Antibacterial Coatings Research Articles

Enhancing implant performance: 20% reduction in Pseudomonas aeruginosa bacterial initial formation with Cu0.75Ti0.25O2 coating

Bacteria are commonly found in various environmental sources, such as soil and water. Among the different bacterial species, Pseudomonas aeruginosa is particularly known for causing infections in humans and can easily colonize surfaces. To address this issue, one approach is to modify the surface with antibacterial coatings. Thus, here, we investigate the effectiveness of Cu–Ti oxide coatings by fabricating Cu1−xTixO2 (0.25 < x < 0.75) thin films on glass substrates using the pulsed laser deposition technique. Microstructural analysis revealed that the films were amorphous and exhibited a smooth surface. In addition, the contact angle measurements demonstrated high hydrophilicity, as indicated by values below 90°. Subsequently, we examined the biofilm formation of Pseudomonas aeruginosa bacteria on both Cu1−xTixO2 coated and uncoated glass surfaces. The results revealed a 20% reduction in bacterial growth on Cu0.75Ti0.25O2-coated samples, as determined by calculating the biomass of the biofilm. These findings were further discussed in relation to the copper content present on the surface of the coating. Ultimately, the results contribute to our understanding of bacterial development on various surfaces. Consequently, this research may have practical implications for enhancing the antibacterial properties, preventing bacterial infections associated with different materials and surfaces, and improving implant performance.

Enhancing Antibacterial Performance: Structure, Phase Composition, and Microroughness of Selective Plated Copper Coatings on Medical-Grade Stainless Steel 1.4021 and Nickel Alloy Ni200

This study presents a preliminary characterization of selective plated antibacterial copper coatings on medical-grade stainless steel 1.4021 and nickel alloy Ni200 substrates using two different copper electrolyte solutions with acidic and alkaline pH. The characterizations included analysis of the microstructure, phase composition, surface roughness, and antibacterial activity against Gram-positive Staphylococcus aureus ATCC 29213 and Gram-negative Escherichia coli ATCC 25922 bacteria. The results revealed uniform and continuous layers of single-phase solid-solution copper coatings without any cracks or defects. The coatings, produced using acidic or alkaline solutions, exhibited approximately 20% or 40% lower surface roughness compared to the substrate roughness. This suggests that the plating process led to a smoother surface finish. Importantly, all of the selective plated copper coatings exhibited antibacterial properties. Inhibition zones were identified, indicating the ability of the coatings to inhibit the growth of both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The use of the alkaline copper solution resulted in slightly larger inhibition zones compared to the acidic solution, indicating enhanced antibacterial activity. These findings suggest that the selective plated copper coatings on medical-grade stainless steel 1.4021 and nickel alloy Ni200 substrates have the potential to be effective antibacterial surfaces.

Comparative Analysis of Performance of Water-Based Coatings Prepared by Two Kinds of Anti-Bacterial Microcapsules and Nano-Silver Solution on the Surface of Andoung Wood

A nano-silver solution, urea-formaldehyde resin-coated nano-silver solution microcapsules (AgNPS@UF), and melamine-formaldehyde resin-coated chitosan-modified nano-silver solution microcapsules (CS-AgNPS@MF) were added into the coatings at different contents for comparative tests to explore an anti-bacterial agent with the best anti-bacterial properties in the water-based coatings on Andoung wood (Monopetalanthus spp.). As the content of anti-bacterial agents increased, AgNPS@UF had the best anti-bacterial property towards Staphylococcus aureus and Escherichia coli, with anti-bacterial rates of 79.0% and 82.1%, respectively. The optical and mechanical properties of the coating quickly worsened as the content of anti-bacterial agents increased. The anti-bacterial coatings with AgNPS@UF have the minimum chromatic aberration change of 6.5. The anti-bacterial coating with 5% content of AgNPS@UF decreased the aging rate. This coating had good optical properties, and its liquid-resistant level is 2. When the 5% content of AgNPS@UF was added, after high-temperature accelerated aging and ultraviolet (UV) aging, the anti-bacterial rates of the coating with AgNPS@UF decreased toward Escherichia coli from 82.1% to 62.2% and decreased toward Staphylococcus aureus from 79.3% to 61.1%, respectively. This shows that the coating had a long-lasting anti-bacterial property. The anti-bacterial property of the coating after high-temperature accelerated aging was superior to that after the UV aging. The incorporation of AgNPS@UF in water-based coatings protects people from the risks of Escherichia coli and Staphylococcus aureus more effectively with long-lasting property. The research results provide a reference for the preparation of anti-bacterial water-based coatings on the surface of the Andoung wood.

