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Due to the increasing occurrence of antibiotic-resistant bacterial strains worldwide, there is an urgent need for developing antibiotic-independent strategies to combat bacterial infections. In this study, we developed a modular approach for trapping, retaining, and killing bacteria by means of porous, poly-(lactic-co-glycolic acid) (PLGA)-based microcapsules with integrated gold nanorods (AuNRs). AuNRs were coated with thiol-functionalized PLGA beforehand to ensure efficient integration into the hydrophobic microcapsule shells. For the efficient generation of AuNR-functionalized microcapsules, we designed and developed a fast and reliable one-pot bulk emulsification production method. When exposing the AuNR-decorated microcapsules to near-infrared light, both motile and nonmotile bacteria were killed in a highly localized manner due to AuNR-generated heat. Importantly, fibroblast cell viability tests performed with AuNR-decorated microcapsules revealed good biocompatibility of the system. Such a modular antibacterial system can be employed in various applications, including, but not limited to, implant coatings, flushing solutions, and sewage treatment. [ABSTRACT FROM AUTHOR]

Bacterial infection remains a major complication answering for the failures of various implantable medical devices. Tremendous extraordinary advances have been published in the design and synthesis of antimicrobial materials addressing this issue; however, the clinical translation has largely been blocked due to the challenge of balancing the efficacy and safety of these materials. Here, calcium's biochemical features, natural roles in pathogens and the immune systems, and advanced uses in infection medications are illuminated, showing calcium is a promising target for developing implantable devices with less infection tendency. The paper gives a historical overview of biomedical uses of calcium and summarizes calcium's merits in coordination, hydration, ionization, and stereochemistry for acting as a structural former or trigger in biological systems. It focuses on the involvement of calcium in pathogens' integrity, motility, and metabolism maintenance, outlining the potential antimicrobial targets for calcium. It addresses calcium's uses in the immune systems that the authors can learn from for antimicrobial synthesis. Additionally, the advances in calcium's uses in infection medications are highlighted to sketch the future directions for developing implantable antimicrobial materials. In conclusion, calcium is at the nexus of antimicrobial defense, and future works on taking advantage of calcium in antimicrobial developments are promising in clinical translation. [ABSTRACT FROM AUTHOR]

Antibacterial materials with high hydrophobicity have drawbacks such as protein adsorption, bacterial contamination, and biofilm formation, which are responsible for some serious adverse health events. Therefore, antibacterial materials with high hydrophilicity are highly desired. In this paper, UV‐curable antibacterial materials are prepared from silicone−containing Choline chloride (ChCl) functionalized hyperbranched quaternary ammonium salts (QAS) and tri−hydroxylethyl acrylate phosphate (TAEP). The materials show high hydrophilic performance because their water contact angle is as low as 19.3°. The materials also exhibit quite high antibacterial efficiency against S. aureus over 95.6%, fairly high transmittance over 90%, and good mechanical performance with tensile strength as high as 6.5 MPa. It reveals that it is a feasible strategy to develop antibacterial materials with low hydrophobicity from silicone‐modified ChCl‐functionalized hyperbranched QAS. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were in‐situ synthesized in silk sericin/poly(vinyl alcohol) (SS/PVA) mixtures by an easy one‐step synthesis method with the presence of ultraviolet (UV) radiation. Then, the SS/PVA composite membranes containing AgNPs were obtained by solvent casting method. The chemical structures of the membranes were investigated by fourier‐transform infrared spectroscopy (FTIR) and results showed that the membranes were a mixture of silk sericin and PVA. The morphological features of the membranes were investigated by field emission scanning electron microscopy (FE‐SEM) and it was seen that AgNPs containing membranes have heterogeneous structures. Energy dispersive spectroscopy (EDS) analysis revealed that the membranes contain carbon, oxygen, nitrogen, sulfur and silver. X‐ray diffractometer (XRD) and thermogravimetric (TGA) analyses also proved the presence of AgNPs in the structure of membranes. The antibacterial activities of membranes containing AgNPs were investigated on Staphylococcus aureus and Escherichia coli bacteria with disk diffusion test and liquid culture medium incubation. It was found that SS/PVA membranes containing 5 and 10 mM AgNPs have quite high antibacterial activity on both types of bacteria. The functional SS/PVA membranes have capacity to be used in biomedical applications such as wound care materials. [ABSTRACT FROM AUTHOR]

Polymer hydrogels find extensive application in biomedicine, serving specific purposes such as drug delivery, biosensing, bioimaging, cancer therapy, tissue engineering, and others. In response to the growing threat of bacterial infections and the escalating resistance to conventional antibiotics, this research introduces a novel injectable, self‐healing antimicrobial hydrogel comprising bioactive aldolized hyaluronic acid (AHA) and quaternized chitosan (QCS). This designed QCS/AHA hydrogel incorporates self‐assembling peptide nanofibers (PNFs) and small‐sized silver nanoparticles (AgNPs) for tailored functionality. The resulting hybrid QCS/AHA/PNF/AgNPs hydrogel demonstrates impressive rheological characteristics, broad‐spectrum antimicrobial efficacy, and high biocompatibility. Notably, its antimicrobial effectiveness against Escherichia coli and S. aureus surpasses 99.9%, underscoring its potential for treating infectious wounds. Moreover, the rheological analysis confirms its excellent shear‐thinning and self‐healing properties, enabling it to conform closely to irregular wound surfaces. Furthermore, the cytotoxicity assessment reveals its compatibility with human umbilical vein endothelial cells, exhibiting no significant adverse effects. The combined attributes of this bioactive QCS/AHA/PNF/AgNPs hydrogel position it as a promising candidate for antimicrobial applications and wound healing. [ABSTRACT FROM AUTHOR]

Biomaterials capable of continuously inactivating pathogens are essential for suppressing transmission of infectious diseases, such as epidemic cerebrospinal meningitis and pulmonary tuberculosis. Here, capillary condensation of air moisture within nano‐confined spaces between superhydrophilic rigid nanorods is shown and target microbiology spontaneously stretch and inactivate aerosolized microorganisms. Specifically, the negative Gaussian curvature‐shaped water condensate causes fluidic straining, comprising surface tension and Laplace pressure, strong enough to deform and eliminate the selected bacteria. Plate counting quantifies the sharply reduced contact‐killing period for superhydrophilic and bare nanorods (6 vs 100 min for E. coli, 20 vs 120 min for S. aureus) under relative humidity of 70%. Theoretical calculations and experimental studies indicate increased mechanical straining and mechano‐bactericidal by improving air moisture content. To further illustrate utility, long‐term antibacterial medical masks are fabricated by integrating such nanorods onto commercial fabrics. Collectively, these findings highlight the immense potential of capillary condensation‐induced fluidic straining as an eco‐friendly, broad‐spectrum, and highly efficient antibacterial strategy. [ABSTRACT FROM AUTHOR]

