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The study showcases findings from an investigation into the chemical composition and morphology of nanocomposite materials employed in the production of dental implants. By utilizing clinical strains of microorganisms isolated from patients with implant infections (including Bacteroides fragilis, Porphyromonas melaninogenica, Actinomyces spp., and Staphylococcus aureus), the authors of the paper analyze the results of the dynamics of biofilm formation on the composite's surface. To minimize complications following surgical procedures in dentistry, the recommendations on the most advantageous research algorithm for composite materials are provided. The implications of these findings extend to the broader field of biomaterials, emphasizing the significance of a meticulous examination of the chemical and morphological attributes for enhancing the long-term success and safety of dental implants. This comprehensive approach addresses immediate concerns related to biofilm formation and provides a foundation for developing more resilient and biocompatible materials in dental prosthetics. [ABSTRACT FROM AUTHOR]

Among the challenges posed by the COVID-19 pandemic, significant efforts have been undertaken to develop antimicrobial/antiviral surfaces by exploiting coating solutions. In this article, we review the actions undertaken by the EU project MIRIA, the main one being the reduction of pathogen transmission on high-traffic surfaces in public and healthcare environments. The project implements several synergies from key antimicrobial/antiviral element selection to the grafting of complex-shaped surfaces. The focus is given to one of the project's key strategies: the adoption of sol-gel technology, known for its efficiency in creating versatile, cost-effective coatings suitable for a wide range of substrates. The project rigorously tests the coatings in simulated environments, such as operating theatres, ensuring their effectiveness and safety. This includes comprehensive durability testing against environmental, chemical, and mechanical stresses, guaranteeing the coatings' long-term functionality. MIRIA's validation process encompasses antibacterial, antifungal, and antiviral testing in line with international standards, confirming their broad-spectrum pathogen resistance. Along with this overview, the impact of the initiative is elucidated, extending beyond healthcare, enhancing public health, creating safer living, and working environments, and reducing economic losses due to illness. To this, the MIRIA project is expected to significantly contribute to the European research and innovation in antimicrobial coatings, addressing challenges like scalability and efficacy against various pathogens. The emphasis on sustainable synthesis, including bio-based materials which align with ecological goals, positions MIRIA as a pivotal initiative in enhancing health safety standards and resilience across Europe. Highlights: The MIRIA project goal is to avoid cross contamination in high traffic objects in the health field. The strategy is the development of 99.99% effective antimicrobial nanocoatings. MIRIA makes use of sol-gel for its versatility on multiple surfaces and on-site application. Standardized testing will ensure non-toxic, antimicrobial and durability properties. One of the pathogens considered is COVID-19, to enhance readiness for future pandemics. [ABSTRACT FROM AUTHOR]

The significance of Pantoea agglomerans bacteria in diseases linked to healthcare is underappreciated due to a shortage of information on their spread. This is the first study in Saudi Arabia to examine the possible contribution of medical students' cell phones (CPs) to the transmission of P. agglomerans to hospitalized patients and to evaluate their antibiotic susceptibility profiles. In total, 250 CPs were swabbed. P. agglomerans was isolated and identified using standard techniques. The suspected colonies were confirmed by the Vitek 2 compact system. The isolates' antimicrobial susceptibility profiles were assessed using Epsilon assays, and the results were interpreted according to Clinical and Laboratory Standards Institute guidelines. The frequency of P. agglomerans contamination of CPs was found to be relatively high (20.40%; 51 isolates/250 samples). Many isolates showed varying degrees of reduced sensitivity to ampicillin, aztreonam, cefazolin, cefotaxime, cefuroxime, and ertapenem antibiotics. To implement optimal infection prevention and control policies regarding the possibility of antibiotic-resistant P. agglomerans transmission through medical students' contact points with hospitalized patients during their frequent activities in healthcare settings, health policymakers may find value in utilizing this study's results. [ABSTRACT FROM AUTHOR]

Introduction: Topographic surface patterning in the micro- and nanometer scale has evolved into a well applied approach in surface functionalization following biomimetic blueprints from nature. Depending on the production process an additional impact of process-related substrate modification has to be considered in functional surface optimization. This is especially true in case of antimicrobial applications of Cu surfaces where a modification of the substrate properties might impact bactericidal efficiency. Methods: In this regard, the effect of ultrashort pulsed direct laser interference patterning on the microstructure of pure Cu and resulting antimicrobial properties was investigated alongside line-like patterning in the scale of single bacterial cells. Results and Discussion: The process-induced microstructure modification was shown to play an important role in corrosion processes on Cu surfaces in saline environment, whereas the superficial microstructure impacts both corrosive interaction and ion emission. Surprisingly, antimicrobial efficiency is not predominantly following deviating trends in Cu ion release rates but rather depends on surface topography and wettability, which was shown to be impacted by the substrate microstructure state, as well. This highlights the need of an in-depth understanding on how different surface properties are simultaneously modulated during laser processing and how their interaction has to be designed to acquire an effective surface optimization e.g., to agitate active antimicrobial surface functionalization. [ABSTRACT FROM AUTHOR]

Synthetic polymer surfaces provide an excellent opportunity for developing materials with inherent antimicrobial and/or biocidal activity, therefore representing an answer to the increasing demand for antimicrobial active medical devices. So far, biologists and material scientists have identified a few features of bacterial cells that can be strategically exploited to make polymers inherently antimicrobial. One of these is represented by the introduction of cationic charges that act by killing or deactivating bacteria by interaction with the negatively charged parts of their cell envelope (lipopolysaccharides, peptidoglycan, and membrane lipids). Among the possible cationic functionalities, the antimicrobial activity of polymers with quaternary ammonium centers (QACs) has been widely used for both soluble macromolecules and non-soluble materials. Unfortunately, most information is still unknown on the biological mechanism of action of QACs, a fundamental requirement for designing polymers with higher antimicrobial efficiency and possibly very low toxicity. This mini-review focuses on surfaces based on synthetic polymers with inherently antimicrobial activity due to QACs. It will discuss their synthesis, their antimicrobial activity, and studies carried out so far on their mechanism of action. [ABSTRACT FROM AUTHOR]

