgical local treatment of a periapical lesion arising from trauma or bacterial infection is a promising innovative approach. The present study investigated the feasibility of developing injectable amorphous calcium phosphate nanoparticles (ACP NPs) and ACP NPs loaded with an anti-inflammatory drug; ibuprofen (IBU-ACP NPs) in the form of thermoreversible in situ gels to treat periapical lesions with the stimulation of bone formation. NPs were produced by a spray-drying technique. Different formulations of Poloxamer 407 were incorporated with/without the produced NPs to form injectable gels. A drug release study was carried out. A 3 month in vivo test on a dog model also was assessed. Results showed successful incorporation of the drug into the NPs of CP during spray drying. The particles had mean diameters varying from 100 to 200 nm with a narrow distribution. A drug release study demonstrated controlled IBU release from IBU-ACP NPs at a pH of 7.4 over 24 h. The gelation temperature of the injectable in situ gels based on Poloxamer 407 was measured to be 30 °C. After 3 months of implantation in dogs, the results clearly demonstrated that the inclusion of ACP NPs loaded with IBU showed high degrees of periapical bone healing and cementum layer deposition around the apical root tip.

Prolonged or excessive inflammation may lead to impaired vascularization and bone regeneration, hindering the normal repair process of bone tissue. Although the regulation of inflammation is crucial for promoting a conducive microenvironment for bone regeneration, individual anti-inflammatory interventions frequently are inadequate in facilitating effective bone repair. Here, a multifunctional hydrogel (GelMA-ZC-Yoda1) with multifaceted therapeutic strategy was designed by integrating Zinc/Cerium-layered double oxide nanozyme (ZnCe-LDO, with catalase-like activity) and Yoda1 (an activator of the mechanically sensitive Piezo1 ion channel) into photocurable GelMA hydrogel. The ZnCe-LDO nanozyme in the hydrogel promoted M2 macrophage polarization by reprogramming inflammatory macrophages, establishing a favorable microenvironment, while the sustained release of zinc and cerium ions facilitated osteo/angiogenesis. Additionally, the Yoda1 released from the hydrogel chemically simulated a mechanical signal to activate the Piezo1 channel, regulating osteo/angiogenesis via the Piezo1/YAP1 signaling pathway.

Effective infection control without irritating the pulp tissue is the key to successful vital pulp therapy. Developing a novel antibacterial biomaterial that promotes dentin regeneration for pulp capping is thus a promising strategy for enhancing vital pulp therapy. Lithium-doped mesoporous nanoparticles (Li-MNPs) were synthesized using an alkali-catalyzed sol-gel method. The particle size, elemental distribution, surface morphology, pore structure, and ion release from Li-MNPs were measured. Human dental pulp stem cells (hDPSCs) and Li-MNPs had a larger surface area (221.18 m Li-MNPs promoted dentin regeneration and inhibited

In recent years, nanomaterials have been increasingly developed and applied in the field of bone tissue engineering. However, there are few studies on the induction of bone regeneration by tantalum nanoparticles (Ta NPs) and no reports on the effects of Ta NPs on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and the underlying mechanisms. The main purpose of this study was to investigate the effects of Ta NPs on bone regeneration and BMSC osteogenic differentiation and the underlying mechanisms. The effects of Ta NPs on bone regeneration were evaluated in an animal experiment, and the effects of Ta NPs on osteogenic differentiation of BMSCs and the underlying mechanisms were evaluated in cell experiments. In the animal experiment, hematoxylin-eosin (HE) staining and hard-tissue section analysis showed that Ta NPs promoted bone regeneration, and immunohistochemistry revealed elevated expression of BMP2 and Smad4 in cells cultured with Ta NPs. The results of the cell experiments showed that Ta NPs promoted BMSC proliferation, alkaline phosphatase (ALP) activity, BMP2 secretion and extracellular matrix (ECM) mineralization, and the expression of related osteogenic genes and proteins (especially BMP2, Smad4 and Runx2) was upregulated under culture with Ta NPs. Smad4 expression, ALP activity, ECM mineralization, and osteogenesis-related gene and protein expression decreased after inhibiting Smad4. These data suggest that Ta NPs have an osteogenic effect and induce bone regeneration by activating the BMP2/Smad4/Runx2 signaling pathway, which in turn causes BMSCs to undergo osteogenic differentiation. This study provides insight into the molecular mechanisms underlying the effects of Ta NPs in bone regeneration.

