Antibacterial Coatings Research Articles

Silver─Gallium Nano‐Amalgamated Particles as a Novel, Biocompatible Solution for Antibacterial Coatings

AbstractBacterial infections account for countless deaths globally. Antibiotics are the primary countermeasure; however, the alarming spread of antibiotic‐resistant strains necessitates alternative solutions. Silver and silver compounds have emerged as promising antibacterial agents. However, issues related to cytotoxicity and genotoxicity of silver remain concern. To overcome these challenges, this proposes an easy‐to‐control and straightforward method to synthesize novel Silver─gallium (Ag─Ga) nano‐amalgamated particles. Gallium liquid metal (GaLM) is used to facilitate the galvanic deposition of silver nanocrystals (Ag) on oxide layer. The GaLM not only serves as a carrier for silver through the galvanic replacement process, but also provides a controlled‐release mechanism for silver, in this way improving biocompatibility, reducing inflammation, and stimulating bone growth. Notably, Ag─Ga suspensions can be conveniently deposited by spray‐coating on a range of devices and material surfaces, effectively eliminating pathogenic bacteria with efficacy comparable to that of silver ions. In vivo studies in rat models affirm the antibacterial capabilities, especially against methicillin‐resistant Staphylococcus aureus and Escherichia coli, when placed on implants such as titanium rods and magnesium discs. Furthermore, Ag─Ga promotes bone matrix formation and collagen growth without eliciting an inflammatory response, indicating a major promise for coatings on a wide variety of biomedical devices and materials.

Application of in-situ casted ZnO-starch nanocomposite for packaging of strawberries (Fragaria x ananassa)

Nanomaterials have recently been used in packaging as antibacterial coatings because of their desirable antibacterial and antifungal properties. In this study, we describe the synthesis of zinc oxide nanoparticles (ZnO NPs) and evaluate potato peel starch based ZnO NPs nanocomposite paper (ZnO-starch NC paper) on microbiological activity, storage, and properties of strawberries (Fragaria x ananassa). The ZnO-starch NC paper was used to package the strawberries and then stored at 4 °C and 27 °C for 10 days, respectively, controls were incubated without the ZnO-starch NC paper. The ZnO NPs were synthesized and characterized, the formation of sizes ranging from 35 to 40 nm were confirmed by SEM and XRD. The SEM showed that the ZnO NPs were successfully embedded in the starch forming the ZnO-starch NC. The antimicrobial and antifungal analysis showed that the ZnO-starch NC paper was effective against the fungi, B. cinerea, gram positive bacteria, B. subtilis and S. aureus but not against the gram negative bacteria, E. coli and P. aeruginosa. Total phenolic compounds and Vitamin C content of both the ZnO-starch NC packaged and controls were found to be in the normal range of recommended quality parameters of strawberries as there was no change in intrinsic factors of the fruits during incubation. Application of the ZnO-starch NC in packaged strawberries resulted in the reduction of weight loss and microbial growth compared to the controls. The overall weight loss showed that the loss of moisture and nutrients was not statistically significant (p > 0.05). We conclude that the ZnO-starch NC packaging is a promising safe alternative to extend storage period and increase the shelf-life of strawberries.

Comprehensive biosafety assessment of Ag-ZnO/talc nanomaterials: Implications for antibacterial applications

Given the global proliferation of pathogenic microorganisms, there exists a pressing imperative to cultivate efficacious nanomaterials possessing antimicrobial attributes, thereby impeding the transmission of infectious diseases. Clay-based nanoparticles, due to their inherent properties, serve as optimal candidates for the creation of innovative antimicrobial agents, particularly for coating materials. In this study, ZnO nanoparticles were synthesized on talc surfaces and doped with Ag+, yielding an effective antimicrobial composite (Ag-ZnO/talc). The primary aim was to comprehensively evaluate the antimicrobial effectiveness, material compatibility, and biosafety of Ag-ZnO/talc, as well as its potential applications in antibacterial coatings. The finding underscored the remarkable antibacterial properties of Ag-ZnO/talc composites, chiefly through the generation of reactive oxygen species, leading to impairment of the bacterial membrane and leakage of nucleic acid content. A biosafety evaluation indicated minimal cytotoxicity, a low hemolysis rate, and negligible skin tissue reactions, thereby suggesting its suitability for human application. Furthermore, the incorporation of the antimicrobial agent Ag-ZnO/talc did not significantly alter the physicochemical characteristics of the coating, while maintaining an enduring antimicrobial effect for a duration of two months. These findings establish the potential of clay-based antimicrobials for effective and safe application in coatings, facilitating the development of antimicrobial coatings in diverse industrial and public health environments.

X-ray and UV Irradiation-Induced Reactive Oxygen Species Mediated Antibacterial Activity in Fe and Pt Nanoparticle-Decorated Si-Doped TiCaCON Films.