In recent years, interest in metal-based antibacterial materials has increased due to microorganisms gaining resistance to antibiotics. Silk sericin obtained from Bombyx mori cocoon has found use in many different areas thanks to its biocompatibility, hydrophilic character and biodegradability. Zinc oxide nanoparticles (ZnONPs) obtained in various zinc salts exhibit broad-spectrum antibacterial properties. In this study, to be produce metal based antibacterial materials, synthesis of silk sericin-coated ZnONPs (SS-ZnONPs) in a green and scalable method was investigated by using silk sericin protein as both reducing and capping agent to obtain ZnONPs. For producing SS-ZnONPs, 2% silk sericin solution was mixed with Zn(NO3)2 solution and the blend solution was heated at 100 °C for a certain period of time. Observing surface plasmon resonance (SPR) peak specific at 380 nm in the UV-vis spectrum of SS-ZnONPs represented the formation of ZnONPs. Then, the chemical, morphological, crystalline, thermal, and antibacterial properties of the synthesized SS-ZnONPs were examined. Characteristic peak of the Zn-O band was found in fourier transform infrared spectroscopy (FTIR) analysis of SSZnONPs. According to scanning electron microscopy (SEM) analyses, ZnONPs had morphology similar to cubic/hexagonal shape, showed a uniform structure, and did not represent any agglomerations. In energy dispersive spectroscopy (EDS) analyses of SS-ZnONPs, peaks belonging to carbon, nitrogen, oxygen, sulphur, and zinc elements were observed. The formation of Zn peak indicated that the zinc ions were transformed into ZnONPs. In addition, characteristic peaks of zinc were seen in the X-ray diffractometer (XRD) result of SS-ZnONPs. Thermogravimetric analysis (TGA) showed that the thermal stability and remaining amount of SS-ZnONPs was higher compared to pure silk sericin powder due to the formation of ZnONPs. Lastly, agar well diffusion test was carried out with Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) bacteria and SS-ZnONPs showed antibacterial action against S. aureus. It has been observed that the obtained SS-ZnONPs can be used as antibacterial agents. However, it was also understood that the ZnONPs concentration in this study was low for high antibacterial activity. [ABSTRACT FROM AUTHOR]

Abstract Bacterial infection remains a major complication answering for the failures of various implantable medical devices. Tremendous extraordinary advances have been published in the design and synthesis of antimicrobial materials addressing this issue; however, the clinical translation has largely been blocked due to the challenge of balancing the efficacy and safety of these materials. Here, calcium's biochemical features, natural roles in pathogens and the immune systems, and advanced uses in infection medications are illuminated, showing calcium is a promising target for developing implantable devices with less infection tendency. The paper gives a historical overview of biomedical uses of calcium and summarizes calcium's merits in coordination, hydration, ionization, and stereochemistry for acting as a structural former or trigger in biological systems. It focuses on the involvement of calcium in pathogens’ integrity, motility, and metabolism maintenance, outlining the potential antimicrobial targets for calcium. It addresses calcium's uses in the immune systems that the authors can learn from for antimicrobial synthesis. Additionally, the advances in calcium's uses in infection medications are highlighted to sketch the future directions for developing implantable antimicrobial materials. In conclusion, calcium is at the nexus of antimicrobial defense, and future works on taking advantage of calcium in antimicrobial developments are promising in clinical translation.

The rise of antibiotic-resistant infectious diseases caused by various bacterial pathogens has emerged as a major global health concern. As a result, there has been a growing effort to develop innovative antimicrobial materials as an alternative solution to combat multidrug-resistant (MDR) bacteria. Among these materials, metal nanoparticles (MNPs), particularly multi-metallic nanoparticles (MMNPs), have been found to demonstrate promising potential in fighting against antimicrobial resistance. The unique physiochemical properties and excellent biocompatibility of MMNPs contribute to their remarkable antimicrobial activity. MMNPs, composed of multiple metals, exhibit diverse electronic, optical, and magnetic properties. These multifunctional characteristics, including size, shape, surface area to volume ratio, and surface charge potential, facilitate favorable interactions with bacterial cell membranes. Consequently, MMNPs can disrupt the bacteria cell membrane, metal ion release, biomolecule damage, induce the generation of reactive oxygen species (ROS), cause protein dysfunction, and inflict DNA damage within the bacterial host's environment. This scientific review aims to provide a comprehensive summary and comparison of research progress concerning the antibacterial activities of multi-metallic nanoparticles, as well as their synergistic effects. Additionally, the scientific review elucidates the mechanisms through which MMNPs exert their antibacterial effects. Significant emphasis has been placed on recent promising advances of MMNPs that aid in overcoming antibacterial resistance. The physiochemical and multifunctional properties of MMNPs play a pivotal role in determining their effectiveness against bacterial infections. By integrating current knowledge on the antibacterial activities of MMNPs, this scientific review offers valuable insights into the potential applications of MMNPs in combating bacterial infections. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the biocompatibility, osteogenic and antibacterial activity of biomedical devices based on Magnesium (Mg) Alloys manufactured by Superplastic Forming process (SPF) and subjected to Hydrothermal (HT) and Sol-Gel Treatment (Sol-Gel). Mg-SPF devices subjected to Hydrothermal (Mg-SPF+HT) and Sol-Gel Treatment (Mg-SPF+Sol-Gel) were investigated. The biocompatibility of Mg-SPF+Sol-Gel and Mg-SPF+HT devices was observed by indirect and direct cytotoxicity assays, whereas the colonization of sample surfaces was assessed by confocal microscopy. qRT-PCR analysis and microbial growth curve analyses were employed to evaluate the osteogenic and antibacterial activity of both SPF-Mg treated devices, respectively. Mg-SPF+HT and Mg-SPF+Sol-Gel showed a high degree of biocompatibility. Analysis of mRNA expression of osteogenic genes in cells cultured on Mg-treated devices revealed a significant upregulation of the expression levels of BMP2 and Runx-2. Furthermore, the bacterial growth in strains developed in contact with both the Mg-SPF+HT and Mg-SPF+Sol-Gel devices was lower than that observed in the control. Hydrothermal and Sol-Gel Treatments of Mg alloys obtained through the SPF process demonstrated bioactive, osteogenic and antibacterial activity, offering a promising alternative to conventional Mg-based devices. The obtained Mg-based materials may have the potential to enhance the tunability of temporary devices in maxillary reconstruction, eliminating the need for second surgeries, and ensuring a good bone reconstruction and a reduced implant failure rate due to bacterial infections. ● Surface-functionalized Mg-based materials may promote osteogenesis. ● HT and Sol-Gel treatment both improved osteogenic/osteoinductive properties. ● Mg-based devices exhibited antibacterial properties. ● Mg-based materials seemed to be promising in treating refractory bone diseases. [ABSTRACT FROM AUTHOR]

Bacterial infections and their drug resistance are one of the enormous health challenges in the world today, causing huge casualties and economic losses worldwide every year. Hydrogel is a three-dimensional polymer network structure colloid with good hydrophilicity, unique three-dimensional network, good biocompatibility and cell adhesion. Therefore, hydrogel is a new type of biomaterial suitable for the antibacterial application and is expected to become a potential antibacterial material to solve antibiotic resistance. According to the corresponding antibacterial methods, the antibacterial technologies in hydrogels can be roughly classified into the following categories: (i) hydrogels loaded with antibacterial substances; (ii) hydrogels with inherent antibacterial activity; (iii) antibacterial hydrogels using photoresponsive therapy. This article will briefly introduce the basic principles, methods and applications of various hydrogel antibacterial technologies, and preliminarily discuss the difficulties and challenges in the future. [ABSTRACT FROM AUTHOR]