Se-doped Nb2O5–Al2O3 composite-ceramic nanoarrays via the anodizing of Al/Nb bilayer in selenic acid

Novel arrays of Nb2O5-based ceramic nanostructures of various sizes (9–210 nm) and morphologies (dots, goblets, rods) aligned on substrates are fabricated via the anodizing of a thin Nb film through the initially formed porous anodic alumina (PAA) film in 1.5 M selenic acid (H2SeO4) – a new aqueous electrolyte generating extraordinarily thinner PAA pores than any other solutions. Accordingly, the nanostructures formed in the selenic acid are 1.3-fold thinner and better self-ordered than their counterparts formed from the same Al/Nb precursor bilayer in a reference oxalic-acid electrolyte. The nanostructures have a dual (core/shell) composition: the inner material (the core) is stoichiometric Nb2O5, whereas the outer layer (the shell) is a few nm-thick substoichiometric NbOx mixed with Al2O3. The composite-ceramic nanoarrays grow doped with selenium species such as selenate (SeO42−) and selenide (Se2−) anions originating from the electrolyte and migrating inward under the high electric field. The incorporated Se species do not contribute to photoluminescence emission nor hinder the Raman signal from the nanoarrays, which makes them highly promising as Nb2O5-based SERS biosensing substrates. The planar PAA-inbuilt Se-doped Nb2O5–Al2O3 nanostructured ceramic film performs like a high-k low-loss low-leakage-current dielectric promising for on-chip integration. More potential applications of the Se-doped ceramic nanoarrays developed here include biomedical antibacterial coatings, advanced superhydrophobic surfaces, gas-sensing, and catalytic layers.

Antibacterial Analysis on Everolimus Grafted Biomaterial Surfaces using Polydopamine Intermediate Layer for Potential Use on Medical Devices

Biomaterial-Centered Infection (BCI) is a significant issue in the implantation of medical devices, primarily caused by the formation of bacterial biofilms on the device surface. One potential solution to address this problem is the use of antibacterial coatings. This study examines the effectiveness of everolimus as an antibacterial coating agent with polydopamine (PDA) as an intermediate layer. The commonly used biomaterial for medical scaffolds, poly(lactic acid) (PLA), was coated with everolimus after being submerged in PDA for 24 hours. The coated PLA was then subjected to antibacterial analysis, including culturing Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria in Luria-Bertani broth, bacterial count tests, and disc inhibition tests. The results showed that everolimus has antibacterial properties, but its efficacy varies with different types of bacteria adhering to the biomaterial surfaces. Specifically, the everolimus coating was found to be more effective in killing Gram-positive S. aureus. The absence of inhibition zones and the lack of further growth of both Gram-positive S. aureus and Gram-negative E. coli on the samples demonstrated the controlled release of everolimus, indicating the potential of the PDA layer in holding the everolimus release to the surrounding. Therefore, the study concludes that the formation of everolimus coating on biomaterial surfaces aided by the PDA layer, have significant potential in retarding bacterial colonies on medical devices.

Intrinsic antibacterial thermosets resin from eugenol and soybean oil: Synthesis and properties

The use of solvent-free approach to manufacture antibacterial epoxy coatings with high renewable carbon content is of important for environmental sustainability and the diversity of antibacterial materials. Herein, an epoxy monomer with inherent antibacterial properties, eugenol-modified epoxidized soybean oil (EUESO) with totally natural carbon was synthesized from renewable epoxidized soybean oil (ESO) and eugenol via one-step solvent-free method. Then, EUESO was cured with DGEBA and 4, 4′-diaminodicyclohexylmethane (HDDM) to construct mechanically robust and anti-release antibacterial epoxy coatings. The influence of the weight ratio of EUESO on epoxy coating and comprehensive performance was systematically studied. According to DSC, TGA and bending test on the thermal and mechanical properties of the cured resins, all cured resins demonstrated high thermodynamic properties and high Tg. Meanwhile, in the dynamic shake test, all cured resins demonstrated a certain degree of killing effect on Escherichia coli (E. coli), with a maximum killing rate of 93.8% as the concentration of EUESO increased.

