可降解锌金属表面改性综述：无机、有机及无机-有机复合涂层的背景、种类、特点、现状、列表对比与研究案例

… degradation rate of Zn alloys, shortening the implantation period under … An ideal surface modification should slow down Zn … of biodegradable Zn have been enhanced through surface …

Zinc (Zn)-based biodegradable implants hold great promise for orthopedic applications, yet their clinical translation is hampered by uncontrollable corrosion leading to Zn2+ release at potentially toxic levels in the early stage and insufficient osteogenic stimulation later. Herein, a near-infrared (NIR)-responsive hybrid coating composed of indocyanine green-loaded zeolitic imidazolate framework-8 (ICG@ZIF-8) and polycaprolactone (PCL) is engineered on a Zn-Li-Mg alloy to achieve stage-adaptive corrosion regulation. Initially, the PCL barrier effectively slows down corrosion (∼3.84 μm yr-1) and Zn2+ release, ensuring initial biocompatibility. Upon NIR irradiation, photothermal conversion of ICG@ZIF-8 induces localized heating and PCL deformation, on-demand partially restoring corrosion (∼8.53 μm yr-1) and enabling sustained Zn2+ release to leverage its osteogenic effect. In vitro studies demonstrate enhanced osteogenic differentiation and mineralization, mechanistically attributed to the activation of the Wnt/β-catenin/TCF pathway. In vivo, the NIR-triggered platform promotes critical-sized femoral defect regeneration with 26% higher new bone formation. This work provides a smart material strategy for spatiotemporal control of biodegradable Zn implants, offering a promising strategy toward bone repair.

Zinc is becoming one of the leading candidate materials for biodegradable orthopedic implants owing to its attractive properties in terms of degradation behavior and mechanical properties. However, the insufficient surface bio-activities postpone its clinical application. In this study, an organic-inorganic collagen entrapped calcium/zinc phosphates coating was constructed on Zn surface to lessen Zn2+ releasing rate and to leverage the surface osteogenic and angiogenic properties. Collagen molecules were immobilized onto Zn substrate and subsequently coordinated with calcium and zinc ions to promote the CaZnP inorganic phase growth, ensuing an intertwined collagen-CaZnP hybrid system. Consequently, the hybrid coating was highly coalesced and compact. Such high quality warranted the contained Zn2+ releasing in a tolerable rate favorable for cells viability. The collagen-CaZnP coated Zn showed remarkedly stronger osteogenicity as compared to the untreated Zn, ascertained by the MC3T3-E1 osteoblast cell proliferation and differentiation assays, such as alkaline phosphatase expression and calcium nodule formation results. In addition, this hybrid coating supported human umbilical vein endothelial cells (HUVECs) migration and tube formation. The enhanced osteogenic and angiogenic properties could be ascribed to the nature of collagen and calcium/zinc phosphate components, the hybrid micro/nano-structure as well as the ability of controlling the Zn2+ release of Zn substrate into a suitable concentration range. Our strategy provides a new avenue to surface modification of biodegradable metals for bone regenerative perspective.

Additively manufactured biodegradable zinc (Zn) scaffolds have great potential to repair infected bone defects due to their osteogenic and antibacterial properties. However, the enhancement of antibacterial properties depends on a high concentration of dissolved Zn2+, which in return deteriorates osteogenic activity. In this study, a vancomycin (Van)-loaded polydopamine (PDA) coating was prepared on pure Zn porous scaffolds to solve the above dilemma. Compared with pure Zn scaffolds according to comprehensive in vitro tests, the PDA coating resulted in a slow degradation and inhibited the excessive release of Zn2+ at the early stage, thus improving cytocompatibility and osteogenic activity. Meanwhile, the addition of Van drug substantially suppressed the attachment and proliferation of S. aureus and E. coli bacterial. Furthermore, in vivo implantation confirmed the simultaneously improved osteogenic and antibacterial functions by using the pure Zn scaffolds with Van-loaded PDA coating. Therefore, it is promising to employ biodegradable Zn porous scaffolds with the proposed drug-loaded coating for the treatment of infected bone defects.