The aim of the present work is to use the latest achievements of nanotechnology (atomic layer deposition, ALD) in the field of food packaging to prevent biofilm formation by food-associated bacteria. Some potential applications of nanotechnology in the food packaging industry are studied in the manuscript, in the field of antibacterial materials for food packaging. The ALD technique was used to synthesize vanadium (V)-doped TiO2 thin nanofilm on commercially available polypropylene (PP) food container to enhance an antibacterial activity for potential use in food packaging, to reduce spoilage, thereby, prolonging the food shelf- life. To better understand the ability and effectiveness of the antimicrobial packaging material of V-doped TiO2, to prevent the biofilm formation by dairy-associated pathogenic bacteria, the coated and uncoated PP containers with a fresh raw cow's milk were tested. We have illustrated the effectiveness of ALD Al2O3 + TiVOx nanocoating against populations of milk-borne pathogenic bacteria. [ABSTRACT FROM AUTHOR]

The escalating concern over conventional antibiotic resistance has emphasized the urgency in developing innovative antimicrobial agents. In recent times, metal−organic frameworks (MOFs) have garnered significant attention within the realm of antimicrobial research due to their multifaceted antimicrobial attributes, including the sustained release of intrinsic or exogenous antimicrobial components, chemodynamically catalyzed generation of reactive oxygen species (ROS), and formation of photogenerated ROS. This comprehensive review provides a thorough overview of the synthetic approaches employed in the production of MOF-based materials, elucidating their underlying antimicrobial mechanisms in depth. The focal point lies in elucidating the research advancements across various antimicrobial modalities, encompassing intrinsic component release system, extraneous component release system, auto-catalytical system, and energy conversion system. Additionally, the progress of MOF-based antimicrobial materials in addressing wound infections, osteomyelitis, and periodontitis is meticulously elucidated, culminating in a summary of the challenges and potential opportunities inherent within the realm of antimicrobial applications for MOF-based materials. Growing concerns about conventional antibiotic resistance emphasized the need for alternative antimicrobial solutions. Metal-organic frameworks (MOFs) have gained significant attention in antimicrobial research due to their diverse attributes like sustained antimicrobial components release, catalytic generation of reactive oxygen species (ROS), and photogenerated ROS. This review covers MOF synthesis and their antimicrobial mechanisms. It explores advancements in intrinsic and extraneous component release, auto-catalysis, and energy conversion systems. The paper also discusses MOF-based materials' progress in addressing wound infections, osteomyelitis, and periodontitis, along with existing challenges and opportunities. Given the lack of related reviews, our findings hold promise for future MOF applications in antibacterial research, making it relevant to your journal's readership. [Display omitted] [ABSTRACT FROM AUTHOR]

Cellulose-based antibacterial hydrogel has good biocompatibility, antibacterial performance, biodegradability, and other characteristics. It can be very compatible with human tissues and degradation, while its good water absorption and moisturizing properties can effectively absorb wound exudates, keep the wound moist, and promote wound healing. In this paper, the structural properties, and physical and chemical cross-linking preparation methods of cellulose-based antibacterial hydrogels were discussed in detail, and the application of cellulose-based hydrogels in the antibacterial field was deeply studied. In general, cellulose-based antibacterial hydrogels, as a new type of biomaterial, have shown good potential in antimicrobial properties and have been widely used. However, there are still some challenges, such as optimizing the preparation process and performance parameters, improving the antibacterial and physical properties, broadening the application range, and evaluating safety. However, with the deepening of research and technological progress, it is believed that cellulose-based antibacterial hydrogels will be applied and developed in more fields in the future. [ABSTRACT FROM AUTHOR]

Low‐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. [ABSTRACT FROM AUTHOR]

The creation of antibacterial nanocomposites that provide prolonged release of encapsulated drugs is of great interest for various fields of medicine (dentistry, tissue regeneration, etc.). This article demonstrates the possibility of creating such nanocomposites based on sodium alginate and drug-templated mesoporous silica nanocontainers (MSNs) loaded with two bioactive substances. Herein, we thoroughly study all stages of the process, starting with the synthesis of MSNs using antiseptic micelles containing the hydrophobic drug quercetin and ending with assessing the activity of the resulting composites against various microorganisms. The main emphasis is on studying the quercetin solubilization in antiseptic micelles as well as establishing the relationship between the conditions of MSN synthesis and micelle morphology and capacity. The effect of medium pH on the release rate of encapsulated drugs is also evaluated. It was shown that the MSNs contained large amounts of encapsulated drugs and that the rate of drug unloading depended on the medium pH. The incorporation of such MSNs into the alginate matrix allowed for a prolonged release of the drugs. [ABSTRACT FROM AUTHOR]

The development of a wound dressing with both antibacterial and healing-guiding functions is a major concern in the treatment of open and infected wounds. In this study, poly(hexamethylene biguanide) hydrochloride (PHMB) was loaded into a 3D silk fibroin (SF) scaffold based on electrostatic interactions between PHMB and SF, and PHMB/SF hybrid scaffolds were prepared via freeze-drying. The effects of the PHMB/SF ratio on the antibacterial activity and cytocompatibility of the hybrid scaffold were investigated. The results of an agar disc diffusion test and a bacteriostasis rate examination showed that when the mass ratio of PHMB/SF was greater than 1/100, the scaffold exhibited obvious antibacterial activity against E. coli and S. aureus. L-929 cells were encapsulated in the PHMB/SF scaffolds and cultured in vitro. SEM, laser scanning confocal microscopy, and CCK-8 assay results demonstrated that hybrid scaffolds with a PHMB/SF ratio of less than 2/100 significantly promoted cell adhesion, spreading, and proliferation. In conclusion, a hybrid scaffold with a PHMB/SF ratio of approximately 2/100 not only effectively inhibited bacterial reproduction but also showed good cytocompatibility and is expected to be usable as a functional antibacterial dressing for wound repair. [ABSTRACT FROM AUTHOR]

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Rui Yuan,1,* Yuwen Zhang,1,* Liqiong Liao,2 Yige Ge,1 Weichang Li,1 Qinghui Zhi1 1Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, 510030, People’s Republic of China; 2Biomaterials Research Center, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, 510515, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qinghui Zhi, Hospital of Stomatology, Guanghua School of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, 510055, People’s Republic of China, Email zhiqingh@mail.sysu.edu.cn Weichang Li, Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, 510055, People’s Republic of China, Email liwch57@mail.sysu.edu.cnBackground: Dentin caries remains a significant public concern, with no clinically viable material that effectively combines remineralization and antimicrobial properties. To address this issue, this study focused on the development of a bio-inspired multifunctional nanogel with both antibacterial and biomineralization properties.Methods: First, p(NIPAm-co-DMC) (PNPDC) copolymers were synthesized from N-isopropylacrylamide (NIPAm) and 2-methacryloyloxyethyl-trimethyl ammonium chloride (DMC). Subsequently, PNPDC was combined with γ-polyglutamic acid (γ-PGA) through physical cross-linking to form nanogels. These nanogels served as templates for the mineralization of calcium phosphate (Cap), resulting in Cap-loaded PNPDC/PGA nanogels. The nanogels were characterized using various techniques, including TEM, particle tracking analysis, XRD, and FTIR. The release properties of ions were also assessed. In addition, the antibacterial properties of the Cap-loaded PNPDC/PGA nanogels were evaluated using the broth microdilution method and a biofilm formation assay. The remineralization effects were examined on both demineralized dentin and type I collagen in vitro.Results: PNPDC/PGA nanogels were successfully synthesized and loaded with Cap. The diameter of the Cap-loaded PNPDC/PGA nanogels was measured as 196.5 nm at 25°C and 162.3 nm at 37°C. These Cap-loaded nanogels released Ca2+ and PO43- ions quickly, effectively blocking dental tubules with a depth of 10 μm and promoting the remineralization of demineralized dentin within 7 days. Additionally, they facilitated the heavy intrafibrillar mineralization of type I collagen within 3 days. Moreover, the Cap-loaded nanogels exhibited MIC50 and MIC90 values of 12.5 and 50 mg/mL against Streptococcus mutans, respectively, with an MBC value of 100 mg/mL. At a concentration of 50 mg/mL, the Cap-loaded nanogels also demonstrated potent inhibitory effects on biofilm formation by Streptococcus mutans while maintaining good biocompatibility.Conclusion: Cap-loaded PNPDC/PGA nanogels are a multifunctional biomimetic system with antibacterial and dentin remineralization effects. This strategy of using antibacterial nanogels as mineral feedstock carriers offered fresh insight into the clinical management of caries.Graphical Abstract: Keywords: nanomaterial, mineralization, antibacterial materials, dentinal tubule occlusion, caries