Bone implants with biocompatibility and the ability to biomineralize and suppress infection are in high demand. The occurrence of early infections after implant placement often leads to repeated surgical treatment due to the ineffectiveness of antibiotic therapy. Therefore, an extremely attractive solution to this problem would be the ability to initiate bacterial protection of the implant by an external influence. Here, we present a proof-of-concept study based on the generation of reactive oxygen species (ROS) by the implant surface in response to X-ray irradiation, including through a layer of 3 mm adipose tissue, providing bactericidal protection. The effect of UV and X-ray irradiation of the implant surface on the ROS formation and the associated bactericidal activity was compared. The focus of our study was light-sensitive Si-doped TiCaCON films decorated with Fe and Pt nanoparticles (NPs) with photoinduced antibacterial activity mediated by ROS. In the visible and infrared range of 300-1600 nm, the films absorb more than 60% of the incident light. The high light absorption capacity of TiO2/TiC and TiO2/TiN heterostructures was demonstrated by density functional theory calculations. After short-term (5-10 s) low-dose X-ray irradiation, the films generated significantly more ROS than after UV illumination for 1 h. The Fe/TiCaCON-Si films showed enhanced biomineralization capacity, superior cytocompatibility, and excellent antibacterial activity against multidrug-resistant hospital Escherichia coli U20 and K261 strains and methicillin-resistant Staphylococcus aureus MW2 strain. Our study clearly demonstrates that oxidized Fe NPs are a promising alternative to the widely used Ag NPs in antibacterial coatings, and X-rays can potentially be used in ROS-regulating therapy to suppress inflammation in case of postimplant complications.

Antibacterial Activity Edible Coating of Jackfruit Seed Starch and Alginate Incorporated with ZnO Nanoparticles Applied to Cherry Tomatoes

Cherry tomatoes have many health benefits and have high economic value. However, cherry tomatoes are perishable and short lived. To protect and maintain the quality of cherry tomatoes, you can apply an edible coating. The materials used in this study were jackfruit seed starch, alginate, and ZnO nanoparticles. This study aims to determine the effect of edible coating on jackfruit seed starch and alginate incorporating ZnO nanoparticles applied to cherry tomatoes in terms of antibacterial activity and shelf life. Variations in the treatment in this study were edible coating materials for jackfruit seed starch and alginate, and the concentration of ZnO nanoparticles (0%; 5%; 10%; 15%). Antibacterial activity was analyzed against E. coli and S. aureus bacteria. The results showed that the edible coating of jackfruit seed starch with 10% and 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, while the 5%, 10%, and 15% ZnO nanoparticle variations were able to form an inhibition zone against S bacteria. aureus. In edible coating alginate with 15% ZnO nanoparticles incorporation was able to form an inhibition zone against E. coli bacteria, whereas in all variations of ZnO nanoparticles it was able to form an inhibition zone against S. aureus bacteria. The addition of ZnO nanoparticles proved the formation of a larger bacterial inhibition zone compared to edible coatings without ZnO nanoparticles. The results also showed that cherry tomatoes coated with an edible coating of jackfruit seed starch and alginate with a variation of ZnO nanoparticles had a longer shelf life compared to cherry tomatoes that were not coated with an edible coating.

Preparation, Properties, and Bioapplications of Block Copolymer Nanopatterns.

Block copolymer (BCP) self-assembly has emerged as a feasible method for large-scale fabrication with remarkable precision - features that are not common for most of the nanofabrication techniques. In this review, recent advancements in the molecular design of BCP along with state-of-the-art processing methodologies based on microphase separation alone or its combination with different lithography methods are presented. Furthermore, the bioapplications of the generated nanopatterns in the development of protein arrays, cell-selective surfaces, and antibacterial coatings are explored. Finally, the current challenges in the field are outlined and the potential breakthroughs that can be achieved by adopting BCP approaches already applied in the fabrication of electronic devices are discussed.

Laser-assisted direct coating of Graphene-Based films on plastic substrates with bactericidal properties

Bacterial growth on surfaces is a substantial problem in medical equipment, fresh food storage, and water supply industries. Antibacterial coatings offer a preferred method to prevent this dangerous hazard. However, to provide a complete solution, the developed coating must not only efficiently prevent bacterial growth and consist of cost-effective, stable, and bio-friendly materials but also offer a simple coating method. In this work, we use novel laser processing that offers significant advancements, including (1) fast, single-step, and waste-free synthesis, (2) allowing direct printing of graphene over any substrate, including thermal-sensitive materials (i.e., polymers), and (3) micron-resolution patterning of the coated materials. We use an intense laser beam to fabricate metal-oxide/graphene nanoparticle composite films directly on plastic surfaces. The metal-oxide nanoparticles (cobalt and copper) are tested for antibacterial activity. Due to the combined formation, the metal-oxide nanoparticles are highly dispersed and firmly adhered to the graphene matrix. Notably, the structure and properties of the laser product, such as the nanoparticle's size and the graphitization level, can be controlled by tuning laser parameters. The composite coatings demonstrate excellent antibacterial activity. Studying substrates coated with different metal compositions found that 4.5–5 % of metal contents have antibacterial activity (percentage inhibition) by 89 % (PBS). Additionally, leaching studies demonstrate that the fabricated substrates are stable in different pH solutions.