… Moreover, the released excessive Zn 2+ will lead to cytotoxicity. In … Zn scaffolds modified with polylactic acid (PLA) coating (PLA/Zn) were fabricated by ultrasonic infiltration of porous Zn …

Percutaneous coronary intervention is widely used as a primary treatment for cardiovascular diseases. In this regard, it has been revealed from studies that zinc is a potential material for use in stents due to its intrinsic physiological relevance, biocompatibility, biodegradability, and pro-regeneration properties. However, localized corrosion and burst release of zinc ions might cause an early implant failure and a risky environment for vascular remodeling. To resolve these drawbacks effectively, a coating of zinc phosphate on pure zinc was fabricated in this study using a microwave-assisted chemical conversion method. In this study, a comprehensive analysis was conducted through materials characterization, electrochemical testing, immersion testing, in vitro testing, and hemocompatibility evaluation to quantify the effect of zinc phosphate coating on zinc cardiovascular stents. It is revealed that the microstructures of the coatings are mainly composed of zinc phosphate and sodium zinc phosphate. The presence of sodium zinc phosphate could improve corrosion behavior. The assessment of in vitro biocompatibility for the zinc phosphate coatings revealed satisfactory cell viability and a stable and smooth degradation surface for cell adhesion. Furthermore, the zinc phosphate coatings exhibited nonhemolytic properties and inhibitions to the adhesion of platelets. The zinc phosphate coatings could exhibit a uniform degradation behavior and a positive biological effect on vascular remodeling, and therefore, these coatings could be a promising surface treatment used in stent optimization for zinc.

Abstract An alendronate (AL)-embedded zinc phosphate (ZnP) coating was synthesized on biodegradable Zn to control its corrosion and long-term degradation while maintaining its bio-functionality. The AL molecules were well incorporated into the ZnP and the hybrid coating was homogeneously compact and dense. The coating not only reduced the corrosion current density and the Zn2+ release rate, but also ensured a uniform long-term degradation behavior of Zn in PBS. The coating retained a desirable balanced osteo-functionality of pro-osteoblast and anti-osteoclast response. The above achieved performance can be credited to the nature of the organic-inorganic components of this coating and its high quality.

The integration of bio‐adaptable performance, elaborate structure, and biological functionality for degradable bone implants is crucial in harnessing the body's regenerative potential to remold load‐bearing bone defects. Herein, material–structure–function integrated additive manufacturing (MSFI‐AM) is deployed to innovate novel zinc‐based bone implants, namely Zn–Mg–Cu alloy. In situ alloying of AM and boundary engineering strategy yield prominent mechanical properties, and the degradation products enable a mechanical self‐strengthened effect, thus coordinating mechanical degeneration and promoting mechanical adaptability. In addition, MSFI‐oriented Zn alloy implants successfully manifest in situ multifunctions of augmenting osteogenesis, immunoregulation, angiogenesis, and anti‐infective activity in vitro and expediting bone ingrowth and regeneration in vivo through the sustained release of divalent metal cations and triply periodic minimal surface (TPMS) structure construction. Overall, MSFI‐AMed Zn alloy implants signify promising clinical translation prospects for load‐bearing applications, and an integrated approach is proposed to endow degradable bone implants with boosted bio‐adaptable performance and in situ bio‐multifunctions.

ABSTRACT Biodegradable implant researches are enhancing nowadays, enduring challenges in programmed degradability and cytocompatibility with connecting tissues. These materials used to implanted, proliferate cellular interaction, degrade and replaced by regenerated natural bone in the living bodies. Distinctive metallic, ceramic and polymer materials were considered and found compatible, enhancing osteoblast and cellular response. Apart from magnesium, zinc and iron metals, alloys and composites are consistent due to their high load-bearing capability, controlled degradation and promising designed biomechanical properties. The properties of various degradable and non-degradable materials are studied here and compared with developed samples’ biomechanical properties. The samples are prepared and fabricated using casting techniques and examined using tensile, compression, hardness and cellular tests. The results are found similar, thus concluded with comparable in-vivo results of previous researchers. Mg.Li and (Zn.Mg).Mn composition is found cytocompatible with programmable biomechanical properties, able to replace Ti-based alloys.