Photocatalytic antibacterial materials have been popularized and widely used in the disinfection of municipal water, the large-scale wastewater sterilization treatment of industry, and medical treatment. Their antibacterial theory has also been continuously studied and improved, and the reactive oxygen species (ROS) antibacterial mechanism has the highest acceptance by the public. The role of ROS is the main bactericidal mechanism of photocatalytic antibacterial agents, and it is also the mechanism explanation at the molecular level in the fields of organic pollutant degradation and biological pathology. ROS at an abnormal steady-state concentration attacks the organic structure outside the cell and enters the cell, causing oxidative stress reactions inside the cell and irreversible damage to the cell until apoptosis. Therefore, a systematic analysis of the production pathways, principle of action, and corresponding detection methods of active oxygen is of great importance for improving the antibacterial activity of photocatalytic antibacterial agents and exploring the antibacterial mechanism of active oxygen. First, this article introduces the production mechanism of active oxygen in photocatalytic materials and its antibacterial performance. Particularly, the modification method of constructing heterojunctions and introducing oxygen vacancies is the main way to increase active oxygen production. Second, this article summarizes the production process and mechanisms of the main ROS, such as the superoxide anion radical (·O\begin{document}${}_2^- $\end{document}), hydrogen peroxide (H2O2), singlet oxygen (1O2), and the hydroxyl radical (·OH), as well as the antibacterial process. Detection methods are summarized for four ROS, including direct methods and indirect methods as well the specific and selective reaction principle of probe molecules with ROS. Furthermore, the influencing factors of the total concentration of ROS excited by photocatalytic materials are sorted out, and a modification direction for producing ROS is proposed. This paper proposes the problems existing in the research on the action mechanism of ROS and the deficiencies in the detection methods of ROS and their specific interaction with cells. It is suggested to carefully analyze the antibacterial mechanism of ROS at the biological component level under the guidance of the generation chain of ROS and the dynamic balance system of various ROS. Finally, suggestions are made on the design and application of active oxygen antibacterial materials, and the development prospects are addressed.

Abstract Low‐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.

This study investigates the incorporation of active secondary amine moieties into the polymer backbone by co‐polymerizing 2,4,6‐tris(chloromethyl)‐mesitylene with three diamines, namely 1,4‐diaminobutane, m‐phenylenediamine, and p‐phenylenediamine. This process results in the stabilization of the amine moieties and the subsequently introduced nitroso groups. Charging bioactive nitric oxide (NO) into the polymers is accomplished by converting the amine moieties into N‐nitroso groups. The ability of the polymers to store and release NO depends on their structures, particularly the amount of incorporated active secondary amines. With grafting photosensitive N‐nitroso groups into the polymers, the derived NO@polymers exhibit photoresponsivity. NO release is completely regulated by adjusting UV light irradiation. These resulting polymeric NO donors demonstrate remarkable bactericidal and bacteriostatic activity, effectively eradicating E. coli bacteria and inhibiting their growth. The findings from this study hold promising implications for combining NO delivery with phototherapy in various medical applications. [ABSTRACT FROM AUTHOR]

The rapid rise of antibiotic resistance has become a critical global health concern, necessitating the development of alternative treatments, such as antibacterial nanoparticles (NPs). While the antibacterial potency of these NPs is known to depend highly on their surface chemistry, existing designs predominantly include NPs with uniform surface coatings. In this study, we present a distinctive approach to using the surface anisotropy of NPs to modulate their antibacterial efficacy. Specifically, we investigate the antibacterial properties of amphiphilic Janus nanoparticles (NPs), which display spatially separated hydrophobic and cationic ligands on opposing sides. By integrating experiments with molecular dynamics simulations, we unveil the crucial role of polycationic ligands in enhancing the interaction between Janus NPs and bacteria, ultimately leading to a significantly improved antibacterial potency. With hydrophobic and polycationic ligands spatially separated on a single NP surface, these amphiphilic Janus NPs effectively permeabilize the cell envelopes of both Gram-negative and Gram-positive bacteria. As a result, they inhibit bacterial growth at lower concentrations compared with NPs with uniform surface chemistry. Moreover, we demonstrate the versatility of the Janus NPs' antibacterial activity across various types of polycationic ligands. Our findings provide a mechanistic understanding of the spatial arrangement of ligands as well as the molecular characteristics of ligands in modulating NP–bacteria interactions. This research underscores the potential of Janus NPs, a distinctive subgroup of nanoparticles characterized by their anisotropic surface chemistry, as a unique class of antibacterial materials. [ABSTRACT FROM AUTHOR]

Polypropylene melt-blown nonwoven fabric (PP MNF) masks can effectively block pathogens in the environment from entering the human body. However, the adhesion of surviving pathogens to masks poses a risk of human infection. Thus, embedding safe and efficient antibacterial materials is the key to solving pathogen infection. In this study, stable chlorinated poly(methacrylamide-N,N′-methylenebisacrylamide) polypropylene melt-blown nonwoven fabrics (PP-P(MAA-MBAA)-Cl MNFs) have been fabricated by a simple UV cross-link and chlorination process, and the active chlorine content can reach 3500 ppm. The PP-P(MAA-MBAA)-Cl MNFs show excellent hydrophilic and antibacterial properties. The PP-P(MAA-MBAA)-Cl MNFs could kill all bacteria (both Escherichia coli and Staphylococcus aureus) with only 5 min of contact. Therefore, incorporating PP-P(MAA-MBAA)-Cl MNF as a hydrophilic antimicrobial layer into a four-layer PP-based mask holds great potential for enhancing protection and comfort. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) are fascinating materials for biomedical applications thanks to their strong antibacterial activity and biocompatibility. This study applied the green synthesis method using 0.5 wt.% Seminyak leaf extract and assisted with one min microwave irradiation to enhance AgNPs formation. Extremely small sizes AgNPs with an average particle size of 9.1 ± 4.1 nm and spherical shapes were obtained. The synthesized AgNPs displayed potent antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria with a zone of inhibition of 12.3 ± 0.1 and 13.7 ± 0.7 mm, respectively. The MTT assay results demonstrated that the cells’ viability of the obtained AgNPs was 88.5 ± 7.0 %, implying biocompatibility for biomedical applications.