The significance of Pantoea agglomerans bacteria in diseases linked to healthcare is underappreciated due to a shortage of information on their spread. This is the first study in Saudi Arabia to examine the possible contribution of medical students’ cell phones (CPs) to the transmission of P. agglomerans to hospitalized patients and to evaluate their antibiotic susceptibility profiles. In total, 250 CPs were swabbed. P. agglomerans was isolated and identified using standard techniques. The suspected colonies were confirmed by the Vitek 2 compact system. The isolates’ antimicrobial susceptibility profiles were assessed using Epsilon assays, and the results were interpreted according to Clinical and Laboratory Standards Institute guidelines. The frequency of P. agglomerans contamination of CPs was found to be relatively high (20.40%; 51 isolates/250 samples). Many isolates showed varying degrees of reduced sensitivity to ampicillin, aztreonam, cefazolin, cefotaxime, cefuroxime, and ertapenem antibiotics. To implement optimal infection prevention and control policies regarding the possibility of antibiotic-resistant P. agglomerans transmission through medical students’ contact points with hospitalized patients during their frequent activities in healthcare settings, health policymakers may find value in utilizing this study’s results.

Introduction: Topographic surface patterning in the micro- and nanometer scale has evolved into a well applied approach in surface functionalization following biomimetic blueprints from nature. Depending on the production process an additional impact of process-related substrate modification has to be considered in functional surface optimization. This is especially true in case of antimicrobial applications of Cu surfaces where a modification of the substrate properties might impact bactericidal efficiency.Methods: In this regard, the effect of ultrashort pulsed direct laser interference patterning on the microstructure of pure Cu and resulting antimicrobial properties was investigated alongside line-like patterning in the scale of single bacterial cells.Results and Discussion: The process-induced microstructure modification was shown to play an important role in corrosion processes on Cu surfaces in saline environment, whereas the superficial microstructure impacts both corrosive interaction and ion emission. Surprisingly, antimicrobial efficiency is not predominantly following deviating trends in Cu ion release rates but rather depends on surface topography and wettability, which was shown to be impacted by the substrate microstructure state, as well. This highlights the need of an in-depth understanding on how different surface properties are simultaneously modulated during laser processing and how their interaction has to be designed to acquire an effective surface optimization e.g., to agitate active antimicrobial surface functionalization.

Today, one of the biggest challenges is infections in the painted walls of hospitals. Acrylic-based paints are a target of antibiotic-resistant microorganisms since they contain cellulosic compounds as thickeners. The aim of this study was to synthesize and investigate the biocidal activity and toxicity of heterophase ZnO-Ag nanoparticles fixed in water-based acrylic paint layers in reference to a nontreated water-based paint. The ZnO-Ag nanoparticles with average particle sizes of about 80 nm were simply obtained by electrical explosion of two twisted wires in an oxygen-containing atmosphere. The nanoparticles and modified paint were characterized using SEM, TEM, XPS, and XRD techniques. The antimicrobial activity of the nanoparticles and modified paint layers was tested against P. aeruginosa, S. aureus, MRSA, E. coli bacteria, and C. albicans using ISO 22196. The antiviral activity against smallpox virus was tested according to ISO 21702. Flow cytometry tests were used to investigate the toxicity of the modified paint coating. As-synthesized nanoparticles had "Janus-like" morphology, with a clear interface inside the nanoparticle. Nanoparticles had enhanced antibacterial activity, which is based on the nanoparticle photocatalytic activity in water decomposition and reactive oxygen species generation. The paint coating with a ZnO-Ag nanoparticle mass ratio of 1.0 wt.% displayed significant antibacterial activity (more than a 99% reduction) and 100% antifungal activity. In addition, this coating inactivates >99% of the virus after 2 h of contact relative to a nontreated control paint. The paint coating showed low toxicity against the sensitive 3T3 fibroblast cell line. More than 90% cell viability was observed after 24 h of incubation with the sample extract. Therefore, heterophase ZnO-Ag nanoparticles have high biocidal activity and low toxicity use and can be applied to other commercial water-based paints to improve their performance against pathogens. [ABSTRACT FROM AUTHOR]

Abstract Background Antimicrobial materials or surfaces are advertised as part of infection prevention bundles. However, the efficacy of such antimicrobial surfaces has not been sufficiently investigated in hospitals. In this study, the antimicrobial activity of examination gloves with light-activated antimicrobial properties against Gram-positive microorganisms was investigated modelling real live conditions. Method In a standardized experimental set-up with dry and realistic contamination, the antimicrobial properties of gloves claiming light dependent antimicrobial activity against Gram-positive organisms were tested in comparison with conventional examination gloves. All gloves were contaminated through a standardized activity of the test persons for construction with contaminated building blocks. For contamination suspensions of Enterococcus faecium ATCC 6057, Acinetobacter baumannii (outbreak strain), methicillin resistant Staphylococcus aureus ATCC 43300 or E. faecium (VRE) patient isolate were dried on the surfaces. After the standardized activity, the gloves were held for 10 min in the light present in the room (bright conditions) and the grade of contamination was determined subsequently by quantitative culture. In one experimental series gloves were held in a dark box after contamination as a control (dark conditions). Results The light intensity in all experiments under bright conditions was significantly above the limit value specified by the manufacturer for the activation of antimicrobial properties (> 500 lx). The mean values for experiments with antimicrobial active and non-active gloves were 955 and 935 lx, respectively. As claimed by the manufacture, the gloves showed no sufficient efficacy against A. baumannii under bright conditions. Against Gram-positive microorganisms such as E. faecium, E. faecium (VRE) and methicillin resistant S. aureus the gloves showed only very low antimicrobial activity with a reduction factor 4 log10 within 5 min for Gram-positive microorganisms claimed for the product using a standard test procedure (ASTM D7907) could not be confirmed in a realistic experimental test set-up even after 10 min of light exposure. The effectiveness against Gram-positive microorganisms should be further investigated under realistic (dry) conditions, including patient care. At this stage, the use of supposedly antimicrobial gloves should not be recommended, as the belief in their efficacy may encourage the misuse of gloves.