… Therefore, recent attention has been paid on the design, fabrication, and clinical translation of Zn-… of utilizing biodegradable Zn-based alloys as orthopedic internal fixation implants. …

Abstract As advancements in medical technology continue to evolve, the demand for innovative implant materials has become increasingly vital for enhancing overall experience of patients. Traditional non-biodegradable implants, while effective, often necessitate removal through invasive and costly surgical interventions, leading to significant clinical challenges. To address these issues, the development of biodegradable materials has gained prominence due to their ability to gradually degrade and be absorbed by the body, presenting a compelling alternative to permanent implants. This review examines both biodegradable and non-biodegradable metallic implants, focusing on key aspects such as biocompatibility, mechanical properties, and degradation kinetics. Furthermore, it explores the applications of these materials across various medical fields, emphasizing their potential to improve patient care. This review aims to bridge the gap between laboratory innovations, clinical practices, and industrial applications by summarizing current research. It offers valuable insights for researchers, clinicians, and industry professionals, contributing to the ongoing dialogue regarding the future of implant technology and advancing the understanding of material selection for diverse medical applications.

Biodegradable Zn‐based metals have recently gained great attention for orthopedic implant applications, due to their attractive attributes in biodegradability, mechanics, and bio‐functionalities. However, Zn‐based metals suffer from excessive Zn2+ release leading to bio‐incompatibility and insufficient osteogenic properties. Herein, bioactive molecules incorporated zinc phosphate (ZnP) of metal–organic/inorganic hybrid coatings are constructed on Zn surfaces by dip‐coating, targeting a decrease in Zn2+ release rate and an improvement in biocompatible and osteogenic properties. The bioactive molecules, cysteine, phenylalanine, and bovine serum albumin, are incorporated into inorganic ZnP using a metal–organic/inorganic coordination strategy. As a result, these hybrid coatings are compact, and present different micro/nanostructured surface morphology. The electrochemical and long‐term static immersion results show that the hybrid coatings decrease the corrosion rate of Zn, reduce the Zn2+ ion release rate, and promote hydroxyapatite deposition. In addition, they promote the proliferation and adhesion of preosteoblast MC3T3‐E1 and rat bone marrow mesenchymal stem cells, and up‐regulate the expression of osteogenesis‐related genes. Such appealing properties can be attributed to the characteristic micro/nanostructured surface morphologies and the presence of the bioactive components. These metal–organic/inorganic hybrid coatings provide a novel avenue to modify the surface of Zn‐based metals for orthopedic implant applications.

… of the research on Zn-based biodegradable materials. Numerous innovative Zn-based biodegradable alloys created recently are assessed for their biodegradability, biocompatibility, …

Metallic materials such as stainless steel (SS), titanium (Ti), magnesium (Mg) alloys, and cobalt-chromium (Co-Cr) alloys are widely used as biomaterials for implant applications. Metallic implants sometimes fail in surgeries due to inadequate biocompatibility, faster degradation rate (Mg-based alloys), inflammatory response, infections, inertness (SS, Ti, and Co-Cr alloys), lower corrosion resistance, elastic modulus mismatch, excessive wear, and shielding stress. Therefore, to address this problem, it is necessary to develop a method to improve the biofunctionalization of metallic implant surfaces by changing the materials’ surface and morphology without altering the mechanical properties of metallic implants. Among various methods, surface modification on metallic surfaces by applying coatings is an effective way to improve implant material performance. In this review, we discuss the recent developments in ceramics, polymers, and metallic materials used for implant applications. Their biocompatibility is also discussed. The recent trends in coatings for biomedical implants, applications, and their future directions were also discussed in detail.