Recent advancements in aggregation‐induced emission (AIE) macromolecular materials have brought their attention as potential antibacterial solutions, these materials offer new approaches to cure multidrug‐resistant infections and biofilms in bacterial infections as well as real‐time monitoring and specific targeting of bacteria. This review provides an overview of the three main categories of AIE macromolecular materials with antibacterial properties; namely AIE‐active polymers, AIEgen@polymer complexes, and clusterization‐triggered emission (CTE) based polymers. The mechanisms and applications of these materials in antibacterial treatment, wound care, and protective equipment are also discussed. The potential for future developments and application directions of AIE‐based antimicrobial materials are finally highlighted. [ABSTRACT FROM AUTHOR]

A novel supramolecular antibacterial agent (CHX-3CB[7]) based on the host–guest interaction between cucurbit[7]uril (CB[7]) and chlorhexidine (CHX) was successfully constructed, which exhibited improved antibacterial activity and relieved side effects. [Display omitted] Bacterial infection has emerged as a grievous threat to public health, and lots of antibacterial agents were developed to solve this issue. However, enhancing the antibacterial activity of antibacterial agents while reducing their side effects remains a challenge. Herein, a supramolecular antibacterial agent based on the host–guest interaction between cucurbit[7]uril (CB[7]) and chlorhexidine (CHX) was designed. CHX can be encapsulated in the cavity of CB[7] to form a 1:3 host–guest complex (CHX-3CB[7]). It was amazingly found that this supramolecular complex could display higher antibacterial activity than CHX alone. Electrospray mass spectrometry and UV–vis spectra revealed that the introduction of CB[7] promoted the protonation of N -atoms on CHX, resulting in stronger ion interaction with phospholipids and thus enhancing the destruction of the bacterial membrane. Scanning electron microscopy (SEM), surface ζ-potentials and outer/inner membrane integrity assays also reveal that the introduction of CB[7] aggravates the rupture of membrane. What is more, the cytotoxicity and irritation of CHX were decreased by forming the host–guest complex with CB[7]. This work provides a paradigm for enhancing antibacterial activity and reducing side effects of drugs through supramolecular chemistry. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) correspond to carbon‐based materials (CBM) with sizes usually below 10 nm. These nanomaterials exhibit attractive properties such us low toxicity, good stability, and high conductivity, which have promoted their thorough study over the past two decades. The current review describes four types of CDs: carbon quantum dots (CQDs), graphene quantum dots (GQDs), carbon nanodots (CNDs), and carbonized polymers dots (CPDs), together with the state of the art of the main routes for their preparation, either by "top‐down" or "bottom‐up" approaches. Moreover, among the various usages of CDs within biomedicine, we have focused on their application as a novel class of broad‐spectrum antibacterial agents, concretely, owing their photoactivation capability that triggers an enhanced antibacterial property. Our work presents the recent advances in this field addressing CDs, their composites and hybrids, applied as photosensitizers (PS), and photothermal agents (PA) within antibacterial strategies such as photodynamic therapy (PDT), photothermal therapy (PTT), and synchronic PDT/PTT. Furthermore, we discuss the prospects for the possible future development of large‐scale preparation of CDs, and the potential for these nanomaterials to be employed in applications to combat other pathogens harmful to human health. This article is categorized under:Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease [ABSTRACT FROM AUTHOR]

Commercial polyvinylidene fluoride (PVDF) microporous membranes are coated with P(AA‐co‐AM) hydrogel with different proportions of acrylic acid (AA) and acrylamide (AM). Thus, P(AA‐co‐AM)/PVDF membranes with good structure and excellent performance are prepared. The surface morphology and structure of P(AA‐co‐AM)/PVDF membranes are characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT‐IR). The water contact angle (WCA), underwater oil contact angle (UOCA), pure water flux, separation flux, and separation efficiency of P(AA‐co‐AM)/PVDF membranes are measured. The antibacterial properties of P(AA‐co‐AM)/PVDF membranes are tested, and the prepared membranes have good antibacterial activity against E. coli and S. aureus after chlorination. The prepared P(AA‐co‐AM)/PVDF membranes show good hydrophilicity and underwater oleophobicity, and improved separation performance of mud, oil–water emulsion, metal ions, and organic dyes. [ABSTRACT FROM AUTHOR]

Aims: the focus of this study is to evaluate if the combination of an antibiotic with a ceramic biomaterial is effective in treating osteomyelitis in an infected animal model and to define which model and protocol are best suited for in vivo experiments of local bone infection treatment. Methods: a systematic review was carried out based on PRISMA statement guidelines. A PubMed search was conducted to find original papers on animal models of bone infections using local antibiotic delivery systems with the characteristics of bone substitutes. Articles without a control group, differing from the experimental group only by the addition of antibiotics to the bone substitute, were excluded. Results: a total of 1185 records were retrieved, and after a three-step selection, 34 papers were included. Six manuscripts studied the effect of antibiotic-loaded biomaterials on bone infection prevention. Five articles studied infection in the presence of foreign bodies. In all but one, the combination of an antibiotic with bioceramic bone substitutes tended to prevent or cure bone infection while promoting biomaterial osteointegration. Conclusions: this systematic review shows that the combination of antibiotics with bioceramic bone substitutes may be appropriate to treat bone infection when applied locally. The variability of the animal models, time to develop an infection, antibiotic used, way of carrying and releasing antibiotics, type of ceramic material, and endpoints limits the conclusions on the ideal therapy, enhancing the need for consistent models and guidelines to develop an adequate combination of material and antimicrobial agent leading to an effective human application. [ABSTRACT FROM AUTHOR]

Wound infection is arguably the most common, and potentially the most devastating, complication of the wound healing process. The ideal treatment strategy has to eliminate bacteria, alleviate inflammation, and promote wound healing and skin formation. Herein, a multifunctional heterostructure is designed consisting of ultrasmall platinum–ruthenium nanoalloys and porous graphitic carbon nitride C3N5 nanosheets (denoted as PtRu/C3N5), which concurrently possesses piezoelectric enhanced oxidase ‐mimic nanozyme activity and photocatalytic hydrogen gas production capacity. Moreover, these hybrid nanotherapeutics are integrated in natural hyaluronic acid microneedles, which exhibit almost 100% broad‐spectrum antibacterial efficacy against multiple bacterial strains in vitro and in vivo within 10 min ultrasound treatment, and effectively inhibit inflammation reactions after 1 h visible light irradiation, promising for accelerating the cutaneous wound healing in the bacterial infected mice. This study highlights a competitive strategy for development of all‐in‐one antibacterial and anti‐inflammatory therapies. [ABSTRACT FROM AUTHOR]

