Antibacterial Coatings Research Articles

The Optimization of the Synthesis of Antibacterial Coatings on Ti6Al4V Coupons Obtained by Electron Beam Melting

Prosthetic joint infection represents a problem that worsens the patient’s quality of life and produces an economic impact on health systems. We report the anodization of Ti6Al4V coupons obtained by electron beam melting to produce a nanostructured surface. Anodization at 10 V produced TiO2 nanopores with a diameter in the range of 15–20 nm. Thereafter, Ag nanoparticles (AgNPs) were deposited in three different ways to provide antibacterial functionality to the coatings: electrochemically, thermally, and chemically. The electrochemical method did not provide good coverage of AgNPs. At 0.1 V of synthesis potential, cubic, octahedral, and truncated octahedral Ag crystals were obtained. The thermal method provided a good distribution of AgNPs but it damaged the TiO2 nanostructure. The chemical method showed the best distribution of AgNPs over the anodized surface and preserved the anodized nanostructure. For this reason, the chemical method was selected to perform further studies. Ag+ release was monitored in simulated body fluid at 37 °C, reaching 1.86 mg Ag+/L after 42 days. The antibacterial coating showed excellent antibacterial activity and inhibited biofilm formation for Staphylococcus epidermidis RP62A and Staphylococcus aureus V329 strains (lethality > 99.9% for both bacteria and assays).

The Effects of Three Antibacterial Nanoparticle Coatings on the Surface Characteristics of Stainless Steel

The Effects of Three Antibacterial Nanoparticle Coatings on the Surface Characteristics of Stainless Steel

Cu enhances the photothermal effect of a TiN film for antibacterial applications

In recent years, diseases caused by the spread of hazardous microorganisms (e.g., bacteria) have become a growing global concern. Imparting antimicrobial properties to the surface of a material is critical for the prevention of bacterial disease transmission. In this study, titanium nitride/copper composite (TiN-CuX) films with excellent antibacterial properties were deposited on AISI 304 stainless steel (304ss) via magnetron sputtering. The TiN-CuX composite films exhibited excellent photothermal performance under near-infrared (NIR, 808 nm) irradiation: the temperature of a TiN-CuX composite film surface exposed to a bacterium-containing medium increased rapidly, resulting in the death of bacteria on the surface (∼100 %). The TiN–Cu600 film exhibited 70.8 % antibacterial activity owing to the release of Cu2+ in the absence of NIR irradiation. The TiN-CuX composite films prepared in this study demonstrated outstanding antibacterial capabilities owing to synergy between the photothermal effect and Cu2+ release. The TiN-CuX composite films prepared in this study are intended for use as photothermal antibacterial coatings and represent a new approach for the production of antibacterial coatings on material surfaces.

INTRAOPERATIVE USE OF DEFENSIVE ANTIBACTERIAL COATING (DAC) FOR COMPLEX SURGERIES IN COMPLEX HOSTS

Periprosthetic joint infections (PJIs) and osteosynthesis-associated infections (OSIs) present significant challenges in trauma and orthopaedic surgery, substantially impacting patient morbidity, mortality, and economic burden. This concern is heightened in patients with pre-existing comorbidities, such as diabetes mellitus, which are not always modifiable at presentation. A novel intraoperative strategy to prevent these infections is the use of Defensive Antibacterial Coating (DAC), a bio-absorbable antibiotic-containing hydrogel applied to implant surfaces at implantation, acting as a physical barrier to prevent infection.The purpose of this study is to assess the use of a commercially available hydrogel (DAC), highlighting its characteristics that make it suitable for managing PJIs and OSIs in orthopaedics and traumatology. Twenty-five patients who underwent complex orthopaedic procedures with intraoperative application of DAC between March 2022 and April 2023 at a single hospital site were included. Post-operative assessment encompassed clinical, laboratory, and radiographic examinations.In this study, 25 patients were included, with a mean age of 70 ± 14.77 years and an average ASA grade of 2.46 ± 0.78. The cohort presented an average Charleston Comorbidity score of 5.45 ± 2.24. The procedures included 8 periprosthetic fractures, 8 foot and ankle surgeries, 5 upper limb surgeries, and 4 elective hip and knee surgeries. Follow-up assessments at 6 weeks and 6 months revealed no evidence of PJI or OSI in any patients, nor were any treatments for PJI or OSI required during the interim period.DAC demonstrated efficacy in preventing infections in high-risk patients undergoing complex orthopaedic procedures. Our findings warrant further investigation into the use of DAC in complex hosts with randomized control trials.