This study aimed to determine the impact of human endometrial stem cells (EnSCs) and titanium oxide nanoparticles (TiO

Previous studies have shown the important relationships between Enterococcus faecalis and Candida albicans in post-treatment endodontic disease (PTED). However, the fungal-bacterial interactions and their possible functional routes are less understood. In this study, we investigated the effect of extracellular vesicles (EVs) derived from C. albicans on E. faecalis growth and pathogenicity. Candida albicans EVs were isolated from a yeast nitrogen base (YNB) medium, and their morphology, size distribution, and protein concentration were observed and identified. The effects of EVs on planktonic E. faecalis were evaluated using growth curves and colony-forming unit counts, whereas the effects on E. faecalis biofilms were determined using scanning electron and confocal laser scanning microscopes. The ability of E. faecalis to resist a detrimental environment, infect dentinal tubules, and biofilm formation on gutta percha was examined. Additionally, the effect of EVs on cell invasion and cytotoxicity of E. faecalis were assessed. Statistical analysis was performed using one-way analysis of variance, and p-values of <.05 were considered significantly different. Candida albicans EVs were nanoparticles with bilayer membranes and with peak sizes of 111.9 and 230 nm. EVs exhibited a complex effect on E. faecalis and its biofilms; 5 μg/mL of EVs showed inhibitory effects whereas 0.156 μg/mL of EVs facilitated their growth. The EVs showed consistent effects on E. faecalis virulence. Notably, 5 μg/mL of EVs reduced the damage to RAW264.7 cells caused by E. faecalis, as well as the invasion ability of E. faecalis to macrophages and the intracellular survival ability of E. faecalis after macrophage phagocytosis, whereas 0.156 μg/mL of EVs had completely opposite effects. Candida albicans EVs showed dual effects on E. faecalis growth and virulence in vitro, suggesting C. albicans EVs are involved in fungal-bacterial communication. Moreover, the inhibitory effects exhibited by 5 μg/mL of EVs in vitro may suggest a new agent for the control of E. faecalis.

Reparative tertiary dentinogenesis requires the recruitment and odontogenic differentiation of dental pulp stem cells (DPSCs). Extracellular vesicles (EVs) as bioactive molecules have gained attention in regenerative medicine for their ability to mediate tissue repair through intercellular communication, influencing cell recruitment, proliferation, and differentiation. This study aimed to evaluate the effects of EVs on DPSC homing and odontogenic differentiation for dentin regeneration. DPSC-derived EVs were cultured in either growth (EV-G) or odontogenic differentiation (EV-O) conditions and isolated using a modified precipitation method. EVs were characterized by nanoparticle tracking analysis, scanning electron microscopy, antibody array, and cellular uptake assay. Treatment with 5 × 10

Periodontal infection is a long-lasting inflammatory condition caused by the growth and development of an abnormal and harmful community of microorganisms. This destructive illness leads to the loss of the tissues that support the teeth, degradation of the bone surrounding the teeth, and eventually tooth loss. To treat oral infections, it is necessary to use nonsurgical methods such as antibiotics. However, the indiscriminate and incorrect use of antibiotics results in drug resistance. Among these alternate therapeutic options, using nanoparticles to treat infectious dental disease was particularly significant. Consequently, researchers have worked to develop an effective and satisfactory drug delivery method for treating periodontal and dental illnesses. Albumin nanoparticles serve a considerable function as carriers in the drug delivery of chemical and biomolecular medications, such as anticancer treatments; they have several advantages, including biocompatibility and biodegradability, and they are well-tolerated with no adverse effects. Albumin nanoparticles have several benefits over other nanomaterials. Protein nanocarriers provide advantages such as biocompatibility, biodegradability, reduced immunogenicity, and lower cytotoxicity. Furthermore, this nanoparticle demonstrated significant intrinsic antibacterial properties without being loaded with antibiotic medicines. As a medication and antibacterial nanoparticle delivery method, albumin nanoparticles have substantial applications in periodontal and dental infectious disorders such as periodontal infection, apical periodontitis, and peri-implantitis. As a result, in this article, we studied the usage of albumin nanoparticles in dental disorders.

This study aimed to modify EndoREZ with 2.5% dimethylaminododecyl methacrylate (DMADDM) and 1% magnetic nanoparticles (MNP) to study its sealing property, penetration and long-term antibacterial and therapeutic effect in the single-cone technique (SCT) compared with EndoREZ and iRoot SP. Thirty single-root human maxillary premolars were assigned into three groups and obturated with three different root canal sealers by SCT. Every specimen was then scanned using micro-CT to analyze void fraction, and void volumes and confocal laser scanning microscope (CLSM) was used to study the dentin penetration. The long-term antimicrobial effects were tested in vitro before and after aging 1 and 4 weeks by the single-strain Enterococcus faecalis biofilm model. In addition, the beagle canine model of apical periodontitis (AP) was utilized to judge and compare the therapeutic effect of three sealers in SCT. The void fraction and void volumes of the modified root canal sealer were not significantly different from iRoot SP (p > 0.05) but were lower than EndoREZ (p < 0.05). The modified root canal sealant displayed a greater penetration, long-term antibacterial property, and treatment effect than the other groups (p < 0.05). This indicated that after being modified with DMADDM and MNP, it showed better performance in SCT.