Antibacterial CATH‐2 Peptide Coating to Prevent Bone Implant‐Related Infection

AbstractThe development of antibacterial coatings is a promising approach to preventing biofilm formation and reducing the overuse of systemic antibiotics. However, widespread antibiotic use has resulted in antibiotic‐resistant bacteria, limiting the efficacy of antibiotic‐based coatings. Herein, an antibacterial coating is developed by layer‐by‐layer (LbL) assembly of two polymers namely PDLG (poly (D,L‐lactide‐co‐glycolide)) and gelatin methacryloyl (GelMA) while chicken cathelicidin‐2 (CATH‐2), a cationic and amphipathic peptide, is loaded between these polymer layers. The electrospray method is used to apply the coatings to achieve efficient peptide loading and durability. The CATH‐2 bactericidal concentration ranges are first identified, followed by a study of their cytotoxicity to human mesenchymal stem cells (hMSCs) and macrophage cell lines. Later, different LbL electrospray coating assemblies loaded with the optimal peptide concentration are sought. Various coating strategies are investigated to identify an LbL coating that exhibits prolonged and biocompatible CATH‐2 release. The resulting CATH‐2‐coated titanium surfaces exhibit strong antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria for 4 days and are biocompatible with hMSCs and macrophage cells. This coating can be considered as a versatile delivery system platform for the delivery of CATH‐2 peptides while avoiding cytotoxicity, particularly for the prevention of infections associated with implants.

Electrophoretic deposition of tetracycline loaded bioactive glasses/chitosan as antibacterial and bioactive composite coatings on magnesium alloys

Electrophoretic deposition (EPD) is a coating technique which is widely applied to improve the biocompatibility and anticorrosive performance of medical metal alloys. In this paper EPD was employed to deposit bioactive glasses(BGs)-chitosan(CS) coating loaded with model drug tetracycline(TCH) on AZ31B magnesium alloy to enhance its anti-inflammation, anti-bacteria, anticorrosion and osteogenic induction properties. The electrochemical test showed that the corrosion current density of CS-BGs-1.0 TCH coating was 2 orders of magnitude lower than that of bare AZ31B. In vitro biological activity revealed that after 3 d of immersion in simulated body fluid, the surface of the coating was covered with a layer of hydroxyapatite. In vitro drug release test showed that the drug in CS-BGs-1.0 TCH could be effectively released for 504 h, providing resistance to the formation of bacterial film in a long time. In vitro antibacterial tests indicated that the coating significantly improved the antibacterial activity of magnesium alloy against E.coli. As a result, the prepared coating had better corrosion resistance, antibacterial and biological activity. This coating has good potential in the application of medical devices and bone implant materials.

The Intraoperative Use of Defensive Antibacterial Coating (DAC®) in the Form of a Gel to Prevent Peri-Implant Infections in Orthopaedic Surgery: A Clinical Narrative Review.

Periprosthetic joint infections (PJIs) in arthroplasty and osteosynthesis-associated infections (OAIs) in reconstructive surgery still represent a challenging complication in orthopaedics and traumatology causing a burden worsening the patient's quality of life, for caregiver and treating physicians, and for healthcare systems. PJIs and OAIs are the result of bacterial adhesion over an implant surface with subsequent biofilm formation. Therefore, the clinical pathological outcome is a difficult-to-eradicate persistent infection. Strategies to treat PJIs and OAIs involve debridement, the replacement of internal fixators or articular prostheses, and intravenous antibiotics. However, long treatments and surgical revision cause discomfort for patients; hence, the prevention of PJIs and OAIs represents a higher priority than treatment. Local antibiotic treatments through coating-release systems are becoming a smart approach to prevent this complication. Hydrophilic coatings, loaded with antibiotics, simultaneously provide a barrier effect against bacterial adhesion and allow for the local delivery of an antibiotic. The intraoperative use of a hyaluronan (HY)-derivative coating in the form of a gel, loaded with antibiotics to prevent PJI, has recently raised interest in orthopaedics. Current evidence supports the use of this coating in the prophylaxis of PJI and IRIs in terms of clinical outcomes and infection reduction. Thus, the purpose of this narrative review is to assess the use of a commercially available HY derivative in the form of a gel, highlighting the characteristics of this biomaterial, which makes it attractive for the management of PJIs and IRIs in orthopaedics and traumatology.

A Bioinspired Atomically Thin Nanodot Supported Single-Atom Nanozyme for Antibacterial Textile Coating.