SnS2 and Ho-doped SnS2 thin films: Synergistic, DFT, photocatalytic, and antibacterial studies

This study investigates Ho-doped tin disulfide (Ho-SnS2) thin films prepared via spray coating, focusing on varying Ho doping levels (0 at. %, 2 at. %, and 4 at. %). Structural analysis through XRD and SEM showcased enhanced crystallinity and morphology in Ho-SnS2 films. Raman and XPS studies provided insight into the film's composition and chemical states. The antibacterial properties of the films were investigated using a bacterial growth inhibition assay. The results showed significant antibacterial activity against Gram-positive and Gram-negative bacteria, highlighting the potential applications of Ho-SnS2 thin films in antibacterial coatings. Ho-SnS2 films exhibited superior photocatalytic activity and antibacterial properties compared to SnS2 films, attributed to efficient charge separation. DFT analysis proposed a mechanism for the antibacterial activity. These findings highlight the efficacy of the spray coating technique in producing Ho-SnS2 films and the potential of Ho-SnS2 films for diverse applications like photocatalysis and antibacterial coatings.

Durable antibacterial coatings on Kirschner wires via redox-assisted co-deposition

The Kirschner wire (K-wire) is a versatile and effective external fixator in orthopedic surgery. However, a recognized challenge associated with the use of K-wires is the potential for bacterial migration and subsequent infection as the wire passes through the skin and penetrates the bone. In this study, we developed a straightforward method for depositing antibacterial ions on K-wires by redox-assisted co-deposition. This method offers several advantages over conventional coating techniques, including uniformity, high coverage, strong adhesion, and scalability. As a result, K-wires treated with this method have a rapid and long-lasting antimicrobial effect. Both in vitro and in vivo experiments have demonstrated that these antimicrobial K-wires have an excellent bacterial elimination. The results of this study provide new opportunities for the application of robust and multifunctional antibacterial coating materials on implantable devices with great potential in the fields of orthopedics, transplantation and surgery.

Antibacterial sol-gel AgMnFe2O4 composite coatings added with degradable MgO

Antibacterial sol-gel AgMnFe2O4 composite coatings added with degradable MgO

Microstructural and antibacterial properties of copper oxide deposited on polypropylene fabric by magnetron sputtering

In this study, antibacterial coatings composed of copper and its oxides were deposited on polypropylene (PP) fabrics using magnetron sputtering. The coatings were deposited under varying oxygen partial pressures to facilitate the formation of cupric and cuprous oxides in different quantities. The formation of these oxides was confirmed by the surface morphology (Scanning Electron Microscopy [SEM]) and X-Ray Diffraction (XRD) analysis. Additionally, the antibacterial properties of the coated fabrics were evaluated. The results show that both copper and copper oxides achieved a 4-log reduction in gram-positive bacteria. Inductively Coupled Plasma Mass Spectroscopy (ICPMS) results indicated that the release of copper atoms into water from the coated fabrics was minimal, even after 30 days of immersion.