Preparation of zinc nanooxide and its application for antibacterial coatings

Preparation of zinc nanooxide and its application for antibacterial coatings

Antibacterial Calcium Phosphate Coatings for Biomedical Applications Fabricated via Micro-Arc Oxidation.

A promising method for improving the functional properties of calcium-phosphate coatings is the incorporation of various antibacterial additives into their structure. The microbial contamination of a superficial wound is inevitable, even if the rules of asepsis and antisepsis are optimally applied. One of the main problems is that bacteria often become resistant to antibiotics over time. However, this does not apply to certain elements, chemical compounds and drugs with antimicrobial properties. In this study, the fabrication and properties of zinc-containing calcium-phosphate coatings that were formed via micro-arc oxidation from three different electrolyte solutions are investigated. The first electrolyte is based on calcium oxide, the second on hydroxyapatite and the third on calcium acetate. By adding zinc oxide to the three electrolyte solutions, antibacterial properties of the coatings are achieved. Although the same amount of zinc oxide has been added to each electrolyte solution, the zinc concentration in the coatings obtained vary greatly. Furthermore, this study investigates the morphology, structure and chemical composition of the coatings. The antibacterial properties of the zinc-containing coatings were tested toward three strains of bacteria-Staphylococcus aureus, methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Coatings of calcium acetate and zinc oxide contained the highest amount of zinc and displayed the highest zinc release. Moreover, coatings containing hydroxyapatite and zinc oxide show the highest antibacterial activity toward Pseudomonas aeruginosa, and coatings containing calcium acetate and zinc oxide show the highest antibacterial activities toward Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

Antibacterial Matte Glass-Ceramic Coatings with Satin Texture for Ceramic Tiles

Antibacterial satin glass-ceramic coatings for ceramic tiles have been developed by one-stage firing on the basis of high-calcium zinc aluminum silicate frits, which are modified with heavy metal cations. The antibacterial effect of the developed matte glass-ceramic coatings with a satin texture was established due to the effect of potentiating the antibacterial activity of the combined action of the hardystonite crystalline phase and fillers of zinc and tin oxides.

Cytocompatibility, antibacterial, and corrosion properties of chitosan/polymethacrylates and chitosan/poly(4-vinylpyridine) smart coatings, electrophoretically deposited on nanosilver-decorated titania nanotubes.

The development of novel implants subjected to surface modification to achieve high osteointegration properties at simultaneous antimicrobial activity is a highly current problem. This study involved different surface treatments of titanium surface, mainly by electrochemical oxidation to produce a nanotubular oxide layer (TNTs), a subsequent electrochemical reduction of silver nitrate and decoration of a nanotubular surface with silver nanoparticles (AgNPs), and finally electrophoretic deposition (EPD) of a composite of chitosan (CS) and either polymethacrylate-based copolymer Eudragit E 100 (EE100) or poly(4-vinylpyridine) (P4VP) coating. The effects of each stage of this multi-step modification were examined in terms of morphology, roughness, wettability, corrosion resistance, coating-substrate adhesion, antibacterial properties, and osteoblast cell adhesion and proliferation. The results showed that the titanium surface formed nanotubes (inner diameter of 97 ± 12 nm, length of 342 ± 36 nm) subsequently covered with silver nanoparticles (with a diameter of 88 ± 8 nm). Further, the silver-decorated nanotubes were tightly coated with biopolymer films. Most of the applied modifications increased both the roughness and the surface contact angle of the samples. The deposition of biopolymer coatings resulted in reduced burst release of silver. The coated samples revealed potent antimicrobial activity against both Gram-positive and Gram-negative bacteria. Total elimination (99.9%) of E. coli was recorded for a sample with CS/P4VP coating. Cytotoxicity results using hFOB 1.19, a human osteoblast cell line, showed that after 3 days the tested modifications did not affect the cellular growth according to the titanium control. The proposed innovative multilayer antibacterial coatings can be successful for titanium implants as effective postoperative anti-inflammation protection.