Surface antibacterial coatings with outstanding antibacterial efficiency have attracted increasing attention in medical protective clothing and cotton surgical clothing. Although nanozymes, as a new generation of antibiotics, are used to combat bacteria, their catalytic performance remains far from satisfactory as alternatives to natural enzymes. Single-atom nanodots provide a solution to the low catalytic activity bottleneck of nanozymes. Here, atomically thin C3 N4 nanodots supported single Cu atom nanozymes (Cu-CNNDs) are developed by a self-tailoring approach, which exhibits catalytic efficiency of 8.09 × 105 M-1 s-1 , similar to that of natural enzyme. Experimental and theoretical calculations show that excellent peroxidase-like activity stems from the size effect of carrier optimizing the coordination structure, leading to full exposure of Cu-N3 active site, which improves the ability of H2 O2 to generate hydroxyl radicals (•OH). Notably, Cu-CNNDs exhibit over 99% superior antibacterial efficacy and are successfully grafted onto cotton fabrics. Thus, Cu-CNNDs blaze an avenue for exquisite biomimetic nanozyme design and have great potential applications in antibacterial textiles.

Bacterial Biofilm Formation on Biomaterials and Approaches to Its Treatment and Prevention.

Bacterial biofilms can cause widespread infection. In addition to causing urinary tract infections and pulmonary infections in patients with cystic fibrosis, biofilms can help microorganisms adhere to the surfaces of various medical devices, causing biofilm-associated infections on the surfaces of biomaterials such as venous ducts, joint prostheses, mechanical heart valves, and catheters. Biofilms provide a protective barrier for bacteria and provide resistance to antimicrobial agents, which increases the morbidity and mortality of patients. This review summarizes biofilm formation processes and resistance mechanisms, as well as the main features of clinically persistent infections caused by biofilms. Considering the various infections caused by clinical medical devices, we introduce two main methods to prevent and treat biomaterial-related biofilm infection: antibacterial coatings and the surface modification of biomaterials. Antibacterial coatings depend on the covalent immobilization of antimicrobial agents on the coating surface and drug release to prevent and combat infection, while the surface modification of biomaterials affects the adhesion behavior of cells on the surfaces of implants and the subsequent biofilm formation process by altering the physical and chemical properties of the implant material surface. The advantages of each strategy in terms of their antibacterial effect, biocompatibility, limitations, and application prospects are analyzed, providing ideas and research directions for the development of novel biofilm infection strategies related to therapeutic materials.

Structural design of a hyperbranched chitosan-based bioplastic with excellent strength, antibacterial, and UV shielding performance

Renewable biomaterials have received increasing attention as ideal alternatives to non-biodegradable plastics, but the poor water resistance, antibacterial property, and bonding strength usually limit their development. Inspired by the mussel chemistry, a sustainable and facile strategy is reported for preparing a high-performance chitosan (CS)-based film by incorporating a water-soluble hyperbranched polyamide (HB) and inorganic–organic system. Nanofibrillated cellulose (NFC) serves as a biological template for the preparation of uniformly dispersed zinc oxide quantum dots (ZnO QDs). As a dynamic glue linkage, protocatechualdehyde (PA) containing catechol groups provides additional bridging between the ZnO QDs and the organic CS biopolymer, thus guiding the ZnO QDs to disperse more evenly in the CS matrix and promoting the multiple cross-linking interactions in the hybrid film. The toughness and strength of the composites are simultaneously increased by 276.7% and 150.9%, respectively. Owing to the optimization of hyperbranched structure, catechol chemistry, and inorganic–organic system, the resultant film also exhibits substantially improved water resistance, thermal stability, and UV shielding capability. Additionally, the functional ZnO QDs, catechol PA, and cationic CS synergistically endow the film with superior antibacterial properties. This novel and biomimetic strategy opens up new ideas for the design of multifunctional bioplastics, while driving the development of CS biomaterials in the areas of antibacterial adhesives, high-strength hydrogels, and UV resistant coatings.

Zein/chitosan composite nanospheres for controlled release of fragrances

The controlled release of fragrances is critical for cosmetics industry, but most traditional fragrance carriers have some limitations. In this study, ethanol soluble protein zein was selected as the matrix to encapsulate ethanol soluble cinnamaldehyde (CA) with the addition of another natural polymer chitosan (CS), forming composite nanospheres. The zein/CS composite nanospheres showed three different structures depending on the zein/CS mass ratio. The hydrophobic interaction between CA and zein, and the formation of Schiff base between CA and CS significantly reduced its volatilization rate to the air. In addition, it was found that the loading capacity, encapsulation efficiency, controlled release property, and antibacterial activity of the CA-loaded zein/CS composite nanospheres were closely related to their structure. The nanospheres with core (zein)/shell (CS) or homogenous structure displayed long CA release time (more than 1 day) and sustained antibacterial activity against Staphylococcus aureus. Therefore, the CA-loaded zein/CS composite nanospheres are promising carriers for developing antibacterial perfumes and coatings.