… lactic) acid (PLA) coating to control corrosion rates of biodegradable pure Fe and Zn in a physiological environment. PLA accelerated the degradation of both Fe and Zn, attributed to the …

… Zn is an excellent choice for temporary orthopaedic implants … The current work focuses on modifying the Zn-1Mg surface to … coating with porous morphology was initially created on Zn-…

… samples increased with increasing copper content of the coatings. In summary, γ-PGA-g-DA/Cu coatings provide a feasible strategy to design Zn alloy implant materials with improved …

… the corrosion rate of active metals (eg, Mg, Zn) used for the fabrication of temporary implants. … The organic polymeric component allows control of not only the implant dissolution rate, but …

… for long-term implant coatings where mechanical integrity … in bone grafts and temporary implant coatings. • Porosity and … enhancement of HAp coating and characterization for Mg-Zn-Ca-…

… Here, SiO 2 containing PVB coatings applied on zinc is shown to inhibit corrosion-driven organic coating disbondment and even to self-heal the already delaminated interface. The …

Biodegradable zinc (Zn) has attracted increasing interest as a material for temporary implants, primarily due to its moderate degradation kinetics. In recent years, additive manufacturing of Zn alloys using the laser powder bed fusion method (L-PBF) has shown promising results. Compared to as-cast Zn alloys, it offers preferable customized solutions for patient-specific temporary biomedical implants. Due to the novelty of these printed degradable biomaterials and due to reported cytotoxic effects of Zn alloys, this study investigates additively manufactured ZnAgCu, ZnAgCuMn, and ZnAgCuTi alloys, both in as-printed and post-processed conditions, with a focus on L929 and SAOS-2 biocompatibility. In this work, we demonstrate that the increased porosity and therefore larger surface areas compared to polished Zn-alloy samples affect their biocompatibility. Minimal to no cell proliferation was observed on and near the Zn-alloy test plates after 24 h. Undiluted extracts from as-cast Zn and L-PBF-manufactured plates were initially cytotoxic to SAOS-2 cells. However, as passivation proceeded, cytocompatibility was significantly increased from day 3 onward. Zn2+ ion release peaked at 24 h and declined significantly from day 2 to day 10. Compared to the other Zn alloys, ZnAgCuMn exhibited the lowest cytocompatibility. Most intriguingly, 3-month surfaces exhibited reduced cytocompatibility to osteoblasts compared to freshly polished samples. The observed in vitro cytotoxicity motivates further investigation of as-printed and post-processed L-PBF-manufactured Zn alloys, aiming to develop novel surface modification strategies to mitigate the initial ion burst responsible for reduced cytocompatibility and to adjust and tailor the overall degradation kinetics to physiologically tolerable levels tailored to the intended clinical application.

The improvement of biodegradable metals is currently an active and promising research area for their capabilities in implant manufacturing. However, controlling their degradation rate once their surface is in contact with the physiological media is a challenge. Surface treatments are in the way of addressing the improvement of this control. Zinc is a biocompatible metal present in the human body as well as a metal widely used in coatings to prevent corrosion, due to its well-known metal protective action. These two outstanding characteristics make zinc coating worthy of consideration to improve the degradation behaviour of implants. Electrodeposition is one of the most practical and common technologies to create protective zinc coatings on metals. This article aims to review the effect of the different parameters involved in the electrochemical process on the topography and corrosion characteristics of the zinc coating. However, certainly, it also provides an actual and comprehensive description of the state-of-the-art of the use of electrodeposited zinc for biomedical applications, focusing on their capacity to protect against bacterial colonization and to allow cell adhesion and proliferation.

Recent studies have indicated a great demand to optimize the biocompatibility properties of pure Zn as an implant material. For this purpose, CaZn2(PO4)2·2H2O (CaZnP) was prepared using hydrothermal treatment (HT) combined with micro-arc oxidation (MAO) on pure Zn substrate to generate biodegradable implants. The polarization test and electrochemical impedance spectroscopy indicated that the MAO1−HT coating could modulate the corrosion behavior of MAO1 by filling the crevice between the coating and the substrate. Immersion test evaluation revealed that the osteogenic properties of MAO1−HT coating were better than that of pure Zn substrate, as evidenced by the molar ratio of Ca and P, which increased after soaking in simulated body fluid (SBF) for up to 10 days. In addition, L-929 cells cultured in the 100%, 50%, and 25% extracts of MAO1−HT coated samples exhibited excellent cytocompatibility. Meanwhile, cell adhesion was promoted on the surface with high roughness generated during MAO and HT processes. In summary, the calcified coatings improved biocompatibility and adjusted the degradation rates of pure Zn, broadening the application of Zn alloys.