Abstract Graphene is emerging in numerous wearable and biomedical applications. Understanding the impact of graphene‐based nanocomposites over bacterial activity is critical for design appropriate technical solutions. In this work, antibacterial activity of monolayer and few‐layer graphene is tested against Gram‐negative and Gram‐positive model bacteria. Such graphene‐based nanomaterials present different effects on bacteria viability, depending on concentration and shape. The presence of dopant agents can either increase or revert graphene antibacterial effect. Among other bactericidal mechanisms, we also demonstrate that graphene surface polarity is connected to antibacterial properties and can be easily modified by surface charge transfer doping. This electrophilicity tuning offers a novel mechanism for the molecular basis of graphene's antibacterial activity.

Titanium alloys are commonly used as biomaterials in musculoskeletal applications, but their long-term efficacy can be limited by wear and corrosion, stress shielding, and bacterial colonization. As a promising alternative, bulk metallic glasses (BMGs) offer superior strength and corrosion resistance, but the influence of their chemical composition on their bioactivity remains largely unexplored. This study, therefore, aims to examine how the surface chemistry of palladium (Pd)-, platinum (Pt)-, and titanium (Ti)-based BMGs can steer their response to biological systems. The chemical composition of BMGs governs their thermophysical and mechanical properties, with Pd-based BMGs showing exceptional glass-forming ability suitable for larger implants, and all BMGs exhibiting a significantly lower Young's modulus than Ti-6Al-4 V (Ti64), suggesting a potential to reduce stress shielding. Although BMGs feature copper depletion at the near surface, their surface chemistry remains more stable than that of Ti64 and supports blood biocompatibility. Fibrin network formation is heavily dependent on BMGs' chemical composition and Ti-based BMGs support thicker fibrin network formation than Ti64. Furthermore, BMGs outperform Ti64 in promoting mineralization of human bone progenitor cells and demonstrate antimicrobial properties against Staphylococcus aureus in a surface chemistry-dependent manner, thereby indicating their great potential as biomaterials for musculoskeletal applications. [ABSTRACT FROM AUTHOR]

Electrolyte jet machining (EJM) and electrodeposition present unexploited opportunities for the manufacturing of multiscale structured surfaces. The present work assesses the morphology and antibacterial properties of textured and multiscale stainless steel surfaces produced by EJM with a new 50 mm × 0.3 mm slit nozzle, as well as multiscale surfaces subject to electrodeposition with copper. Characterisation of the surface morphology obtained via EJM with various combinations of current density, machining time and groove spacing is performed to facilitate the selection of representative surfaces for bacterial retention tests. Higher current density with constant applied charge leads to lower surface roughness at constant scanning speed and greater groove depth and width under static conditions. Groove depth is proportional to machining time at constant current density, while a groove pitch of 1.05 mm is found to provide the optimum compromise between maximum groove depth and complete surface coverage. Microscale surface features are found to reduce Escherichia coli and Pseudomonas aeruginosa retention by up to 97% compared to untextured control surfaces, while larger grooves play a role in inhibiting bacterial attachment by inducing turbulence. The presence of copper agglomerates completely eliminates bacterial retention under the tested conditions. The developed process provides a flexible approach to tailoring surface properties for specific applications requiring antimicrobial properties. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial materials or surfaces are advertised as part of infection prevention bundles. However, the efficacy of such antimicrobial surfaces has not been sufficiently investigated in hospitals. In this study, the antimicrobial activity of examination gloves with light-activated antimicrobial properties against Gram-positive microorganisms was investigated modelling real live conditions. Method: In a standardized experimental set-up with dry and realistic contamination, the antimicrobial properties of gloves claiming light dependent antimicrobial activity against Gram-positive organisms were tested in comparison with conventional examination gloves. All gloves were contaminated through a standardized activity of the test persons for construction with contaminated building blocks. For contamination suspensions of Enterococcus faecium ATCC 6057, Acinetobacter baumannii (outbreak strain), methicillin resistant Staphylococcus aureus ATCC 43300 or E. faecium (VRE) patient isolate were dried on the surfaces. After the standardized activity, the gloves were held for 10 min in the light present in the room (bright conditions) and the grade of contamination was determined subsequently by quantitative culture. In one experimental series gloves were held in a dark box after contamination as a control (dark conditions). Results: The light intensity in all experiments under bright conditions was significantly above the limit value specified by the manufacturer for the activation of antimicrobial properties (> 500 lx). The mean values for experiments with antimicrobial active and non-active gloves were 955 and 935 lx, respectively. As claimed by the manufacture, the gloves showed no sufficient efficacy against A. baumannii under bright conditions. Against Gram-positive microorganisms such as E. faecium, E. faecium (VRE) and methicillin resistant S. aureus the gloves showed only very low antimicrobial activity with a reduction factor < 1 log10 even after 10 min in bright conditions. Interestingly, comparable results for experiments with A. baumannii and E. faecium were shown under dark conditions. Conclusion: The lack of activity of the active principle against Gram-negative microorganisms could be confirmed. The reduction factors of > 4 log10 within 5 min for Gram-positive microorganisms claimed for the product using a standard test procedure (ASTM D7907) could not be confirmed in a realistic experimental test set-up even after 10 min of light exposure. The effectiveness against Gram-positive microorganisms should be further investigated under realistic (dry) conditions, including patient care. At this stage, the use of supposedly antimicrobial gloves should not be recommended, as the belief in their efficacy may encourage the misuse of gloves. [ABSTRACT FROM AUTHOR]