A Facile Strategy to Construct Anti-Swelling, Antibacterial, and Antifogging Coatings for Protection of Medical Goggles.

During the COVID-19 (Corona Virus Disease 2019) pandemic, traditional medical goggles are not only easy to attach bacteria and viruses in long-term exposure, but easy to fogged up, which increases the risk of infection and affects productivity. Bacterial adhesion and fog can be significantly inhibited through the hydrogel coatings, owing to super hydrophilic properties. On the one hand, hydrogel coatings are easy to absorb water and swell in wet environment, resulting in reduced mechanical properties, even peeling off. On the other hand, the hydrogel coatings don't have intrinsic antibacterial properties, which still poses a potential risk of bacterial transmission. Herein, an anti-swelling and antibacterial hydrogel coating is synthesized by 2-hydroxyethyl methacrylate (HEMA), acrylamide (AM), dimethylaminoethyl acrylate bromoethane (IL-Br), and poly(sodium-p-styrenesulfonate) (PSS). Due to the self-driven entropy reduction effect of polycation and polyanion, an ion cross-linking network is formed, which endows the hydrogel coating with excellent antiswelling performance. Moreover, because of the synergistic effect of highly hydrated surfaces and the active bactericidal effect from quaternary ammonium cations, the hydrogel coating exhibits outstanding antifouling performances. This work develops a facile strategy to fabricate anti-swelling, antifouling, and antifogging hydrogel coatings for the protection of medical goggles, and also for biomedical and marine antifouling fields.

Do cationic polymer coatings retain their biocidal activity after washing with water?

Aqueous solutions of poly(diallyldimethylammonium chloride) and its electrostatic complexes with sodium polyacrylate were deposited onto glass surfaces. Upon successive washing cycles, they formed thin stable coatings that exhibited antimicrobial activity towards gram-positive and gram-negative bacteria. The obtained results are valuable for the development of antibacterial coatings.

Chitosan-Based Antibacterial Films for Biomedical and Food Applications.

Antibacterial chitosan films, versatile and eco-friendly materials, have garnered significant attention in both the food industry and medicine due to their unique properties, including biodegradability, biocompatibility, and antimicrobial activity. This review delves into the various types of chitosan films and their distinct applications. The categories of films discussed span from pure chitosan films to those enhanced with additives such as metal nanoparticles, metal oxide nanoparticles, graphene, fullerene and its derivatives, and plant extracts. Each type of film is examined in terms of its synthesis methods and unique properties, establishing a clear understanding of its potential utility. In the food industry, these films have shown promise in extending shelf life and maintaining food quality. In the medical field, they have been utilized for wound dressings, drug delivery systems, and as antibacterial coatings for medical devices. The review further suggests that the incorporation of different additives can significantly enhance the antibacterial properties of chitosan films. While the potential of antibacterial chitosan films is vast, the review underscores the need for future research focused on optimizing synthesis methods, understanding structure-property relationships, and rigorous evaluation of safety, biocompatibility, and long-term stability in real-world applications.

Antimicrobial and Biodegradable 3D Printed Scaffolds for Orthopedic Infections.

In bone tissue engineering, the performance of scaffolds underpins the success of the healing of bone. Microbial infection is the most challenging issue for orthopedists. The application of scaffolds for healing bone defects is prone to microbial infection. To address this challenge, scaffolds with a desirable shape and significant mechanical, physical, and biological characteristics are crucial. 3D printing of antibacterial scaffolds with suitable mechanical strength and excellent biocompatibility is an appealing strategy to surmount issues of microbial infection. The spectacular progress in developing antimicrobial scaffolds, along with beneficial mechanical and biological properties, has sparked further research for possible clinical applications. Herein, the significance of antibacterial scaffolds designed by 3D, 4D, and 5D printing technologies for bone tissue engineering is critically investigated. Materials such as antibiotics, polymers, peptides, graphene, metals/ceramics/glass, and antibacterial coatings are used to impart the antimicrobial features for the 3D scaffolds. Polymeric or metallic biodegradable and antibacterial 3D-printed scaffolds in orthopedics disclose exceptional mechanical and degradation behavior, biocompatibility, osteogenesis, and long-term antibacterial efficiency. The commercialization aspect of antibacterial 3D-printed scaffolds and technical challenges are also discussed briefly. Finally, the discussion on the unmet demands and prevailing challenges for ideal scaffold materials for fighting against bone infections is included along with a highlight of emerging strategies in this field.