Antibiotic resistance of bacteria and persistent inflammation are critical challenges in treating bacteria infected wounds. Thus, it is urgent to develop versatile wound dressings that possess high-efficiency antibacterial performance and inflammation regulation. Herein, we have successfully constructed a hydrogel wound dressing consisting of the bimetallic metal-organic framework (MOF) loaded with glucose oxidase (GOx), termed as MOF(Fe-Cu)/GOx-polyacrylamide (PAM) gel. Hydrogel dressings can provide an efficient cascade-catalyzed system to accelerate wound healing via synergistic antibacterial and inflammatory modulation. Importantly, the catalytic property of the bimetallic MOF(Fe-Cu) is about five times that of the monometallic MOF(Fe). Based on such a cascade-catalyzed system, the abundant gluconic acid and H 2 O 2 can be continuously produced by decomposing glucose via GOx. Such gluconic acid can notably improve the peroxidase performance of MOF(Fe-Cu), which can further efficiently decompose H 2 O 2 to achieve the antibacterial. Meanwhile, MOF (Fe Cu)/GOx PAM gel can induce macrophages to change into an M2 phenotype, which can accelerate the transformation of the wound microenvironment to a remodeling state and then accelerate angiogenesis and neurogenesis. This work provides multifunctional bioactive materials for accelerating wound healing and will have great potential in clinical applications. Antibiotic resistance and persistent inflammation are still the critical reasons for the slow healing of bacteria infected wounds. Herein, we prepared a hydrogel wound dressing composed of bimetallic metal organic framework (MOF) loaded with glucose oxidase (GOx). The catalytic activity of the bimetallic MOF(Fe-Cu) is significantly enhanced due to doping of copper, which makes it possess outstanding antibacterial ability based on cascade catalysis. Such dressing can promote the remodeling of inflammatory immunity by regulating macrophage polarization to suppress over-reactive inflammation, further accelerating the healing of bacteria-infected wounds. This study provides an innovative and effective way to accelerate the healing of bacteria infected wound by combining bacteria killing and inflammation modulation. [Display omitted] [ABSTRACT FROM AUTHOR]

Cellulose-based antibacterial hydrogel has good biocompatibility, antibacterial performance, biodegradability, and other characteristics. It can be very compatible with human tissues and degradation, while its good water absorption and moisturizing properties can effectively absorb wound exudates, keep the wound moist, and promote wound healing. In this paper, the structural properties, and physical and chemical cross-linking preparation methods of cellulose-based antibacterial hydrogels were discussed in detail, and the application of cellulose-based hydrogels in the antibacterial field was deeply studied. In general, cellulose-based antibacterial hydrogels, as a new type of biomaterial, have shown good potential in antimicrobial properties and have been widely used. However, there are still some challenges, such as optimizing the preparation process and performance parameters, improving the antibacterial and physical properties, broadening the application range, and evaluating safety. However, with the deepening of research and technological progress, it is believed that cellulose-based antibacterial hydrogels will be applied and developed in more fields in the future.

Bacterial infections are a serious threat to human health, and the rapid emergence of bacterial resistance caused by the abuse of antibiotics exacerbates the seriousness of this problem. Effectively utilizing natural products to construct new antimicrobial strategies is regarded as a promising way to suppress the rapid development of bacterial resistance. In this paper, we fabricated a new type of natural antibacterial patch by using a natural active substance (allicin) as an antibacterial agent and the porous structure of the white pulp of pomelo peel as a scaffold. The antibacterial activity and mechanisms were systematically investigated by using various technologies, including the bacteriostatic circle, plate counting, fluorescence staining, and a scanning electron microscope. Both gram-positive and negative bacteria can be effectively killed by this patch. Moreover, this natural antibacterial patch also showed significant anti-skin infection activity. This study provides a green approach for constructing efficient antibacterial patches. [ABSTRACT FROM AUTHOR]

Post-COVID-19, the risk and spread of germs, coupled with wastewater contamination, have become critical concerns. Wastewater contains waterborne bacteria and various contaminants like dye molecules, threatening water safety. Traditional adsorption methods address pollutant removal or pathogen inactivation separately, but a dual-action solution is increasingly essential. This study presents alginate/selenium composite hydrogel beads with the potential to simultaneously remove dyes and deactivating bacteria. Fabricated by dropping suspension droplets into a calcium ion bath, these beads were tested for dye adsorption and antibacterial efficacy. Beads with 50 wt% organo‑selenium demonstrated the highest methylene blue (MB) adsorption capacity and nearly 100 % deactivation efficiency against Pseudomonas aeruginosa , while those with 20 wt% showed no significant improvement. Mechanistic studies reveal that organo‑selenium induces stacking effects and reduces surface charges, enhancing MB adsorption and antibacterial performance. The alginate/organo‑selenium composite hydrogel beads offer a potential effective and sustainable solution for tackling the complex issue of wastewater pollutants. [Display omitted] [ABSTRACT FROM AUTHOR]

Severe bleeding and bacterial infections pose significant challenges to the global public health. Effective hemostatic materials have the potential to be used for rapid control of bleeding at the wound site. In this study, mesoporous silica nanoparticles (MSN) were doped with zinc ions (MSN@Zn) and subsequently functionalized with carboxyl (-COOH) groups through post-grafting, resulting in (MSN@Zn-COOH). The results demonstrated the successful functionalization of carboxyl groups on the surface of MSN@Zn mesoporous materials with minimal impact on the morphology. The released zinc ions showed potent antibacterial activity (above ∼80 %) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In vitro and in vivo assessments of MSN@Zn-COOH revealed excellent hemostatic effects and favorable blood compatibility. Hemolysis percentages associated with MSN@Zn-COOH exhibited noteworthy reductions in comparison to MSN. Furthermore, a decrease in APTT (a test evaluating the intrinsic coagulation pathway) of modified MSN@Zn indicated enhanced hemostasis, supported by their negative zeta potential (∼ –14 to –43 mV). Importantly, all samples showed no cytotoxicity. This work underscores the potential of MSN@Zn-COOH, with its combined hemostatic performance and antibacterial activity, for emergency clinical applications. [Display omitted] • Mesoporous silica nanoparticles (MSN) as a hemostatic agent were incorporated with Zn ions (MSN@Zn) to improve antibacterial activities. • MSN@Zn functionalized with carboxyl groups through post-grafting, resulting in (MSN@Zn-COOH) to enhance the hemostatic efficacy. • MSN@Zn-COOH demonstrated good hemocompatibility and its hemostatic time was significantly shorter than that of MSN. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver-doped ZnS QDs boost ROS generation under ultrasound. • TN-HHTZ targets infection sites precisely, enabling focused drug delivery. • HHTZ forms a gel at infection sites, enabling sustained antimicrobial effects. • TN-HHTZ enhances bone regeneration and improving recovery at the implant site. • TN-HHTZ as an implant antimicrobial strategy reduces bacterial resistance. Sonodynamic therapy (SDT) is extensively utilized for its profound tissue penetration capabilities in treating deep-seated infections, yet achieving precise ultrasonic treatment at the implant surface remains challenging. Herein, details the development of a novel infection microenvironment-sensitive nano-interface (TN-HHTZ), aimed at enhancing SDT efficacy for treating implant-related infections. The ZnS:Ag quantum dots (ZnS:Ag QDs) are functionalized using tyramine-modified hyaluronic acid (HA-Tyr) and horseradish peroxidase (HRP), resulting in the formation of a hydrogen peroxide (H 2 O 2)-sensitive composite sonosensitizer (HHTZ). HHTZ is loaded onto a titanium dioxide nanotube (TN) array to form TN-HHTZ. Upon infection, ultrasonic triggering causes the rapid release of HHTZ, which interacts with H 2 O 2 in the infected area to form a gel, thereby enabling prolonged enrichment of ZnS:Ag QDs at the site of implant infection. The doping of Ag in ZnS:Ag QDs enhances energy conversion, enabling TN-HHTZ to generate a significant amount of reactive oxygen species (ROS) during the SDT process, thereby boosting its antimicrobial efficacy and ensuring sustained antimicrobial activity throughout the infection period. The TN-HHTZ hydrogel on the implant surface promotes bone cell proliferation and recovery, providing an innovative and holistic strategy for treating and recovering from implant-associated microbial infections. [ABSTRACT FROM AUTHOR]

