Outstanding Antibacterial Activity Research Articles

Batch preparation and characterization of zein-based beaded nanofiber membranes for active food packaging

Active packaging can efficiently enhance the shelf life of food, realizing the encapsulation and effective release of antibacterial agents and antioxidants. Zein is a natural protein derived from corn, widely used in food packaging. In this work, zein-based nanofiber membranes (NFMs) with beaded structures for food packaging were fabricated in batch using a self-made free surface electrospinning. The characteristics of NFMs were investigated in terms of their morphologies, structures and properties. The results illustrated that the antioxidant activity of NFMs was significantly improved after adding licorice extracts. Moreover, after adding the eugenol to the zein/licorice extract NFMs, zein/licorice extract/eugenol (ZLE) NFM had outstanding antibacterial activities against Staphylococcus aureus and Escherichia coli, which effectively prolonged the shelf-life of the grapes when it was used to package grapes. It proved that ZLE NFM had great potential in food packaging applications.

Whole-cell biocatalysis for ε-poly-l-lysine production by a food-grade recombinant Bacillus subtilis

ε-Poly-l-lysine (ε-PL), a natural food preservative with various advantages, is primarily produced by Streptomyces. It has attracted considerable attentions for the outstanding antibacterial activity, safety, heat stability, water solubility and other remarkable properties. In this study, a food-grade recombinant Bacillus subtilis was constructed for the biocatalysis of ε-PL. Firstly, the d-alanine racemase gene (alrA) was deleted from the genome of Bacillus subtilis 168 to construct an auxotrophic B. subtilis 168 (alrA-). Based on the shuttle plasmid pMA5, a food-grade plasmid pMA5a was constructed by replacing the genes of kanamycin resistance (Kanr) and ampicillin resistance (Ampr) with alrA and the gene encoding α-peptide of β-galactosidase (lacZα), respectively. Subsequently, codon-optimized ε-PL synthase gene (pls) and P-pls were ligated into pMA5a and transformed in E. coli DH5α and expressed in B. subtilis 168 (alrA-). Finally, the whole-cell biocatalysis conditions for ε-PL production by B. subtilis 168 (alrA-)/pMA5a-pls were optimized, and the optimal conditions were 30°C, pH 4, l-lysine concentration of 0.6 g/L, bacterial concentration of 15 % (w/v) and a catalytic time of 7 h. The ε-PL production reached a maximum of 0.33 ± 0.03 g/L. The product was verified to be ε-PL by HPLC and tricine-SDS-PAGE. The information obtained in this study shows critical reference for the food-grade heterologous expression of ε-PL.

Biomaterial-based sponge for efficient and environmentally sound removal of bacteria from water

Designing materials capable of disinfecting water without releasing harmful by-products is an ongoing challenge. Here, we report a novel polycationic sponge material synthesized from chitosan derivatives and cellulose fibers, exhibiting antibacterial properties. The design of such material is based on three key principles. First, the formation of a highly porous structure through cryogelation for an extensive surface area. Second, the incorporation of cationic quaternary ammonium moieties onto chitosan to enhance bacterial adsorption and antibacterial activity. Lastly, the reinforcement of mechanical properties through integration of cellulose fibers. The presented sponge materials exhibit up to a 4-log (99.99%) reduction within 6 h against both gram-positive B. subtilis and gram-negative E. coli. Notably, QCHI90/Cell, with the highest surface charge, exhibits a 2–4.5 log reduction within 1 h of incubation time. The eco-friendly synthesis from water and readily available biomaterials, along with cost-effectiveness and simplicity, underscores its versatility and feasibility of upscaling. Together with its outstanding antibacterial activity, this macroporous biomaterial emerges as a promising candidate for water disinfection applications.

Solvent-Induced Lignin Conformation Changes Affect Synthesis and Antibacterial Performance of Silver Nanoparticle.