Atmospheric Pressure Plasma Polymerization of Carvone: A Promising Approach for Antimicrobial Coatings

Medical devices are often vulnerable to colonization by nosocomial pathogens (bacteria), leading to infections. Traditional sterilization methods may not always be effective, and as a result, alternative options are being explored to prevent microbial contamination. Recently, scientists are emphasizing using plant-derived essential oils that possess inherent antibacterial properties to produce antimicrobial coatings using plasma polymerization technology carried out at atmospheric pressure (AP). This approach shows promise compared to other coating strategies that need several processing steps, including a high-vacuum system, and are laborious, such as the immobilization of antimicrobial materials on precoated layers in the low-pressure plasma polymerization approach. The present study demonstrates the potential of AP plasma polymerization for producing thin films with excellent antibacterial properties and surface characteristics. The resulting coatings are stable, smooth, and have high wettability, making them ideal for repelling bacteria. The calculated zeta potential and deposition rate for the films are also favorable. These AP plasma-polymerized thin films created from carvone show a reduction rate of more than 90% for Escherichia coli and Staphylococcus aureus bacteria. Our computational docking studies also reveal strong binding interactions between the original carvone monomer and both bacteria. The study suggests that these AP plasma-produced coatings have great potential as antibacterial coatings for biomedical devices.

Metal- and Peroxide-Free Silicone Rubbers with Antibacterial Properties Obtained at Room Temperature

Metal- and peroxide-free silicone rubbers were obtained via a reaction between amino-containing poly(dimethylsiloxanes) (amino-terminated (APDMS-1) or a copolymer with pendant amino groups (APDMS-2)) and iodine-containing polysiloxanes (PIMSs) (Menshutkin reaction). Simple mixing of functional polymers at room temperature resulted in forming silicone materials. The formation of ammonium cross-links was confirmed using solid-state 1H and 13C NMR spectroscopy. The equimolar ratio of NH2 groups to the I-containing moiety (1:1) was the most optimal among other ratios (2:1 and 1:2) to carry out cross-linking and led to the highest cross-linking density according to the swelling measurements. PIMS/APDMS-1 (1:1) rubbers had the lowest average molecular weight of segments between cross-links Mc = 250 compared to PIMSs/APDMS-1 (1:2) and (2:1) with Mc = 1110 and 390, respectively. The obtained silicone rubbers showed antibacterial activity against Escherichia coli and Staphylococcus aureus and thereby could be applied in biomedicine and the food industry as antibacterial coatings and materials.

Study on Zn-doped antibacterial bioactive coatings on Ti6Al4V titanium alloy surfaces by micro-arc oxidation

To enhance the bioactivity and antibacterial activity of titanium alloys, coatings with different content of Zn element were successfully formed on Ti6Al4V substrates by micro-arc oxidation (MAO). The microstructure and composition of the coatings were characterized, and the bioactive and antibacterial activities were evaluated by the contact angle, cell viability and plate colony counting experiments, respectively. The results show that when Zn2+ concentration of the electrolytes rises, the breakdown voltage and the process voltage decrease, while the duration of the micro-arc oxidation stage increases. The products of MAO in the coatings are mainly rutile and anatase phases. As Zn2+ concentration in the electrolyte increases, the content of crystalline phases reduces, the thickness and the surface roughness of coatings increase, and the porosity shows an increase overall. MAO coatings bond tightly to the substrates, forming a thin, dense barrier layer and a thick, porous outer accumulation layer. The increase of Zn content results in an increase of Ca and P content in the coatings and a rise in Ca/P ratio. The concentrations of Ti, O, Ca and Zn elements on the cross-section show a transition distribution. Moreover, the hydrophilicity of all coatings is improved. Zn-doped coatings improve the cell viability of preosteoblast MC3T3-E1 cells and macrophage RAW264.7 cells, and higher cell viability is observed on the coatings with higher Zn concentration. Although the MAO coatings with low Zn content increase bacterial adhesion compared to the substrate, the coatings with high Zn content show adequate antibacterial activity.