Zinc (Zn)-based biodegradable alloys have been at the forefront of absorbable biomaterial research in recent years due to their high biocompatibility and corrosion rates. The arc melting process was used to produce the Zn–1Cu–1Ag biodegradable alloy. The influence of different plastic deformation rates on the microstructure of the material was examined after the cold rolling at deformation rates of 47% and 61%. The undeformed and deformed alloys have been hydroxyapatite-coated using the electrophoretic deposition process to improve its surface, corrosion, and bioactivity properties. Optical, XRD, SEM, and EDS examinations were used to analyze the samples’ uncoated, coated, and rolled-unrolled forms. The nucleation of the (Ag, Cu)Zn4 secondary phase was formed during the rolling process. Hardness and compression tests were used to determine the mechanical properties of cast and rolled alloys, and in vitro corrosion tests were carried out in simulated body fluid. Antimicrobial and cell viability tests are executed to demonstrate the biocompatibility of the deformed and HA-coated Zn–1Cu–1Ag alloy. The mechanical properties were improved after the rolling process, with the highest results found in 47% of the rolled samples exhibiting a compressive strength of 412.65 ± 0.5 MPa and 61% of the rolled samples exhibiting a hardness value of 88.1 ± 0.5 HV. The samples that were rolled (61%) and coated with hydroxyapatite (HA) exhibited the highest level of corrosion resistance. The antimicrobial tests revealed that the rolled and HA coated Zn1Cu1Ag groups exhibited greater inhibition rates (47 and 61%) compared to the other groups when tested against E. coli. The HA-coated groups exhibited good cell viability ratios, with the maximum viability seen in the rolled and HA-coated group at 47%.

Zinc-based biodegradable metals (BMs) have been developed for biomedical implant materials. However, the cytotoxicity of Zn and its alloys has caused controversy. This work aims to investigate whether Zn and its alloys possess cytotoxic effects and the corresponding influence factors. According to the guidelines of the PRISMA statement, an electronic combined hand search was conducted to retrieve articles published in PubMed, Web of Science, and Scopus (2013.1–2023.2) following the PICOS strategy. Eighty-six eligible articles were included. The quality of the included toxicity studies was assessed utilizing the ToxRTool. Among the included articles, extract tests were performed in 83 studies, and direct contact tests were conducted in 18 studies. According to the results of this review, the cytotoxicity of Zn-based BMs is mainly determined by three factors, namely, Zn-based materials, tested cells, and test system. Notably, Zn and its alloys did not exhibit cytotoxic effects under certain test conditions, but significant heterogeneity existed in the implementation of the cytotoxicity evaluation. Furthermore, there is currently a relatively lower quality of current cytotoxicity evaluation in Zn-based BMs owing to the adoption of nonuniform standards. Establishing a standardized in vitro toxicity assessment system for Zn-based BMs is required for future investigations.

Biodegradable zinc (Zn) alloys stand out as promising contenders for biomedical applications due to their favorable mechanical properties and appropriate degradation rates, offering the potential to mitigate the risks and expenses associated with secondary surgeries. While current research predominantly centers on the in vitro examination of Zn alloys, notable disparities often emerge between in vivo and in vitro findings. Consequently, conducting in vivo investigations on Zn alloys holds paramount significance in advancing their clinical application. Different element compositions and processing methods decide the mechanical properties and biological performance of Zn alloys, thus affecting their suitability for specific medical applications. This paper presents a comprehensive overview of recent strides in the development of biodegradable Zn alloys, with a focus on key aspects such as mechanical properties, toxicity, animal experiments, biological properties, and molecular mechanisms. By summarizing these advancements, the paper aims to broaden the scope of research directions and enhance the understanding of the clinical applications of biodegradable Zn alloys.

