Antibacterial Coatings Research Articles

Farsi gum (zedo gum) coating incorporated with Lactobacillus sakei; a novel shelf-life extension for Turkey breast during refrigerated storage

Antioxidant and antibacterial coatings incorporated with biological agents are an emerging alternative for preserving meat products. In this study, Farsi gum-based coatings (FG) incorporated with Latilactobacillus sakei were used for the shelf-life extension of refrigerated turkey breast. The quality and safety properties of coated turkey breast were investigated during storage at refrigeration temperature. Results revealed that L. sakei loading into the FG coating could significantly (p < 0.05) improve the quality of turkey breast in a 16-day refrigerated storage. The increase in the values of pH (6.15–6.94), total volatile basic-nitrogen (TVB-N) (34.33–43.13 mg N/100 g), thiobarbituric acid reactive substances (TBARs) (2.27–3.67 mg MDA/kg), and protein carbonyl (PC) (1.62–2.14 nmol/mg protein) of samples during cold storage periods was as follows: FG 2% + L. Sakei < FG 1% + L. Sakei < FG 2% < FG 1% < uncoated (control). The microbial quality of turkey breast showed a significant (p < 0.05) improvement in the presence of the L. sakei coatings, ranging from 7.15 to 7.75 log10 CFU/g in different treatments. The texture, odor, color, and overall acceptability of the coated turkey breast samples were significantly (p < 0.05) more desirable than the uncoated turkey breast samples. The findings revealed that FG coating incorporated with L.sakei can improve turkey breast's shelf-life by reducing microbial growth and adverse chemical reactions.

Investigation of Antibacterial Coatings Based on Chitosan/Polyacrylic Acid/Chlorhexidine for Orthopedic Implants

Investigation of Antibacterial Coatings Based on Chitosan/Polyacrylic Acid/Chlorhexidine for Orthopedic Implants

Cationic 4-Vinylpyridine Copolymer Nanospheres with Dual Active Centers for Antibacterial Coatings

Cationic 4-Vinylpyridine Copolymer Nanospheres with Dual Active Centers for Antibacterial Coatings

Fabrication of smart nanogel based on carrageenan and green coffee extract as a long-term antifouling agent to improve biofilm prevention in food production

This study investigates the extract of the bioactive compounds from green coffee extract (GCE) and the loading of two different concentrations of GCE (1% and 2%) onto carrageenan nanogels (CAR NGs) to compare their antibacterial and antibiofilm effects with unloaded nanogels (NGs). The bioactive compounds of GCE were characterized using GC–MS analysis. The GCE1 and GCE2 were successfully deposited onto the surface of CAR NGs. The antibacterial and antibiofilm potential of prepared NGs were conducted against some foodborne pathogens (E. coli O157, Salmonella enterica, Staphylococcus aureus, and Listeria monocytogenes). The results of GC–MS analysis indicated that there were identified 16 bioactive compounds in GCE, including caffeine (36.27%), Dodemorph (9.04%), and D-Glycero-d-ido-heptose (2.44%), contributing to its antimicrobial properties. The antibacterial coatings demonstrated a notable antimicrobial effect, showing zone of inhibition (ZOI) diameters of up to 37 mm for GCE2 loaded CAR NGs. The minimum inhibitory concentration (MIC) values for GCE2 loaded CAR NGs were 80 ppm for E. coli O157, and 120 ppm for S. enterica, S. aureus, and L. monocytogenes, achieving complete bacterial inactivation within 10–15 min of exposure. Both GCE1 and GCE2 loaded CAR NGs significantly reduced biofilm cell densities on stainless steel (SS) materials for E. coli O157, S. enterica, S. aureus, and L. monocytogenes, with reductions ranging from 60% to 95%. Specifically, biofilm densities were reduced by up to 95% for E. coli O157, 89% for S. enterica, 85% for S. aureus, and 80% for L. monocytogenes. Results of the toxicity evaluation indicated that the NGs were non-toxic and biocompatible, with predicted EC50 values proved their biocompatibility and safety. These results recommended that GCE loaded CAR NGs are promising as natural antimicrobial agents for enhancing food safety and extending shelf life. Further, the study concluded that incorporating GCE into CAR NGs is an effective strategy for developing sustainable antimicrobial coatings for the food industry and manufacturing.