Surface Grafted N‐Oxides have Low‐Fouling and Antibacterial Properties

AbstractLow‐fouling materials are often generated by surface zwitterionization with polymers. In this context, poly‐N‐oxides have recently attracted considerable attention as biomimetic stealth coatings with low protein adsorption. Herein, this study reports that poly‐N‐oxides can be grafted from plasma‐activated plastic base materials. The resulting hydrophilic surfaces have low‐fouling properties in bacterial suspensions and suppress the formation of biofilms. Moreover, efficient antibacterial activity against Gram‐negative and Gram‐positive bacteria caused by release of reactive oxygen species is observed. The latter effect is specific for polymeric N‐oxides and is most likely triggered by a reductive activation of the N‐oxide functionality in the presence of bacteria. In contrast to other zwitterionic polymers, N‐oxides combine thus low‐fouling (stealth) properties with antibacterial activity. The bioactive N‐oxide groups can be regenerated after use by common oxidative disinfectants. Poly‐N‐oxides are thus attractive antibacterial coatings for many base materials with a unique combined mechanism of action.

A Remineralizing and Antibacterial Coating for Arresting Caries.

Dental caries is a dynamic disease induced by the unbalance between demineralization of dental hard tissues caused by biofilm and remineralization of them; however, although various effective remineralization methods have been well documented, it is a challenge to reestablish the balance by enhancing remineralization alone while ignoring the antibacterial therapy. Therefore, the integration of remineralizing and antibacterial technologies offers a promising strategy to halt natural caries progression in clinical practice. Here, the conception of interrupting dental caries (IDC) was proposed based on the development of dual-functional coating with remineralizing and antibacterial properties. In this study, bovine serum albumin (BSA) loaded octenidine (OCT) successfully to form a BSA-OCT composite. Subsequently, through fast amyloid-like aggregation, the phase-transited BSA-OCT (PTB-OCT) coating can be covered on teeth, resin composite, or sealant surfaces in 30 min by a simple smearing process. The PTB-OCT coating showed satisfactory effects in promoting the remineralization of demineralized enamel and dentin in vitro. Moreover, this coating also exerted significant acid-resistance stability and anti-biofilm properties. Equally importantly, this coating exhibited promising abilities in reducing the microleakage between the tooth and resin composite in vitro and preventing primary and secondary caries in vivo. In conclusion, this novel dual-functional PTB-OCT coating could reestablish the balance between demineralization and remineralization in the process of caries, thereby potentially preventing or arresting caries.

Antibacterial Properties of AquaSun Sol–Gel Coating

The antimicrobial activity, surface features, wettability, and adhesion of photocatalytic xerogel AquaSun deposited on shipbuilding steel in comparison to those of a commercial antifouling paint are investigated. The antimicrobial activity of AquaSun deposited on a steel substrate pretreated with primer and tiecoat paint exposed to a microbial consortium composed of Bacillus aquimaris and Pseudomonas poae is significant and of broad scope. Taking into account the low cost, high stability, and lack of ecotoxicity of this hybrid sol–gel coating, these results are promising en route to developing novel antibacterial coatings of broad applicability.

Washing resistant antibacterial composite coatings on cotton textiles

Washing resistant antibacterial composite coatings on cotton textiles

Polysaccharide-based antibacterial coating technologies.

To tackle antimicrobial resistance, a global threat identified by the United Nations, is a common cause of healthcare-associated infections (HAI) and is responsible for significant costs on healthcare systems, a substantial amount of research has been devoted to developing polysaccharide-based strategies that prevent bacterial attachment and biofilm formation on surfaces. Polysaccharides are essential building blocks for life and an abundant renewable resource that have attracted much attention due to their intrinsic remarkable biological potential antibacterial activities. If converted into efficient antibacterial coatings that could be applied to a broad range of surfaces and applications, polysaccharide-based coatings could have a significant potential global impact. However, the ultimate success of polysaccharide-based antibacterial materials will be determined by their potential for use in manufacturing processes that are scalable, versatile, and affordable. Therefore, in this review we focus on recent advances in polysaccharide-based antibacterial coatings from the perspective of fabrication methods. We first provide an overview of strategies for designing polysaccharide-based antimicrobial formulations and methods to assess the antibacterial properties of coatings. Recent advances on manufacturing polysaccharide-based coatings using some of the most common polysaccharides and fabrication methods are then detailed, followed by a critical comparative overview of associated challenges and opportunities for future developments. STATEMENT OF SIGNIFICANCE: Our review presents a timely perspective by being the first review in the field to focus on advances on polysaccharide-based antibacterial coatings from the perspective of fabrication methods along with an overview of strategies for designing polysaccharide-based antimicrobial formulations, methods to assess the antibacterial properties of coatings as well as a critical comparative overview of associated challenges and opportunities for future developments. Meanwhile this work is specifically targeted at an audience focused on featuring critical information and guidelines for developing polysaccharide-based coatings. Including such a complementary work in the journal could lead to further developments on polysaccharide antibacterial applications.

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.