Healthcare-associated infections are serious public health problem. Besides antibacterial, antifungal, and antiviral therapies, one potential strategy for breaking the chain of infection transmission is via the installation of antibacterial surfaces. Aluminum is an attractive material for fabricating frequently touched surfaces such as doorknobs, push plate, bedrails, etc. Recently, our research group and others have demonstrated that by utilizing appropriate surface treatment technologies, such as anodization, low-surface-energy passivation, and electrochemical surface modification, on an AA6061-T6 aluminum alloy, aluminum could be rendered antimicrobial. Such surface technologies can be efficient in antimicrobial activities, and they also show advantages in terms of robustness and durability. These novel surfaces have been shown to reduce the microbial burden of clinically relevant pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. [ABSTRACT FROM AUTHOR]

Coating medical implants with antibacterial polymers may prevent postoperative infections which are a common issue for conventional titanium implants and can even lead to implant failure. Easily applicable diblock copolymers are presented that form polymer brushes via "grafting to" mechanism on titanium and equip the modified material with antibacterial properties. The polymers carry quaternized pyridinium units to combat bacteria and phosphonic acid groups which allow the linear chains to be anchored to metal surfaces in a convenient coating process. The polymers are synthesized via reversible‐addition‐fragmentation‐chain‐transfer (RAFT) polymerization and postmodifications and are characterized using NMR spectroscopy and SEC. Low grafting densities are a major drawback of the "grafting to" approach compared to "grafting from". Thus, the number of phosphonic acid groups in the anchor block are varied to investigate and optimize the surface binding. Modified titanium surfaces are examined regarding their composition, wetting behavior, streaming potential, and coating stability. Evaluation of the antimicrobial properties revealed reduced bacterial adhesion and biofilm formation for certain polymers, albeit the cell biocompatibility against human gingival fibroblasts is also impaired. The presented findings show the potential of easy‐to‐apply polymer coatings and aid in designing next‐generation implant surface modifications. [ABSTRACT FROM AUTHOR]

Graphene is emerging in numerous wearable and biomedical applications. Understanding the impact of graphene‐based nanocomposites over bacterial activity is critical for design appropriate technical solutions. In this work, antibacterial activity of monolayer and few‐layer graphene is tested against Gram‐negative and Gram‐positive model bacteria. Such graphene‐based nanomaterials present different effects on bacteria viability, depending on concentration and shape. The presence of dopant agents can either increase or revert graphene antibacterial effect. Among other bactericidal mechanisms, we also demonstrate that graphene surface polarity is connected to antibacterial properties and can be easily modified by surface charge transfer doping. This electrophilicity tuning offers a novel mechanism for the molecular basis of graphene's antibacterial activity. [ABSTRACT FROM AUTHOR]

Nanomaterials, specifically nano-topographies, have been explored for their antimicrobial activity toward bacteria, fungi and even viruses. A decade ago, we discovered that the nanopillar topography of insect wings such as cicadas, dragonflies and damselflies, were not repelling bacteria as previously surmised, but bacteria were attaching and consequently being killed. The nature of the bactericidal effect associated with nanostructured insect wings has been extended to include antimicrobial activity toward both to environmental and pathogenic fungi. Specifically, the antimicrobial nature is associated with the physical disintegration of attached microbes due to a mechanical stress imposed on the cell membrane, which stretches and breaks. This exciting new discovery implies that, if successfully replicated on the surface of biomaterials and implantable devices, systemic or local administration of antibiotics are no longer required to kill bacteria that attach on such surfaces.

Various assay methods have been developed to study antimicrobial activity based on contamination of surfaces with different amounts of liquid bacterial suspensions. Since surfaces with frequent hand contact are typically touched in a dry state in clinical settings, these tests may be inappropriate at assessing effectiveness to reduce pathogen transmission. To investigate a surface previously confirmed to display antimicrobial activity even after drying of small volumes of bacterial suspension (Egger antimicrobial surfaces: EAS) under conditions modelling dry contamination using a touch-transfer method. EAS, an antimicrobial copper alloy, as well as a negative control were examined to assess interlaboratory test reproducibility. Significantly fewer bacteria on EAS after touch transfer and some differences in the touch transmission were detected between the two laboratories. However, an identical assessment of effectiveness for EAS came from both laboratories. Interestingly, despite previously detected antimicrobial efficacy of EAS and the antimicrobial copper alloy after liquid contamination, insufficient activity was observed under dry conditions during a contact time of 4 h by both laboratories. Experiments under standardized air humidity in one laboratory revealed at least for copper a strong influence of humidity on antimicrobial activity. These data indicate that procedures involving contamination of surfaces with organisms suspended in liquids are not directly comparable to dry contamination. Since, in the real world of a hospital, organisms are typically transferred between dry surfaces, further standardization of the touch-transfer method is worthwhile for a better understanding of the efficacy of such surfaces. [ABSTRACT FROM AUTHOR]

Abstract Coating medical implants with antibacterial polymers may prevent postoperative infections which are a common issue for conventional titanium implants and can even lead to implant failure. Easily applicable diblock copolymers are presented that form polymer brushes via “grafting to” mechanism on titanium and equip the modified material with antibacterial properties. The polymers carry quaternized pyridinium units to combat bacteria and phosphonic acid groups which allow the linear chains to be anchored to metal surfaces in a convenient coating process. The polymers are synthesized via reversible‐addition‐fragmentation‐chain‐transfer (RAFT) polymerization and postmodifications and are characterized using NMR spectroscopy and SEC. Low grafting densities are a major drawback of the “grafting to” approach compared to “grafting from”. Thus, the number of phosphonic acid groups in the anchor block are varied to investigate and optimize the surface binding. Modified titanium surfaces are examined regarding their composition, wetting behavior, streaming potential, and coating stability. Evaluation of the antimicrobial properties revealed reduced bacterial adhesion and biofilm formation for certain polymers, albeit the cell biocompatibility against human gingival fibroblasts is also impaired. The presented findings show the potential of easy‐to‐apply polymer coatings and aid in designing next‐generation implant surface modifications.