Silver-enriched microdomain patterns as advanced bactericidal coatings for polymer-based medical devices

Today, it would be difficult for us to live a full life without polymers, especially in medicine, where its applicability is constantly expanding, giving satisfactory results without any harm effects on health. This study focused on the formation of hexagonal domains doped with AgNPs using a KrF excimer laser (λ=248 nm) on the polyetheretherketone (PEEK) surface that acts as an unfailing source of the antibacterial agent - silver. The hexagonal structure was formed with a grid placed in front of the incident laser beam. Surfaces with immobilized silver nanoparticles (AgNPs) were observed by AFM and SEM. Changes in surface chemistry were studied by XPS. To determine the concentration of released Ag+ ions, ICP-MS analysis was used. The antibacterial tests proved the antibacterial efficacy of Ag-doped PEEK composites against Escherichia coli and Staphylococcus aureus as the most common pathogens. Because AgNPs are also known for their strong toxicity, we also included cytotoxicity tests in this study. The findings presented here contribute to the advancement of materials design in the biomedical field, offering a novel starting point for combating bacterial infections through the innovative integration of AgNPs into inert synthetic polymers.

Chitosan/MgO NPs/CQDs bionanocomposite coating: Fabrication, characterization and determination of antimicrobial efficacy

The development of new polymer nanocomposites or antibacterial coatings is crucial in combating drug-resistant infections, particularly bacterial infections. In this study, a new chitosan polymer based nanocomposite reinforced with magnesium oxide nanopowders and carbon quantum dots was fabricated by sol-gel technique and coated on 316 L stainless steel. In order to gaining the optimal amount of components to achieve the maximum antibacterial properties, the effect of concentration of nanocomposite components on its antibacterial properties was investigated. Crystal structure, microstructure, elemental dispersion, size distribution, chemical composition and morphology of nanocomposite and coating were characterized with various analyses. The obtained results exhibited that the carbon quantum dot and magnesium oxide nanopowders were distributed uniformly and without agglomeration in the chitosan matrix and created a uniform coating. The antibacterial properties of the synthesized samples against Staphylococcus aureus bacteria (gram positive) were evaluated using disk diffusion and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) antibacterial tests. The inhibition growth zone formed around the antibiotic and nanocomposite 25 mg/ml under dark and light was about 32 and 14, 11 mm, respectively. Also, MIC and MBC values for final nanocomposite were 62.5 and 125 μg/ml, respectively.

Visible light-responsive all-organic polyurethane antibacterial coatings using a polythiophene derivative

Visible light-responsive all-organic polyurethane antibacterial coatings using a polythiophene derivative

Self-Cleaning Antibacterial Composite Coating of Fluorinated Acrylic Resin and Ag/SiO2 Nanoparticles with Quaternary Ammonium.

With improvements in living standards, the demand for antibacterial self-cleaning coatings has significantly increased. In this work, self-cleaning coatings with antibacterial properties were fabricated by spray-coating a composite of fluorinated acrylic resin and Ag/SiO2 nanoparticles with quaternary ammonium salts. The synergistic action of the quaternary ammonium salts and silver nanostructures caused the coating to show a dual antibacterial effect. The Ag/SiO2 nanoparticles roughened the coating's surface and, in combination with the fluorinated chains, provided the surface a superhydrophobic self-cleaning property with a contact angle of 156° and a sliding angle of less than 2°. Notably, the composite coating withstood 100 abrasion cycles without losing its superhydrophobicity and the contact angle is still exceeded 150° after 60 h of immersion solutions with different pH values, demonstrating outstanding wear resistance and acid/alkali stability. The incorporation of nanostructured antibacterial agents was effective in improving the roughness and antibacterial properties of the low-surface-energy resin, resulting in a self-cleaning antibacterial composite coating. This method may pave a new route for the design of functional coating materials with excellent overall performance.

Soft nanotechnology: Used as a functional coating on a nanostructured germicidal surface