A scalable and universal strategy for constructing long-term antibacterial coatings with lubricant property on medical catheters

Medical catheters might cause a high morbidity of catheter-associated urinary tract infections (CAUTIs) because of the bacterial adhesion onto the surface. In addition, the inherent hydrophobicity of catheter materials exacerbates mechanical friction, leading to tissue damage. Therefore, coatings with integrated antibacterial and lubricative properties are appealing approaches to mitigate these challenges. In this study, a kind of polyurethane (PU)-based coatings were developed and prepared on medical catheters, which were modified with a cationic antibacterial agent, quaternized ammonium-modified methyldiethanolamines (QMDEAs). Due to the reaction among castor oil tertiary alcohols, isocyanates and QMDEAs, a polymer cross-linked network was fabricated, in which a hydrophilic polymer, polyvinylpyrrolidone (PVP), was added to form a semi-interpenetrating network. The structures of the coatings were regulated by adjusting the lengths of alkyl chain of QMDEAs, concentrations of pre-coated solutions, ratios of QMDEA:isocyanate, and parameters of preparation process. Among the coatings we prepared, PU-C10–46 possessed the optimized performances, which reduced the dynamic friction coefficient by 91.38 % and had the antibacterial efficiency of 99.9 % with good biocompatibility. The in vivo anti-infective properties of PU-C10–46 were also demonstrated by an infected animal model. Furthermore, PU-C10–46 was produced in an industrial equipment, and the large-scaled industrial products also had the same performances. This work could provide a promising strategy to deal with the challenges of medical catheter-associated infection.

Effect of Microcapsules of Chitosan-Coated Toddalia asiatica (L.) Lam Extracts on the Surface Coating Properties of Poplar Wood

Using chitosan as the shell material and Toddalia asiatica (L.) Lam extract as the core material, microcapsules of chitosan-coated Toddalia asiatica (L.) Lam extracts were prepared. The microcapsules were added to waterborne topcoats to investigate the effects of different content and MToddalia asiatica(L.) Lam extracts:Mchitosan (MT:MC) on the performance of waterborne coatings on poplar surfaces. Under different MT:MC of microcapsules, the content of microcapsules in the coating was negatively correlated with the glossiness, reflectivity, and adhesion of the coating. The addition of microcapsules reduced the liquid resistance of the coating to citric acid and improved the ethanol and cleaning agent resistance of the coating. The hardness, impact resistance, and roughness of the coatings increased gradually with the increase in microcapsule content. The content of microcapsules was positively correlated with the Escherichia coli and Staphylococcus aureus antibacterial performance of coatings, and the coatings had a slightly higher antibacterial rate against Staphylococcus aureus than Escherichia coli overall. The poplar surface coating with 5.0% microcapsules and MT:MC of 4.0:1 was excellent: the gloss was 5.30 GU, the light loss rate was 62.22%, the color difference ΔE was 22.93, the hardness was HB, the impact resistance was grade 3, the adhesion was grade 2, the roughness was 2.022 µm, the resistance to ethanol and cleaning agent was grade 2, and the resistances to Escherichia coli and Staphylococcus aureus were 74.21% and 82.01%, respectively. The results of the study provide a technical reference for the application of antibacterial waterborne coatings on wood surfaces.

On-demand bactericidal and self-adaptive antifouling hydrogels for self-healing and lubricant coatings of catheters

Catheter-related infections are one of the most common nosocomial infections with increasing morbidity and mortality, and robust antibacterial or antifouling catheter coatings remain great challenges for long-term implantation. Herein, multifunctional hydrogel coatings were developed to provide persistent and self-adaptive antifouling and antibacterial effects with self-healing and lubricant capabilities. Polyvinyl alcohol (PVA) with β-cyclodextrin (β-CD) grafts (PVA-Cd) and 4-arm polyethylene glycol (PEG) with adamantane and quaternary ammonium compound (QAC) terminals (QA-PEG-Ad) were crosslinked through host-guest recognitions between adamantane and β-CD moieties to acquire PVEQ coatings. In response to bacterial infections, QACs exhibit reversible transformation between zwitterions (pH 7.4) and cationic lactones (pH 5.5) to generate on-demand bactericidal effect. Highly hydrophilic PEG/PVA backbones and zwitterionic QACs build a lubricate surface and decrease the friction coefficient 10 times compared with that of bare catheters. The antifouling hydrated layer significantly inhibits blood protein adsorption and platelet activation and reveals negligible hemolysis and cytotoxicity. The dynamic host-guest crosslinking achieves full self-healing of cracks in PVEQ hydrogels, and the mechanical profiles were recovered to over 90 % after rejuvenating the broken hydrogels, exhibiting a long-term stability after mechanical stretching, twisting, knotting and compression. After subcutaneous implantation and local bacterial infection, the retrieved PVEQ-coated catheters display no tissue adhesion and 3 log folds lower bacterial number than that of bare catheters. PVEQ coatings effectively prevent the repeated bacterial infections and there are few inflammatory reactions in the surrounding tissue, while substantial lymphoid infiltration and inflammatory cell aggregation occur in muscle tissues around the bare catheter. Thus, this study demonstrates a catheter coating strategy by on-demand bactericidal, self-adaptive antifouling, self-healing and lubricant hydrogels to address medical devices-related infections. Statement of significanceIt is estimated over two billion peripheral intravenous catheters are annually used in hospitals around the world, and catheter-associated infection has become a great clinical challenge with rapidly rising morbidity and mortality. Surface coating is considered a promising approach, but substantial challenges remain in the development of coatings that simultaneously satisfy both anti-fouling and antibacterial attributes. Even more, few attempts have been made to design mechanically robust coatings and reversible antibacterial or antifouling capabilities, which are critical for long-term medical implants. To address these challenges, we propose a concise strategy to develop hydrogel coatings from commercially available poly(ethylene glycol) and polyvinyl alcohol. In addition to self-healing and lubricant capabilities, the reversible conversion between zwitterionic and cationic lactones of quaternary ammonium compounds enables on-demand bactericidal and self-adaptive antifouling effects.