The COVID-19 pandemic has shown that infection prevention actions need to be more efficient in public indoor environments. In addition to SARS-CoV-2, the cause of COVID-19, many pathogens, including other infectious viruses, antibiotic-resistant bacteria, and premise plumbing pathogens, are an invisible threat, especially in public indoor spaces. The indoor hygiene concept for comprehensive infection prevention in built environments highlights that the indoor environment should be considered as a whole when aiming to create buildings with increased infection prevention capacity. Within indoor environments, infections can indirectly spread through surfaces, air, and water systems. Many methods, such as antimicrobial technologies and engineering solutions, targeting these indoor elements are available, which aim to increase the hygiene level in indoor environments. The architectural design itself lays a foundation for more efficient infection prevention in public buildings. Touchless solutions and antimicrobial coatings can be applied to frequently touched surfaces to prevent indirect contact infection. Special ventilation solutions and air purification systems should be considered to prevent airborne infection transmissions. Proper design and use of water supply systems combined with water treatment devices, if necessary, are important in controlling premise plumbing pathogens. This article gives a concise review of the functional and available hygiene-increasing methods—concentrating on indoor surfaces, indoor air, and water systems—to help the professionals, such as designers, engineers, and maintenance personnel, involved in the different stages of a building’s lifecycle, to increase the infection prevention capacity of public buildings.

[Display omitted] • Quaternized (Dimethylamino)ethyl methacrylate-based photopolymerizable monomer and crosslinker was prepared. • The impact of varying crosslinker percentages on 3D printing resolution was examined. • The physicochemical properties of fully quaternized polymers can be tailored by adjusting the monomer-to-crosslinker ratio. • The fully quaternized polymers exhibited excellent antimicrobial activity without significant cytotoxicity. Nowadays, medical devices or implants are widely used in the medical field to treat different diseases. However, bacterial infections are one of the significant problems associated with medical devices and are recognized as a concern in healthcare worldwide. Addressing this problem has driven the exploration of new materials with potent antibacterial properties. In this regard, quaternary ammonium compounds (QACs), which are organic salts with an alkane chain and a charged part of quaternary ammonium groups, came up with a potent antibacterial activity. Herein, we report for the first-time dimethylamino ethyl methacrylate (DMAEM) derived quaternary ammonium monomer and crosslinker to prepare photoresins for DLP (Digital light processing) 3D printing. The structure of the synthesized monomer and crosslinker was confirmed via FTIR (Fourrier Transform Infrared) and 1H NMR (Hydrogen Nuclear Magnetic Resonance) while the physicochemical properties of the 3D printed polymer were investigated using TGA (Thermogravimetric Analysis), DSC (Differential Scanning Calorimeter) and UTM (Universal testing machine). By optimizing the printing conditions and monomer to crosslinker ratio, we can print high-resolution 3D-printed objects. Additionally, in vitro biodegradation, cytocompatibility, and hemocompatibility tests revealed that the printed polymers are biodegradable, cytocompatible, and hemocompatible in nature. More importantly, the printed polymers exhibited strong antibacterial activity against both gram-negative and gram-positive bacteria, suggesting their potential utility in personalized antibacterial medical devices. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial-resistant bacterial strains has led to novel approaches for combating bacterial infections and surface contamination. More specifically, efforts in combining nanotechnology and biomimetics have led to the development of next-generation antimicrobial/antifouling nanomaterials. While nature-inspired nanoscale topographies are known for minimizing bacterial attachment through surface energy and physicochemical features, few studies have investigated the combined inhibitory effects of such features in combination with chemical alterations of these surfaces. Studies describing surface alterations, such as quaternary ammonium compounds (QACs), have also gained attention due to their broad spectrum of inhibitory activity against bacterial cells. Similarly, antimicrobial peptides (AMPs) have exhibited their capacity to reduce bacterial viability. To maximize the functionality of modified surfaces, the integration of patterned surfaces and functionalized exteriors, achieved through physical and chemical surface alterations, have recently been explored as viable alternatives. Nonetheless, these modifications are prone to challenges that can reduce their efficacy considerably in the long term. Their effectiveness against a wider array of microbial cells is still a subject of investigation. This review article will explore and discuss the emerging trends in biomimetics and other antimicrobials while raising possible concerns about their limitations and discussing future implications regarding their potential combined applications.

Healthcare-associated infections are serious public health problem. Besides antibacterial, antifungal, and antiviral therapies, one potential strategy for breaking the chain of infection transmission is via the installation of antibacterial surfaces. Aluminum is an attractive material for fabricating frequently touched surfaces such as doorknobs, push plate, bedrails, etc. Recently, our research group and others have demonstrated that by utilizing appropriate surface treatment technologies, such as anodization, low-surface-energy passivation, and electrochemical surface modification, on an AA6061-T6 aluminum alloy, aluminum could be rendered antimicrobial. Such surface technologies can be efficient in antimicrobial activities, and they also show advantages in terms of robustness and durability. These novel surfaces have been shown to reduce the microbial burden of clinically relevant pathogens such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.