Bacterial contamination has emerged as a significant threat to human health over the past century. Initially, antibiotics were seen as the solution to this problem, but their overuse has led to the development of drug resistance and the rise of superbugs. These superbugs are resistant to most, if not all, conventional antibiotics, making them particularly difficult to treat. Interestingly, research has shown that the wings of dragonflies and cicadas possess natural nanopillar structures that are capable of inhibiting bacterial growth. These nanopillars puncture bacterial cell membranes, leading to bacterial death. This discovery has opened up new avenues for combating bacterial contamination. Recent advancements in soft nanotechnology have introduced innovative antibacterial coatings that are crucial for combating these antibiotic-resistant superbugs. These coatings work by mimicking the nanopillar structures found on the wings of dragonflies and cicadas. Understanding the interaction between bacteria and these nanoantibacterial coatings is essential for achieving effective bactericidal outcomes. Different bacteria require varying optimum aspect ratios, which can be achieved through various formation methods. Therefore, this paper elucidates the principles of soft nanocoating, with a focus on comparing aspect ratios obtained through different preparation techniques and, according to the different aspect ratio, determining the corresponding applicable sterilization scene. It also explores the practical application of nanostructure bactericidal surface coatings to address the growing threat of antibiotic resistance and enhance public health. Moreover, as an emerging field, this paper examines the challenges in soft nanocoating applications and the directions that can be improved in the future. The versatility and potential of soft nanotechnological coatings seems to apply to various industries, promising enhanced performance and safety standards. This is a crucial step towards creating a safer and healthier future for all.

Silver nanoparticle-decorated cellulose beads: Eco-friendly catalysts for efficient 4-nitrophenol reduction and antibacterial performance

This study presents an innovative and environmentally friendly method to produce fibrous cellulose beads by mechanically stirring natural fibers in an aqueous medium. Date palm fibers are transformed into uniform beads with a diameter of 1.5 to 2 mm through chemical treatment and mechanical agitation. These beads are then decorated with silver nanoparticles (Ag0 NPs) in a one-step synthesis, giving them catalytic capabilities for the reduction of 4-nitrophenol (4-NP) and antibacterial activities. Characterization techniques such as FTIR, XRD, SEM, EDX, and TGA confirmed the successful synthesis and deposition of Ag0 NPs on the cellulose beads. Tests showed complete conversion of 4-NP to 4-AP in just 7 min, with pseudo-first-order kinetics and a Kapp of 0.590 min-1. Additionally, Ag0@CB demonstrated exceptional recyclability and stability over five cycles, with minimal silver release. The beads also showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus, effectively eradicating bacterial colonies in 30 min. In summary, Ag0@CB exhibits multifunctional capabilities for degrading organic pollutants and biomedical applications, offering promising potential for large-scale production and practical use in water treatment and antibacterial coatings.

Bioderived Antibacterial Coating for Polypropylene Non-woven Fabric to Prevent Secondary Infection

Bioderived Antibacterial Coating for Polypropylene Non-woven Fabric to Prevent Secondary Infection

Novel Resin-Based Antibacterial Root Surface Coating Material to Combat Dental Caries.

Root caries caused by cariogenic bacteria are a burden on a large number of individuals worldwide, especially the elderly. Applying a protective coating to exposed root surfaces has the potential to inhibit the development of caries, thus preserving natural teeth. This study aimed to develop a novel antibacterial coating to combat root caries and evaluate its effectiveness using the antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM). DMAHDM was synthesized and incorporated into a resin consisting of 55.8% urethane dimethacrylate (UDMA) and 44.2% TEG-DVBE (UV) at a 10% mass fraction of glass filler. Multiple concentrations of DMAHDM were tested for their impact on the resin's mechanical and physical properties. S. mutans biofilms grown on resin disks were analyzed for antibacterial efficacy. Cytotoxicity was assessed against human gingival fibroblasts (HGFs). The results showed an 8-log reduction in colony-forming units (CFUs) against S. mutans biofilm (mean ± sd; n = 6) (p < 0.05) when 5% DMAHDM was incorporated into the UV resin. There was a 90% reduction in metabolic activity and lactic acid production. A low level of cytotoxicity against HGF was observed without compromising the physical and mechanical properties of the resin. This coating material demonstrated promising physical properties, potent antibacterial effects, and low toxicity, suggesting its potential to protect exposed roots from caries in various dental procedures and among elderly individuals with gingival recession.