Traditional inert materials used in internal fixation have caused many complications and generally require removal with secondary surgeries. Biodegradable materials, such as magnesium (Mg)-, iron (Fe)- and zinc (Zn)-based alloys, open up a new pathway to address those issues. During the last decades, Mg-based alloys have attracted much attention by researchers. However, the issues with an over-fast degradation rate and release of hydrogen still need to be overcome. Zn alloys have comparable mechanical properties with traditional metal materials, e.g., titanium (Ti), and have a moderate degradation rate, potentially serving as a good candidate for internal fixation materials, especially at load-bearing sites of the skeleton. Emerging Zn-based alloys and composites have been developed in recent years and in vitro and in vivo studies have been performed to explore their biodegradability, mechanical property, and biocompatibility in order to move towards the ultimate goal of clinical application in fracture fixation. This article seeks to offer a review of related research progress on Zn-based biodegradable materials, which may provide a useful reference for future studies on Zn-based biodegradable materials targeting applications in orthopedic internal fixation.

… as coating processes, heat treatments, material surface struc… Zn promotes wound healing and vascularization, making it a … which Zn was poured, resulting in Zn bone scaffolds with two …

Zinc (Zn) and its alloys have emerged as promising candidates for biomedical materials, owing to their controlled degradation kinetics, intrinsic biocompatibility, and the release Zn2+ ions which are known to promote bone regeneration and tissue healing. Despite their potential, the widespread clinical adoption of Zn alloys has been hindered by insufficient mechanical properties, design limitations of traditional manufacturing, and limited clinical validation. Recent advances in additive manufacturing (AM), particularly laser powder bed fusion (LPBF), are revolutionizing the production of Zn alloy implants. LPBF enables unprecedented design freedom and accuracy, allowing the fabrication of patient-specific, geometrically-intricate and porous structures with unique functionality that are previously unattainable. This review aims to provide a comprehensive overview of the latest progress in LPBF processing of Zn alloys, focusing on structure design, fabrication, microstructural characteristics, and mechanical and biological properties—critical factors for real applications of functional implants, particularly in cardiovascular and orthopedic fields. Additionally, this review examines the role of post-processing treatments, such as heat treatments and surface modifications, in adjusting degradation rate, controlling Zn2+ ion release, and improving cell viability, proliferation and differentiation, all of which are vital for achieving predictable and reliable in vivo outcomes. Further, the review seeks to synthesize these advances and their interplays to provide a strategic insight for translating patient-specific, biodegradable Zn implants into clinical practice.

Zinc (Zn) has recently been identified as an auspicious biodegradable metal for medical implants and devices due to its tunable mechanical properties and good biocompatibility. However, the slow corrosion rate of Zn in a physiological environment does not meet the requirements for biodegradable implants, hindering its clinical translation. The present study aimed to accelerate the corrosion rate of pure Zn by utilizing acid etching to roughen the surface and increase the substrate surface area. The effects of acid etching on surface morphology, surface roughness, tensile properties, hardness, electrochemical corrosion and degradation behavior, cytocompatibility, direct cell attachment, and biofilm formation were investigated. Interestingly, acid-treated Zn showed an exceptionally high rate of corrosion (∼226-125 μm/year) compared to untreated Zn (∼62 μm/year), attributed to the increased surface roughness (Ra ∼ 1.12 μm) of acid-etched samples. Immersion tests in Hank's solution revealed that acid etching accelerated the degradation rate of Zn samples. In vitro, MC3T3-E1 cell lines in 50 and 25% conditioned media extracts of treated samples showed good cytocompatibility. Reduced bacterial adhesion, biofilm formation, and dispersion were observed for Staphylococci aureus biofilms cultured on acid-etched pure Zn substrates. These results suggest that the surface modification of biodegradable pure Zn metals by acid etching markedly increases the translation potential of zinc for various biomedical applications.