Implants and various medical devices possess surfaces that are prone to bacterial colonization due to bacterial adhesion and the formation of biofilms. Therefore, inhibiting bacterial colonization is a crucial strategy for preventing infections. Although there have been reports on antibacterial surfaces, the synthetic processes involved are often complex and labor-intensive, which significantly limits their practical applications. Furthermore, there is a lack of studies investigating the interplay between antibacterial performance and stability. In this study, silver ions were reduced to form silver nanoparticles, which were then loaded onto polydopamine (PDA) particles. The successful assembly of PDA-Ag on the surface of the titanium alloy was confirmed through X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDS). The morphologies of the micro- and nanoparticles, as well as the surface morphology after deposition, were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and a 3D optical profilometer. The abrasion experiments conducted on the three surfaces demonstrated that the TC4@PDA–Ag3 surface exhibited superior friction performance compared to the other two surfaces. Antibacterial and antibacterial stability experiments were conducted on this series of surfaces. The results indicated that the adhesion rate of TC4@PDA–Ag3 on Escherichia coli (E. coli) was 99.68 %, while the antibacterial efficiency against Staphylococcus aureus (S. aureus) was 95.97 %. This study presents a novel approach to address the issue of implant surface infections by demonstrating resistance to bacterial adhesion and colonization, specifically against E. coli and S. aureus. • The PDA-Ag submicron composites and three TC4@PDA-Ag series surfaces were prepared using a simple method. • The TC4@PDA-Ag series of surfaces has been demonstrated to be effective in the eradication of E. coli and S. aureus. • The TC4@PDA–Ag series surfaces have been demonstrated to possess anti-biofilm properties. • The TC4@PDA–Ag3 exhibits stability and long-term antimicrobial stability. [ABSTRACT FROM AUTHOR]

Increasing the use of hygienic high-touch surfaces with antimicrobial properties in health care and public spaces is one way to hinder the spread of bacteria and infections. This study investigates the antimicrobial efficacy and surface reactivity of commercial laminate and powder coated surfaces treated with silver-doped phosphate glass as antimicrobial additive towards two model bacterial strains, Escherichia coli and Bacillus subtilis, in relation to surface weathering and repeated cleaning. High-touch conditions in indoor environments were simulated by different extents of pre-weathering (repeated daily cycles in relative humidity at constant temperature) and simplified fingerprint contact by depositing small droplets of artificial sweat. The results elucidate that the antimicrobial efficacy was highly bacteria dependent (Gram-positive or Gram-negative), not hampered by differences in surface weathering but influenced by the amount of silver-doped additive. No detectable amounts of silver were observed at the top surfaces, though silver was released into artificial sweat in concentrations a thousand times lower than regulatory threshold values stipulated for materials and polymers in food contact. Surface cleaning with an oxidizing chemical agent was more efficient in killing bacteria compared with an agent composed of biologically degradable constituents. Cleaning with the oxidizing agent resulted further in increased wettability and presence of residues on the surfaces, effects that were beneficial from an antimicrobial efficacy perspective. [ABSTRACT FROM AUTHOR]

In dentistry, bone regeneration requires osteoinductive biomaterial with antibacterial properties. Polycaprolactone (PCL) may be combined with different nanofillers including reduced graphene oxide (rGO). Here, the amount of rGO filler was defined to obtain a biocompatible and antibacterial PCL-based surface supporting the adhesion and differentiation of human mesenchymal stem cells (MSCs). Compounds carrying three different percentages of rGO were tested. Among all, the 5% rGO-PCL compound is the most bacteriostatic against Gram-positive bacteria. All scaffolds are biocompatible. MSCs adhere and proliferate on all scaffolds; however, 5% rGO-PCL surface supports the growth of cells and implements the expression of extracellular matrix components necessary to anchor the cells to the surface itself. Moreover, the 5% rGO-PCL surface has superior osteoinductive properties confirmed by the improved alkaline phosphatase activity, mineral matrix deposition, and osteogenic markers expression. These results suggest that 5% rGO-PCL has useful properties for bone tissue engineering purposes. [ABSTRACT FROM AUTHOR]

Background: medical device-induced infections affect millions of lives worldwide and innovative preventive strategies are urgently required. Antimicrobial peptides (AMPs) appear as ideal candidates to efficiently functionalize medical devices surfaces and prevent bacterial infections. In this scenario, here, we produced antimicrobial polydimethylsiloxane (PDMS) by loading this polymer with an antimicrobial peptide identified in human apolipoprotein B, r(P)ApoBLPro. Methods: once obtained loaded PDMS, its structure, anti-infective properties, ability to release the peptide, stability, and biocompatibility were evaluated by FTIR spectroscopy, water contact angle measurements, broth microdilution method, time-killing kinetic assays, quartz crystal microbalance analyses, MTT assays, and scanning electron microscopy analyses. Results: PDMS was loaded with r(P)ApoBLPro peptide which was found to be present not only in the bulk matrix of the polymer but also on its surface. ApoB-derived peptide was found to retain its antimicrobial properties once loaded into PDMS and the antimicrobial material was found to be stable upon storage at 4 °C for a prolonged time interval. A gradual and significant release (70% of the total amount) of the peptide from PDMS was also demonstrated upon 400 min incubation and the antimicrobial material was found to be endowed with anti-adhesive properties and with the ability to prevent biofilm attachment. Furthermore, PDMS loaded with r(P)ApoBLPro peptide was found not to affect the viability of eukaryotic cells. Conclusions: an easy procedure to functionalize PDMS with r(P)ApoBLPro peptide has been here developed and the obtained functionalized material has been found to be stable, antimicrobial, and biocompatible. [ABSTRACT FROM AUTHOR]

There is an increasing focus in healthcare environments on combatting antimicrobial resistant infections. While bacterial infections are well reported, infections caused by fungi receive less attention, yet have a broad impact on society and can be deadly. Fungi are eukaryotes with considerable shared biology with humans, therefore limited technologies exist to combat fungal infections and hospital infrastructure is rarely designed for reducing microbial load. In this study, a novel antimicrobial surface (AMS) that is modified with the broad‐spectrum biocide chlorhexidine is reported. The surfaces are shown to kill the opportunistic fungal pathogens Candida albicans and Cryptococcus neoformans very rapidly (<15 min) and are significantly more effective than current technologies available on the commercial market, such as silver and copper. [ABSTRACT FROM AUTHOR]