Apical periodontitis, an inflammatory lesion causing bone resorption around the apex of teeth, is treated by eradicating infectious bacteria from the root canal. However, it has a high recurrence rate and often requires retreatment. We investigated the bactericidal effect of antimicrobial photodynamic therapy (aPDT)/photodynamic antimicrobial chemotherapy (PACT) using indocyanine green (ICG)-loaded nanospheres coated with chitosan and a diode laser on a biofilm of

Apical periodontitis (AP) is a prevalent oral disease characterized by periapical tissue inflammation and alveolar bone resorption. This study investigated the inhibitory effects of human exfoliated deciduous teeth-derived exosomes (SHED-EXOs) on osteoclastogenesis, elucidated the underlying mechanisms, and evaluated their protect efficacy in AP rat models, aiming to provide novel adjunctive therapies to augment root canal treatment. In vitro, bone marrow-derived monocytes (BMMs) underwent osteoclastogenesis were cultured with graded concentrations of SHED-EXOs (0-20 μg/mL). Tartrate-resistant acid phosphatase staining and podosome belt immunofluorescence assays were performed to assess osteoclast formation. Osteoclast-related protein and gene expression were quantified. Exosomal proteomics and osteoclast transcriptomic sequencing were integrated with bioinformatic analysis to identify pivotal signalling pathways. In vivo, AP rat model were developed and received localized intrapulpal delivery of hydrogel-encapsulated SHED-EXOs. The therapeutic efficacy was evaluated through micro-CT, histological staining, and immunohistochemical analysis. SHED-EXOs concentration-dependently suppressed osteoclast formation with downregulation of NFATC1/CTSK/RANKL. Multiomics analysis revealed enrichment of PI3K-AKT signalling, and mechanistically, SHED-EXOs may inhibit osteoclastogenesis by activating PI3K-AKT pathway. In vivo, local delivery of SHED-EXOs via hydrogel significantly reduced the number of osteoclasts, decreased the expression of NFATC1 as well as RANKL, activated PI3K-AKT signalling, attenuated bone resorption, and restored periapical structure. SHED-EXOs may serve as a promising cell-free adjunctive strategy for AP, inhibiting osteoclasts potentially via PI3K-AKT activation. This study developed a novel cell-free therapeutic strategy based on SHED-EXOs to enhance the treatment efficacy for AP. SHED-EXOs effectively inhibit osteoclast activity, attenuate bone resorption, and promote periapical bone tissue repair. The underlying mechanism involves the activation of the PI3K-AKT pathway. Combined with a localized hydrogel delivery system, this strategy paves the way for innovative approaches in regenerative endodontics.

Achieving functional tissue regeneration hinges on the coordinated growth of intricate blood vessels and nerves within the defect area. However, current strategies do not offer a reliable and effective way to fulfill this critical need. To address this challenge, a three-dimensional (3D) gelatin methacryloyl-multi-walled carbon nanotube/cobalt (GelMA-MWCNTs/Co) hydrogel with controlled release of cobalt (Co) ions was developed for hypoxia-mimicking and dual beneficial effects on promoting vasculogenesis and neurogenesis. GelMA-MWCNTs/Co hydrogel exhibited sustained release of Co ions, promoting laden cell viability and long-term cell survival. GelMA-MWCNTs/Co hydrogel effectively enhanced human umbilical vein endothelial cells (HUVECs) vasculogenesis when cocultured with stem cells from apical papilla (SCAP). Moreover, this hydrogel facilitated the interaction between the pre-formed vascular and neural-like structures generated by electrical stimulation-induced SCAP (iSCAP). Furthermore, our in vivo study revealed that the GelMA-MWCNTs/Co hydrogel remarkably enhanced neovascularization and accelerated anastomosis with the host vasculature. The pre-vascularized scaffolds boosted the presence of neural differentiated SCAP in the regenerated tissue. This study provided proof of integrating functional Co ions release materials and dental-derived stem cells within a hydrogel scaffold as a promising potential for achieving simultaneous vascularization and neurogenesis.

The reconstruction of bone defects remains a major clinical issue. Our study aims to investigate the ability of RATEA16 (RA, [CH3CONH] RADARADARADARADA-[CONH2]) for the sustained delivering VEGF and BMP-2 to promote angiogenesis and osteogenesis in bone reconstruction. We prepared and investigated the characterization of RATEA16. The survival of human umbilical vein endothelial cells (HUVECs) and human stem cells of the apical papilla (SCAPs) encapsulated in RATEA16 hydrogel was detected. Then, we established RA-VEGF/BMP-2 drug delivery systems and measured their drug release pattern. The effects of RA-VEGF scaffolds on HUVECs angiogenesis were investigated in vitro. Then, osteoblastic differentiation capacity of SCAPs with RA-BMP-2 scaffolds was analyzed by ALP activity and expression of osteoblast-related genes. A porous nanofiber microstructure endowed this scaffold with the ability to maintain the survival of HUVECs and SCAPs. The RA-VEGF/BMP-2 drug delivery systems exhibited several advantagesin vitro: injectability, biodegradability, good biocompatibility, and noncytotoxicity. Released rhVEGF RATEA16 loading with VEGF and BMP-2 might be a potential clinical strategy for tissue engineering, especially in bone reconstruction, due to its ability of delivering growth factors effectively and efficiently.