Silver─Gallium Nano‐Amalgamated Particles as a Novel, Biocompatible Solution for Antibacterial Coatings (Adv. Funct. Mater. 31/2024)

Silver─Gallium Nano‐Amalgamated Particles as a Novel, Biocompatible Solution for Antibacterial Coatings (Adv. Funct. Mater. 31/2024)

Antibacterial Iodine-Releasing Coatings of Cross-Linked Poly(N-vinylpyrrolidone) Synthesized by Solvent-Free Initiated Chemical Vapor Deposition.

Biomaterial-associated infections caused by bacteria pose a great threat to human health, and therefore, various antibacterial coatings have been developed to control bacterial infections. Povidone iodine (PVP-I) is a broad-spectrum antimicrobial agent without drug resistance to most pathogenic microorganisms and has been widely used in the clinic. However, its applications in the field of coatings are limited due to its strong water solubility. Here, we used initiated Chemical Vapor Deposition (iCVD) technique to synthesize cross-linked poly(N-vinylpyrrolidone-co-ethylene glycol dimethacrylate) (PVE) coatings to firmly immobilize poly(N-vinylpyrrolidone) (PVP) on surfaces. After complexation with iodine, PVE-I coatings exhibited potent bacteria-killing and antifouling activities against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus in vitro owing to the antibacterial effect of iodine and the hydrophilicity of VP, respectively. The killing and antifouling effects were positively correlated with the VP content. The PVE-I-2 coating displayed excellent anti-infection performance in a rat subcutaneous implantation model in vivo. This study provided a simple method for preparing stable povidone iodine coatings on surfaces via solvent-free iCVD, and combined bacteria-killing and antifouling strategies to fabricate multifunctional antibacterial coatings against bacterial infections on biomaterial surfaces.

Ultrathin Polyelectrolyte Multilayer Films with Silver Nanoparticles as a Potential Antibacterial Coating

Silv er nanoparticles (AgNPs) are already used as antibacterial agents for medical devices and food packaging materials. However, concerns about its toxicity still exist. AgNPs can be incorporated into ultrathin polyelectrolyte multilayer (PEM) films to minimize this risk. With PEMs, full surface coverage can be achieved with minimal AgNPs, minimizing human exposure. In this study, a simple protocol to fabricate ultrathin PEM/AgNP films using sodium ascorbate as a reductant was developed. The effects of the number of bilayers and ionic strength (0.05 to 0.50 M) on film thickness and amount of AgNPs were investigated. UV/VIS spectra show that increasing the number of bilayers from 1 to 5 would lead to a corresponding increase in film thickness and amount of synthesized AgNPs. Thicker layers and more AgNPs were deposited when the films were fabricated under higher ionic strengths. Films with thicknesses ranging from 15.67 to 87.13 nm were fabricated. The sizes of the incorporated AgNPs were between 54.32 and 259.26 nm, as characterized by scanning electron microscopy. All films were stable when submerged in water for 240 h, suggesting the migration of Ag/Ag+ from the films was minimal. The antibacterial efficacy of the films against Staphylococcus aureus was also assessed. Only the PEM/AgNP films fabricated with the highest salt concentration (0.50 M) showed antibacterial activity under resazurin assay. However, the Kirby Bauer method showed inhibition zones for all films fabricated under all salt concentrations, indicating antibacterial activity at the interface of the bacterial lawn and the films, even with the slow migration of Ag/Ag+. Thus, PEM/AgNP films have the potential to be used as an antibacterial coating.

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 &gt; 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.