Novel composite self-disinfecting films of polylactic acid (PLA) filled with nanosized particles of double sodium–copper(II) paratungstate B Na2Cu3(CuOH)2[W12O40(OH)2]·32H2O (POM) were developed. The solvent casting (POM/PLA film) and solvent-free melt extrusion methods (Extr. POM/PLA film) were applied for film preparation. The copper (II) ion release to water from both types of the films after 10 days at different temperatures demonstrated that the PLA matrix acts as a diffusion barrier, and the resulting concentration of released copper in water at room temperature remained low, at 0.79% for POM/PLA film and 0.51% for Extr. POM/PLA film. The POM-containing films reveals a significant inhibitory effect against E. coli ATCC 25922 in the agar diffusion test. The numbers of CFUs in washes of the films after incubation for 24 h were found to be 3.6 log CFU mL–1 (POM/PLA film) and 4.1 log CFU mL–1 (Extr. POM/PLA film). The films combine the antibacterial properties of POM and a bio-based polymer matrix, which makes them a prospective coating material for applications in hospital indoor environments. Excellent thermal stability of POM gives a technological advantage for industrial manufacturing to allow the processing of novel composite material in the solvent free (molten) state. [ABSTRACT FROM AUTHOR]

Abstract In this literature review, the antipathogenic properties and contact-mediated antibacterial and antiviral performance of copper cold spray surfaces are assessed and compared with alternative antimicrobial materials that are able to kill and/or inactivate infectious agents via direct contact. Discussion is also provided concerning the suitability of copper cold spray material consolidations as biocidal and viricidal surfaces that retain long-term functionality as a preventative measure against fomite transmission of pathogenic agents and hospital-acquired infections from contaminated high-touch surfaces. Numerable alternative antimicrobial coatings and surfaces that do not rely upon the oligodynamic action of copper are detailed. Given the ongoing need for recognition of said alternative antimicrobial materials by authoritative agencies, such as the U.S. Environmental Protection Agency, the relevant literature on non-copper-based antipathogenic coatings and surfaces are then described. Furthermore, a wide-ranging take on antipathogenic copper cold spray coatings are provided and consideration is given to the distinctive grain-boundary mediated copper ion diffusion pathways found in optimizable, highly deformed, copper cold spray material consolidations that enable pathogen inactivation on surfaces from direct contact. To conclude this literature review, analysis of how copper cold spray coatings can be employed as a preventative measure against COVID-19 was also presented in light of on-going debates surrounding SARS-CoV-2’s non-primary, but non-negligible, secondary transmission pathway, and also presented in conjunction with the inevitability that future pathogens, which will be responsible for forthcoming global pandemics, may spread even more readily via fomite pathways too.

Microbial infection and antibiotic resistance is recognized as a serious problem to society from both an economical perspective and a health concern. To tackle this problem, “nanotechnology,” a multidisciplinary field of research, has provided a plethora of nanomaterials for potential applications in the antimicrobial sector. This letter discusses how antimicrobial nanomaterials are shaping this challenging field and being evaluated as therapeutic and medication delivery agents. The recently designed smart antimicrobial surfaces with switchable features that displayed synergistic antibacterial action were also highlighted. To end, we provide the current scenario and future perspectives with regards to emerging antimicrobial nano-engineered materials and nanotechnology.

Abstract There is an increasing focus in healthcare environments on combatting antimicrobial resistant infections. While bacterial infections are well reported, infections caused by fungi receive less attention, yet have a broad impact on society and can be deadly. Fungi are eukaryotes with considerable shared biology with humans, therefore limited technologies exist to combat fungal infections and hospital infrastructure is rarely designed for reducing microbial load. In this study, a novel antimicrobial surface (AMS) that is modified with the broad‐spectrum biocide chlorhexidine is reported. The surfaces are shown to kill the opportunistic fungal pathogens Candida albicans and Cryptococcus neoformans very rapidly (

Validation of the antimicrobial performance of contact-killing polymer surfaces through the experimental determination of bacterial adhesion or viability, is essential for their targeted development and application. However, there is not yet a consensus on the single most appropriate evaluation method or procedure. Combining and benchmarking previously reported assays could reduce the significant variation and misinterpretation of efficacy data obtained from different methods. In this work, we systematically investigated the response of bacterial cells to antiadhesive and antiseptic polymer coatings by combining (i) bulk solution-based, (ii) thin-film spacer-based, and (iii) direct-contact assays. In addition, we evaluated the studied assays using a five-point scoring framework that highlights key areas for improvement. Our data suggest that combined microscopy assays provide a more comprehensive representation of antimicrobial performance, thereby helping to identify effective types of antibacterial polymer coatings. [ABSTRACT FROM AUTHOR]

To help assess whether a potentially antimicrobial material, surface, or coating provides antimicrobial efficacy, a number of standardised test methods have been developed internationally. Ideally, these methods should generate data that supports the materials efficacy when deployed in the intended end-use application. These methods can be categorised based on their methodological approach such as suspension tests, agar plate/zone diffusion tests, surface inoculation tests, surface growth tests or surface adhesion tests. To support those interested in antimicrobial coating efficacy, this review brings together an exhaustive list of methods (for porous and non-porous materials), exploring the methodological and environmental parameters used to quantify antibacterial, antifungal, or antiviral activity. This analysis demonstrates that antimicrobial efficacy methods that test either fungi or viruses are generally lacking, whilst methods that test bacteria, fungi and viruses are not designed to simulate end-use/lack realistic conditions. As such, a number of applications for antimicrobial activity across medical touch screens, medical textiles and gloves and transport seat textiles are explored as example applications, providing guidance on modifications to existing methods that may better simulate the intended end-use of antimicrobial materials., Competing Interests: At the time of publication, J.R. is Deputy Editor in Chief of Access Microbiology., (Copyright © 2024 The Authors.)