Bioengineered soft tissues on any meaningful scale or complexity must incorporate aspects of the functional tissue, namely a vasculature, providing cells oxygen and nutrients critical for their survival. However, the ability of tissue engineering strategies to promote a fast revascularization is critically limited. Particularly in endodontic regenerative therapies, the complicated anatomy of the root canal system, and the narrow apical access limit the supply of new blood vessels and pulp tissue ingrowth. Here we characterize the viscoelastic and microstructural properties of a class of injectable hyaluronic acid (HA) hydrogels formed in situ, reinforced with cellulose nanocrystals (CNCs) and enriched with platelet lysate (PL), and test its ability to promote cells recruitment and proangiogenic activity in vitro. The incorporation of CNCs enhanced the stability of the materials against hydrolytic and enzymatic degradation. Moreover, the release of the chemotactic and pro-angiogenic growth factors (GFs) (PDGF and VEGF) from the PL-laden hydrogels showed an improved sustained profile proportional to the amount of incorporated CNCs. The PL-laden hydrogels exhibited preferential supportive properties of encapsulated human dental pulp cells (hDPCs) in in vitro culture conditions. Finally, PL-laden hydrogels stimulated chemotactic and pro-angiogenic activity by promoting hDPCs recruitment and cell sprouting in hDPCs/human umbilical vein endothelial cell co-cultures in vitro, and in an ex vivo model. These results support the use of the combined system as a scaffold for GFs delivery and cells recruitment, thereby exhibiting great clinical potential in treating injuries in vascularized tissues. Innovative strategies for improved chemotactic and pro-angiogenic features of TE constructs are needed. In this study, we developed an injectable HA/CNC/PL hydrogel with improved structural and biologic properties, that not only provide a sustained release of chemotactic and proangiogenic GFs from PL but also enhance the cells' viability and angiogenic activity. As a result of their unique traits, the developed hydrogels are ideally suited to simultaneously act as a GFs controlled delivery system and as a supportive matrix for cell culture, recruitment, and revascularization induction, holding great potential for the regeneration of vascularized soft tissues, such as the dentin-pulp complex.

While pulp regeneration using tissue engineering strategy has been explored for over a decade, successful regeneration of pulp tissues in a full-length human root with a one-end seal that truly simulates clinical endodontic treatment has not been achieved. To address this challenge, we designed and synthesized a unique hierarchical growth factor-loaded nanofibrous microsphere scaffolding system. In this system, vascular endothelial growth factor (VEGF) binds with heparin and is encapsulated in heparin-conjugated gelatin nanospheres, which are further immobilized in the nanofibers of an injectable poly(l-lactic acid) (PLLA) microsphere. This hierarchical microsphere system not only protects the VEGF from denaturation and degradation, but also provides excellent control of its sustained release. In addition, the nanofibrous PLLA microsphere integrates the extracellular matrix-mimicking architecture with a highly porous injectable form, efficiently accommodating dental pulp stem cells (DPSCs) and supporting their proliferation and pulp tissue formation. Our in vivo study showed the successful regeneration of pulp-like tissues that fulfilled the entire apical and middle thirds and reached the coronal third of the full-length root canal. In addition, a large number of blood vessels were regenerated throughout the canal. For the first time, our work demonstrates the success of pulp tissue regeneration in a full-length root canal, making it a significant step toward regenerative endodontics. The regeneration of pulp tissues in a full-length tooth root canal has been one of the greatest challenges in the field of regenerative endodontics, and one of the biggest barriers for its clinical application. In this study, we developed a unique approach to tackle this challenge, and for the first time, we successfully regenerated living pulp tissues in a full-length root canal, making it a significant step toward regenerative endodontics. This study will make positive scientific impact and interest the broad and multidisciplinary readership in the dental biomaterials and craniofacial tissue engineering community.

Adequate and timely vascularization is crucial for the success of dental pulp tissue engineering. Hypoxia, an important driving force of angiogenesis, plays an important role in this process. However, few studies have investigated the fabrication of hypoxia-simulating biomaterials for dental applications. In this study, a novel hypoxia-mimicking, multi-walled carbon nanotubes/cobalt (MWCNTs/Co) nanocomposite was prepared using the metal-organic framework (MOF) route for the in situ insertion of MWCNTs into Co