Antibacterial coatings on magnesium formed via plasma electrolytic oxidation in CuO suspension

Biodegradable materials, especially Magnesium (Mg) and its alloys, are preferred for bone implants due to their compatibility with host tissue and biomechanical support. However, their rapid corrosion and vulnerability to structural failure, compounded by infections from antibiotic-resistant bacteria, pose significant challenges. Addressing these issues, we developed silicate-based composite coatings with varying CuO concentrations (1, 5, and 7 wt%) on Mg using plasma electrolytic oxidation (PEO). This study evaluated the coatings' surface characteristics, degradation behavior, and optimum composition. Our analyses, including XPS and EDX, confirmed the presence and influence of CuO on the coatings. We observed enhanced hydroxyapatite crystallization in CuO-doped coatings, which is critical for implant biocompatibility. These coatings also showed improved corrosion resistance and controlled ion release, likely due to silicate composition and CuO's sealing effects. Antimicrobial assays revealed that CuO concentration influenced bacterial and fungal adhesion, varying with microorganism type. Our findings demonstrate that incorporating inert copper particles into PEO coatings alters their chemical and elemental properties, enhancing bioactivity, corrosion resistance, and antimicrobial efficacy. These multifaceted improvements position our CuO-doped silicate coatings as a pioneering solution in bone implant technology, potentially setting new standards for safety, efficacy, and longevity in orthopedic and dental implants.

Gallium-doped zirconia coatings modulate microbiological outcomes in dental implant surfaces.

Despite the significant recent advances in manufacturing materials supporting advanced dental therapies, peri-implantitis still represents a severe complication in dental implantology. Herein, a sol-gel process is proposed to easily deposit antibacterial zirconia coatings onto bulk zirconia, material, which is becoming very popular for the manufacturing of abutments. The coatings' physicochemical properties were analyzed through x-ray diffraction and scanning electron microscopy-energy-dispersive x-ray spectroscopy investigations, while their stability and wettability were assessed by microscratch testing and static contact angle measurements. Uniform gallium-doped tetragonal zirconia coatings were obtained, featuring optimal mechanical stability and a hydrophilic behavior. The biological investigations pointed out that gallium-doped zirconia coatings: (i) displayed full cytocompatibility toward human gingival fibroblasts; (ii) exhibited significant antimicrobial activity against the Aggregatibacter actinomycetemcomitans pathogen; (iii) were able to preserve the commensal Streptococcus salivarius. Furthermore, the proteomic analyses revealed that the presence of Ga did not impair the normal oral microbiota. Still, interestingly, it decreased by 17% the presence of Fusobacterium nucleatum, a gram-negative, strictly anaerobic bacteria that is naturally present in the gastrointestinal tract. Therefore, this work can provide a valuable starting point for the development of coatings aimed at easily improving zirconia dental implants' performance.

Studying the Effect of Magnetron Copper Deposition on the Surface Topography of Biodegradable Antibacterial Coating.

The surface properties of the materials used significantly influence the success and longevity of medical implants. Increasing surface roughness promotes osteoblast activity and osseointegration, while biodegradable materials such as copper have shown potential for antimicrobial applications. However, the effect of coating parameters on surface topography is not well investigated. Sputtering of copper was performed using EPOS-PVD-440 system (Zeleno-grad, Russia). The samples were examined by Scanning Electron Microscopy (SEM) with subsequent image processing in Mountains software (Digital Surf). Antibacterial efficacy was evaluated against Staphylococcus aureus by measuring the zone of inhibition. Additionally, copper ion release was monitored over time to assess its correlation with changes in surface topography. Higher sputtering currents increased surface roughness and particle size, with a significant release of copper ions within the first 24 hr of immersion. Samples sputtered at higher currents exhibited coarser grain structures. The release of copper ions in the simulated biological environment led to further changes in surface topography, highlighting the critical influence of sputtering parameters on coating properties. Optimizing magnetron copper deposition parameters enhances the surface topography and antibacterial effectiveness of biodegradable coatings on implants.

Advances in Antibacterial Polymer Coatings Synthesized via Chemical Vapor Deposition

Advances in Antibacterial Polymer Coatings Synthesized via Chemical Vapor Deposition