An overview of the current surface treatments/coatings that introduce antimicrobial properties to the exposed surfaces in confined space stations is provided. General aspects, such as biofilm formation and the specific requirements associated with this application, are discussed. Antimicrobial coatings used on the International Space Station (ISS) are reviewed. A selection of commercial and developed coatings targeting space applications is presented. Also, some developments that can be used in the space industry are highlighted. [ABSTRACT FROM AUTHOR]

Featured Application: Recombinant protein polymers, genetically engineered to incorporate antimicrobial peptides, demonstrate a therapeutic effect. These materials can be employed for the development of antimicrobial and biocompatible surfaces/coatings produced by sustainable means. Antibacterial resistance is a major worldwide threat due to the increasing number of infections caused by antibiotic-resistant bacteria with medical devices being a major source of these infections. This suggests the need for new antimicrobial biomaterial designs able to withstand the increasing pressure of antimicrobial resistance. Recombinant protein polymers (rPPs) are an emerging class of nature-inspired biopolymers with unique chemical, physical and biological properties. These polymers can be functionalized with antimicrobial molecules utilizing recombinant DNA technology and then produced in microbial cell factories. In this work, we report the functionalization of rPBPs based on elastin and silk-elastin with different antimicrobial peptides (AMPs). These polymers were produced in Escherichia coli, successfully purified by employing non-chromatographic processes, and used for the production of free-standing films. The antimicrobial activity of the materials was evaluated against Gram-positive and Gram-negative bacteria, and results showed that the polymers demonstrated antimicrobial activity, pointing out the potential of these biopolymers for the development of new advanced antimicrobial materials. [ABSTRACT FROM AUTHOR]

Novel composite self-disinfecting films of polylactic acid (PLA) filled with nanosized particles of double sodium–copper(II) paratungstate B Na2Cu3(CuOH)2[W12O40(OH)2]·32H2O (POM) were developed. The solvent casting (POM/PLA film) and solvent-free melt extrusion methods (Extr. POM/PLA film) were applied for film preparation. The copper (II) ion release to water from both types of the films after 10 days at different temperatures demonstrated that the PLA matrix acts as a diffusion barrier, and the resulting concentration of released copper in water at room temperature remained low, at 0.79% for POM/PLA film and 0.51% for Extr. POM/PLA film. The POM-containing films reveals a significant inhibitory effect against E. coli ATCC 25922 in the agar diffusion test. The numbers of CFUs in washes of the films after incubation for 24 h were found to be 3.6 log CFU mL–1 (POM/PLA film) and 4.1 log CFU mL–1 (Extr. POM/PLA film). The films combine the antibacterial properties of POM and a bio-based polymer matrix, which makes them a prospective coating material for applications in hospital indoor environments. Excellent thermal stability of POM gives a technological advantage for industrial manufacturing to allow the processing of novel composite material in the solvent free (molten) state.

In this literature review, the antipathogenic properties and contact-mediated antibacterial and antiviral performance of copper cold spray surfaces are assessed and compared with alternative antimicrobial materials that are able to kill and/or inactivate infectious agents via direct contact. Discussion is also provided concerning the suitability of copper cold spray material consolidations as biocidal and viricidal surfaces that retain long-term functionality as a preventative measure against fomite transmission of pathogenic agents and hospital-acquired infections from contaminated high-touch surfaces. Numerable alternative antimicrobial coatings and surfaces that do not rely upon the oligodynamic action of copper are detailed. Given the ongoing need for recognition of said alternative antimicrobial materials by authoritative agencies, such as the U.S. Environmental Protection Agency, the relevant literature on non-copper-based antipathogenic coatings and surfaces are then described. Furthermore, a wide-ranging take on antipathogenic copper cold spray coatings are provided and consideration is given to the distinctive grain-boundary mediated copper ion diffusion pathways found in optimizable, highly deformed, copper cold spray material consolidations that enable pathogen inactivation on surfaces from direct contact. To conclude this literature review, analysis of how copper cold spray coatings can be employed as a preventative measure against COVID-19 was also presented in light of on-going debates surrounding SARS-CoV-2's non-primary, but non-negligible, secondary transmission pathway, and also presented in conjunction with the inevitability that future pathogens, which will be responsible for forthcoming global pandemics, may spread even more readily via fomite pathways too. [ABSTRACT FROM AUTHOR]

Surface protection against biofilms is still an open challenge. Current strategies rely on coatings that are meant to guarantee antiadhesive or antimicrobial effects. While it seems difficult to ensure antiadhesion in complex media and against all the adhesive arsenal of microbes, strategies based on antimicrobials lack from sustainable functionalization methodologies to allow the perfect efficiency of the grafted molecules. Here we used the high affinity ligand-receptor interaction between biotin and streptavidin to functionalize surfaces with lysozyme, an enzyme that degrades the bacterial peptidoglycan cell wall. Biotinylated lysozyme was grafted on surfaces coated with streptavidin receptors. Using atomic force microscopy (AFM)-based single molecule force spectroscopy, we showed that grafting through ligand-receptor interaction allows the correct orientation of the enzyme on the substrate for enhanced activity towards the microbial target. The antibacterial efficiency was tested against Micrococcus luteus and revealed that surface protection was improved when lysozyme was grafted through the ligand-receptor interaction. These results suggest that bio-molecular interactions are promising for a sustainable grafting of antimicrobial agents on surfaces. [ABSTRACT FROM AUTHOR]

Antimicrobial surfaces limit the spread of infectious diseases. To date, there is no antimicrobial coating that has widespread use because of short-lived and limited spectrum efficacy, poor resistance to organic material, and/or cost. Here, we present a paint based on waterborne latex particles that is supramolecularly associated with quaternary ammonium compounds (QACs). The optimal supramolecular pairing was first determined by immobilizing selected ions on self-assembled monolayers exposing different groups. The QAC surface loading density was then increased by using polymer brushes. These concepts were adopted to develop inexpensive paints to be applied on many different surfaces. The paint could be employed for healthcare and food production applications. Its slow release of QAC allows for long-lasting antimicrobial action, even in the presence of organic material. Its efficacy lasts for more than 90 washes, and importantly, once lost, it can readily be restored by spraying an aqueous solution of the QAC. We mainly tested cetyltrimethylammonium as QAC as it is already used in consumer care products. Our antimicrobial paint is broad spectrum as it showed excellent antimicrobial efficiency against four bacteria and four viruses.