The rise in petroleum-based plastic waste, driven by increased consumption from delivery services and e-commerce, necessitates the search for sustainable alternatives like alginate-based materials to mitigate environmental risks. However, alginate, a biopolymer, has limited physico-chemical properties, lacks antibacterial capacity, and exhibits low antiviral activity. To address these issues, this study synthesized Cu 3 Mo 2 O 9 semiconductor nanoparticles (CMO) and integrated them into alginate films crosslinked with Ca2+, producing advanced nanocomposite films with varying nanoparticle concentrations (0–10 wt%). CMO nanoparticles release Cu2+ and Mo6+ ions and generate reactive oxygen species (ROS), even in the dark. Results show that CMO weakly interacts with alginate blocks, causing slight structural changes but not significantly altering mechanical or thermal properties. CMO released Cu2+ (150–250 ppb at 24 h) and Mo6+ ions (5–8 ppm at 24 h), with Cu2+ undergoing cation exchange with Ca2+ crosslinking ions. Antibacterial tests demonstrated the composites' effectiveness against Gram-negative Pseudomonas aeruginosa (97.30 % and 91.36 % growth inhibition at 5 % and 10 % CMO), Gram-positive methicillin-resistant Staphylococcus aureus (87.26 % and 96.82 % inhibition at 5 % and 10 % CMO), and Mycobacterium smegmatis (99.83 % and 99.97 % inhibition at 5 % and 10 % CMO). These composites also showed antiviral activity against bacteriophage phi 6 (99.81 % and 92.66 % inactivation at 5 % and 10 % CMO) and bacteriophage MS2 (92.32 % and 92.93 % inactivation at 5 % and 10 % CMO). The primary mechanism is attributed to the release of Cu2+ cations and ROS generation. These nanocomposite films exhibit broad-spectrum antimicrobial activity, offering potential industrial applications in packaging and antimicrobial surfaces. [Display omitted] • Cu₃Mo₂O₉ nanoparticles were synthesized and encapsulated in Ca2+-crosslinked alginate films. • Composite films exhibited broad-spectrum antibacterial and antiviral properties. • Antimicrobial activity attributed to ROS generation and ionic release. [ABSTRACT FROM AUTHOR]

The smaller the particle size of Ag nanoparticles, the higher their antibacterial activity against drug-resistant strains, and the greater their potential for application in living organisms. Therefore, preparing Ag nanoparticles with ultra-small particle sizes has become one of the greatest challenges at present. In this study, 1.75 nm Ag was uniformly anchored on the surface of a highly biocompatible carrier to synthesize Fe 3 O 4 /ZnO@Cu 2 S@Ag (FCA) nanocomposites. The antibacterial activity and mechanism of FCA were investigated, and the material was used to treat wound infections caused by bacteria. At a concentration of 175 μg/mL, the antibacterial rate of Escherichia coli , Staphylococcus aureus , and drug-resistant Salmonella was over 99.99 % within 45 min. The antibacterial activity is mainly composed of •OH and multiple cations. The antibacterial mechanism involves •OH and multiple cations synergistically targeting and damaging the bacterial cell wall, altering the secondary structure of the bacterial cell wall, leading to leakage of bacterial contents and bacterial death. Additionally, FCA exhibited high biocompatibility, curing bacterial infections within 7 days and completely eliminating bacterial burden. These findings elucidate the role of antibacterial activity in composite antibacterial materials and suggest that FCA has clinical application potential in treating bacterial infections. [Display omitted] • The Fe 3 O 4 /ZnO@Cu 2 S@Ag nanocomposites was prepared. • The nanocomposites achieved outstanding antibacterial capacity. • The bacterial cell wall is targeted and damaged by the Fe 3 O 4 /ZnO@Cu 2 S@Ag. [ABSTRACT FROM AUTHOR]

Polypropylene melt-blown nonwoven fabric (PP MNF) masks can effectively block pathogens in the environment from entering the human body. However, the adhesion of surviving pathogens to masks poses a risk of human infection. Thus, embedding safe and efficient antibacterial materials is the key to solving pathogen infection. In this study, stable chlorinated poly(methacrylamide-N,N′-methylenebisacrylamide) polypropylene melt-blown nonwoven fabrics (PP-P(MAA-MBAA)-Cl MNFs) have been fabricated by a simple UV cross-link and chlorination process, and the active chlorine content can reach 3500 ppm. The PP-P(MAA-MBAA)-Cl MNFs show excellent hydrophilic and antibacterial properties. The PP-P(MAA-MBAA)-Cl MNFs could kill all bacteria (both Escherichia coli and Staphylococcus aureus) with only 5 min of contact. Therefore, incorporating PP-P(MAA-MBAA)-Cl MNF as a hydrophilic antimicrobial layer into a four-layer PP-based mask holds great potential for enhancing protection and comfort.

The creation of antibacterial nanocomposites that provide prolonged release of encapsulated drugs is of great interest for various fields of medicine (dentistry, tissue regeneration, etc.). This article demonstrates the possibility of creating such nanocomposites based on sodium alginate and drug-templated mesoporous silica nanocontainers (MSNs) loaded with two bioactive substances. Herein, we thoroughly study all stages of the process, starting with the synthesis of MSNs using antiseptic micelles containing the hydrophobic drug quercetin and ending with assessing the activity of the resulting composites against various microorganisms. The main emphasis is on studying the quercetin solubilization in antiseptic micelles as well as establishing the relationship between the conditions of MSN synthesis and micelle morphology and capacity. The effect of medium pH on the release rate of encapsulated drugs is also evaluated. It was shown that the MSNs contained large amounts of encapsulated drugs and that the rate of drug unloading depended on the medium pH. The incorporation of such MSNs into the alginate matrix allowed for a prolonged release of the drugs.

The development of a wound dressing with both antibacterial and healing-guiding functions is a major concern in the treatment of open and infected wounds. In this study, poly(hexamethylene biguanide) hydrochloride (PHMB) was loaded into a 3D silk fibroin (SF) scaffold based on electrostatic interactions between PHMB and SF, and PHMB/SF hybrid scaffolds were prepared via freeze-drying. The effects of the PHMB/SF ratio on the antibacterial activity and cytocompatibility of the hybrid scaffold were investigated. The results of an agar disc diffusion test and a bacteriostasis rate examination showed that when the mass ratio of PHMB/SF was greater than 1/100, the scaffold exhibited obvious antibacterial activity against E. coli and S. aureus. L-929 cells were encapsulated in the PHMB/SF scaffolds and cultured in vitro. SEM, laser scanning confocal microscopy, and CCK-8 assay results demonstrated that hybrid scaffolds with a PHMB/SF ratio of less than 2/100 significantly promoted cell adhesion, spreading, and proliferation. In conclusion, a hybrid scaffold with a PHMB/SF ratio of approximately 2/100 not only effectively inhibited bacterial reproduction but also showed good cytocompatibility and is expected to be usable as a functional antibacterial dressing for wound repair.