… the excessive Zn ions released during degradation. In order to solve these problems, dopamine modified … This provided a new strategy for the surface modification of biodegradable Zn. …

… Na 2 CO 3 electrolyte on pure Zn surface for elucidating the influence of PEO treatment on … degradation behavior of Zn and Zn-based materials. Degradation effects, including surface …

Zn-0.8 wt.% Li-0.1 wt.% Mn wire with the diameter of 0.3 mm was fabricated and further processed into gastrointestinal staple, and its in vitro and in vivo biodegradation and biocompatibility was studied systematically. The experimental Zn-Li-Mn alloy staple could deform from the original U-shape to B-shape without fracture, indicating its good mechanical property. Due to the residual stress concentration caused by anastomosis deformation, the feet and leg arc part of the staple were more prone to degradation. The Zn-Li-Mn alloy staple sustained integrity after immersion in Hanks' solution and simulated gastric fluid (SGF) for 28 days, and the degradation rate in SGF was about 4 times of that in Hanks' solution. Furthermore, Zn-Li-Mn alloy staples were utilized for gastrointestinal anastomosis in pig models, with clinically-used titanium alloy staples as a comparison. No anastomotic leakage and severe inflammation were observed after operation. The Zn-Li-Mn alloy staple maintained mechanical integrity within 8 weeks' implantation. The gastrointestinal tissue healed after 12 weeks, and no obvious side effects were detected during the whole implantation period, demonstrating the good biocompatibility of Zn-Li-Mn alloy staple. Thus, Zn-Li-Mn alloy staple fabricated in this work displayed the promising potential in the gastrointestinal anastomosis.

Zinc–magnesium (Zn–Mg) alloys, fabricated by laser powder bed fusion (LPBF) additive manufacturing techniques, have emerged as promising candidates for biomedical implants due to their biodegradation capability, superior mechanical strength, and excellent biocompatibility. However, LPBF-fabricated Zn–Mg alloys still face challenges related to extremely low ductility and limited exploration of degradation characteristics. In this study, the impact of Mg incorporation on the printability, degradation properties, microstructure, and mechanical properties of LPBF-fabricated Zn–Mg alloys was primarily investigated. Furthermore, we proposed a viable annealing post-processing route for the first time to tailor the microstructural characteristics of the fabricated Zn–Mg alloy and enhanced its limited ductility. The results demonstrated that by applying a laser power of 80 W and a scanning speed of 600 mm/s, the relative density of LPBF-fabricated Zn–Mg alloy reached 98.62%. Increasing the Mg amount from 1 to 5 wt% refined the grain size while promoting an increase in Mg2Zn11 and MgZn2 phases. Among these compositions, the Zn–1Mg alloy exhibited the greatest degradation rate at 0.126 mm/year. The annealing treatment facilitated the microstructure evolution of the Zn–1Mg alloy, resulting in equiaxed grains, increased average grain size, high-angle grain boundaries, and enrichment of Mg at grain boundaries. After annealing at 300°C for 0.5 h, the tensile strength of Zn– 1Mg alloy decreased from 254.92 to 170.93 MPa, while the elongation significantly increased by a factor of 14.3 from 0.55% to 8.43%. These findings provide valuable insights into an effective post-processing approach for tailoring the microstructure and resultant mechanical properties of LPBF-fabricated Zn and its alloys.

Biomaterial implantation into the human body plays a key role in the medical field and biological applications. Increasing the life expectancy of biomaterial implants, reducing the rejection reaction inside the human body and reducing the risk of infection are the problems in this field that need to be solved urgently. The surface modification of biomaterials can change the original physical, chemical and biological properties and improve the function of materials. This review focuses on the application of surface modification techniques in various fields of biomaterials reported in the past few years. The surface modification techniques include film and coating synthesis, covalent grafting, self-assembled monolayers (SAMs), plasma surface modification and other strategies. First, a brief introduction to these surface modification techniques for biomaterials is given. Subsequently, the review focuses on how these techniques change the properties of biomaterials, and evaluates the effects of modification on the cytocompatibility, antibacterial, antifouling and surface hydrophobic properties of biomaterials. In addition, the implications for the design of biomaterials with different functions are discussed. Finally, based on this review, it is expected that the biomaterials have development prospects in the medical field.