Textile materials modified with copper-containing particles have antibacterial and antiviral properties that have prospects for use in healthcare. In the study, textile materials were saturated with copper-containing particles in their entire material volume by the absorption/diffusion method. The antibacterial properties of modified textile materials were confirmed by their inhibitory effect on Staphylococcus aureus, a Gram-positive bacterium that spreads predominantly through the respiratory tract. For the modification, ordinary textile materials of various origins and fiber structures were used. Technological conditions and compositions of modifying solutions were established, as well as the most suitable textile materials for modification. To assess the morphological and physical characteristics of copper-containing particles and the textile materials themselves, X-ray diffraction, a scanning electron microscope, and an energy-dispersive X-ray spectrum were used. In modified textile samples, XRD data showed the presence of crystalline phases of copper (Cu) and copper (I) oxide (Cu2O). On the grounds of the SEM/EDS analysis, the saturation of textile materials with copper-containing particles depends on the structure of the textile materials and the origins of the fibers included in their composition, as well as the modification conditions and the copper precursor. [ABSTRACT FROM AUTHOR]

In this study, nanofiber surfaces were produced from a mixture of polyvinyl alcohol and silk sericin protein (PVA:SS) containing gelatin-coated silver nanoparticles (G-AgNPs) by electrospinning. For preparation of G-AgNPs, gelatin solution (1%, w/v) was mixed with 5 mM of AgNO3 solution and the mixture was heated and stirred for 2 h. AgNPs production has been observed with the brown color change that occurred in the solution. The absorbance of G-AgNPs was measured with a UV–Vis spectroscopy in the 300–700 nm range, and it was proved that AgNPs were formed with the surface plasmon resonance peak observed at 420 nm. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray analysis (EDS) analyses revealed that G-AgNPs were in spherical form and contained C, H, N, Ag elements in their structures, respectively. Antibacterial activity of the synthesized of G-AgNPs was shown with agar well diffusion test against to Escherichia coli and Staphylococcus aureus bacteria. In the second stage of the study, PVA:SS solutions were turned into nanofibers by electrospinning at certain conditions. G-AgNPs solutions were added in 3 different ratios of 10, 20 and 30% by volume to PVA:SS solutions, and these mixtures were turned into nanofibers with the same conditions. It has been shown by Fourier transform infrared spectroscopy (FTIR) analyses that the nanofiber surfaces obtained were composed of PVA:SS blend. The morphologies of nanofiber surfaces were investigated by FESEM analysis, and compared to PVA nanofibers collected alone, the fiber diameters of the groups containing PVA, sericin and G-AgNPs were found to be much lower. The presence of silver in nanofibers containing G-AgNPs was proven by EDS and X-ray fluorescence analyses. The thermal properties of nanofiber surfaces were investigated by thermogravimetric analysis, and it was observed that the thermal stability of nanofiber surfaces increased with the addition of sericin and G-AgNPs to PVA. Then, liquid medium tests were performed for finding the antibacterial activity of nanofiber surfaces containing various proportions of G-AgNPs on E. coli and S. aureus bacteria, and it was observed that nanofiber surfaces containing certain amounts of G-AgNPs inhibited the growth of both bacteria. It is thought that the functional and antibacterial surfaces obtained in the study will have the capacity to be used in many different areas such as wound dressing material. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian Polytechnic University is the property of Journal of Dalian Polytechnic University Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A series of poly(2-hydroxyethyl methacrylate) (PHEMA) thin films entrapping photosensitizer Rose Bengal (RB) and tetrabutylammonium iodide (TBAI) have been synthetized. The materials have been characterized by means of Thermogravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and UV-vis Absorption spectroscopy. Irradiation of the materials with white light led to the generation of several bactericidal species, including singlet oxygen (1O2), triiodide anion (I3−) and hydrogen peroxide (H2O2). 1O2 production was demonstrated spectroscopically by reaction with the chemical trap 2,2′-(anthracene-9,10-diylbis(methylene))dimalonic acid (ABDA). In addition, the reaction of iodide anion with 1O2 yielded I3− inside the polymeric matrix. This reaction is accompanied by the formation of H2O2, which diffuses out the polymeric matrix. Generation of both I3− and H2O2 was demonstrated spectroscopically (directly in the case of triiodide by the absorption at 360 nm and indirectly for H2O2 using the xylenol orange test). A series of photodynamic inactivation assays were conducted with the synthesized polymers against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Complete eradication (7 log10 CFU/mL) of both bacteria occurred after only 5 min of white light irradiation (400–700 nm; total energy dose 24 J/cm2) of the polymer containing both RB and TBAI. The control polymer without embedded iodide (only RB) showed only marginal reductions of ca. 0.5 log10 CFU/mL. The main novelty of the present investigation is the generation of three bactericidal species (1O2, I3− and H2O2) at the same time using a single polymeric material containing all the elements needed to produce such a bactericidal cocktail, although the most relevant antimicrobial activity is shown by H2O2. This experimental approach avoids multistep protocols involving a final step of addition of I−, as described previously for other assays in solution. [ABSTRACT FROM AUTHOR]

To solve the current and future mask shortage problems, developing methods of disinfecting respirators is essential, where none of the existing methods have been successfully utilized until recently. Herein, we introduce a novel method of conferring antibacterial activity to the main filtering material (i.e., polypropylene (PP)) of a respirator through sequential polydopamine (PDA) coatings. Two-step dip-coating in dopamine solution, which corresponds to one complete cycle, produces stable PDA films at the interface of the filtering material, which subsequently locally generates H2O2 that can be further transformed into hydroxyl radicals to inactivate pathogens. Specifically, the primary dip-coating creates a scaffold PDA film that acts as a mechanical support, and anchoring dopamine, which substantially produces H2O2, is immobilized to the scaffold PDA during the subsequent secondary dip-coating process. The antibacterial activity was confirmed by bacterial tests using Escherichia coli. In short, the number of colonies after incubation of the polypropylene filter with and without the PDA coating in the bacterial solution was compared. The number of bacteria in the PDA-coated sample (0.54 × 109 CFU/mL·cm2) was significantly reduced compared to that in the original PP sample (0.81 × 109 CFU/mL·cm2), demonstrating a positive relationship with the H2O2 production. Moreover, this antibacterial ability can be maintained by simply utilizing additional PDA coatings, suggesting that the respirators can be recycled. Finally, the in vitro cytotoxicity was confirmed by the CCK-8 assay, which demonstrated that the PDA-coated PP filter is biocompatible. We believe that the newly proposed method for disinfection of respirators may substitute conventional methods and can be used to alleviate the mask shortage problem. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Defect engineering is an exciting tool for customizing semiconductors' structural and optoelectronic properties. Elaborating programmable methodologies to circumvent energy constraints in multievent inversions expands our understanding of the mechanisms governing the functionalization of nanomaterials. Herein, we introduce a novel strategy based on defect incorporation and solution rationalization, which triggers energetically unfavorable cation exchange reactions in extended solids. Using Sb 2 X 3 + Ag (I) → Ag: Sb 2 X 3 (X= S, Se) as a system to model, we demonstrate that incorporating chalcogen vacancies and Ag Sb V X complex defects into initial thin films (TFs) is crucial for activating long-range solid-state ion diffusion. Additional regulation of the Lewis acidity of auxiliary chemicals provides an exceptional conversion yield of the Ag precursor into a solid-state product up to 90%, simultaneously transforming upper matrix layers into AgSbX 2 . The proposed strategy enables tailoring radiative recombination processes, offers efficiency to invert TFs at moderate temperatures quickly, and yields structures of large areas with substantial antibacterial activity in visible light for a particular inversion system. Similar customization can be applied to most sulfides/selenides with controlled reaction yields.