The emergence of antibiotic-resistant bacteria necessitates the development of novel, sustainable, and biocompatible antibacterial agents. This study addresses cytotoxicity and environmental concerns associated with traditional silver nanoparticles (AgNPs) by exploring lignin, a readily available and renewable biopolymer, as a platform for AgNPs. We present a novel one-pot synthesis method for lignin-based AgNPs (AgNPs@AL) nanocomposites, achieving rapid synthesis within 5 min. This method utilizes various organic solvents, demonstrating remarkable adaptability to a wide range of lignin-dissolving systems. Characterization reveals uniform AgNP size distribution and morphology influenced by the chosen solvent. This adaptability suggests the potential for incorporating lignin-loaded antibacterial drugs alongside AgNPs, enabling combined therapy in a single nanocomposite. Antibacterial assays demonstrate exceptional efficacy against both Gram-negative and Gram-positive bacteria, with gamma-valerolactone (GVL)-assisted synthesized AgNPs exhibiting the most potent effect. Mechanistic studies suggest a combination of factors contributes to the antibacterial activity, including direct membrane damage caused by AgNPs and sustained silver ion release, ultimately leading to bacterial cell death. This work presents a straightforward, adaptable, and rapid approach for synthesizing biocompatible AgNPs@AL nanocomposites with outstanding antibacterial activity. These findings offer a promising and sustainable alternative to traditional antibiotics, contributing to the fight against antibiotic resistance while minimizing environmental impact.

In-Situ Synthesis of CuO/TiO2 Nanocomposite Onto Amine Modified Cotton Fabric for Antibacterial Durability and UV Protection

ABSTRACT In this research work, we explore antibacterial activity and the UV-protection of cotton fabric functionalized with copper oxide-titanium dioxide nano composites particles (CuO+TiO2 NCPs). Cotton fabrics (Cot) were treated with L-methionine (Am) and functionalized with bimetallic CuO+TiO2 NCPs by pad and rolling technique. Cu(NO3)2 and titanium isopropoxide (TIP) were used as sources of Cu(OH)2 and TiO2 colloid respectively, which were then converted into CuO and TiO2 nanoparticles (NPs) for making antibacterial and UV-protective cotton. The method yielded a crystallite size of CuO and TiO2 NPs of 18.09 and 32.5 nm, respectively. FTIR, Raman spectroscopy, High-resolution scanning electron microscopy-Energy dispersive Spectroscopy (HRSEM), (EDS), X-ray photo spectroscopy (XPS), thermal gravimetric analysis (TGA), and XRD were used to analyze the functional group, morphology, chemical composition, thermal stability and crystalline structure of the functionalized cotton fabric samples. The results showed that an esterification reaction occurred between Am and OH in cotton fabric, which further enhanced the binding of NCPs. AmCot-CuO+TiO2 NCPs exhibit outstanding antibacterial activity against gram-positive S. aureus and gram-negative E. coli. The UV protection factor (UPF) for AmCot-CuO+TiO2 NCPs reached 50+; thus, multifunctional cotton fabrics with excellent antibacterial and anti-ultraviolet properties were obtained.

The best African plant-derived antibacterial products for clinical perspectives: The state-of-the-art

Background: The global burden of bacterial infections remains a serious health concern. In the present review, we have summarized the best botanicals and phytochemicals from the flora of Africa that deserve clinical studies to develop novel antibacterial drugs to combat enterobacteria, Pseudomonas aeruginosa, Gram-positive bacteria, and mycobacteria. Methods: Data were retrieved from scientific databases such as PubMed, Scopus, ScienceDirect, Google Scholar, and Web of Science using the keywords “African country and plant and antibacterial” and plants or phytochemicals with outstanding antibacterial activities following established cutoff point standards were selected. Results: The identified botanicals were from Acacia polyacantha, Alchornea floribunda, Artemisia abyssinica, Beilschmiedia acuta, Eriosema glomeratum, Harungana madagascariensis, Macaranga capensis, Macaranga conglomerata, Macaranga kilimandscharica, Mangifera indica, Piper nigrum, Piptadeniastrum africanum, and Uapaca togoensis. The phytochemicals identified included 2-(4-hydroxyphenyl)-ethyltriacontanoate (1), 1,3,5,6-tetrahydroxyxanthone (2), 1,3,5,7-tetrahydroxyxanthone (3), 8,8-bis-(dihydroconiferyl) diferulate (4), 2-hydroxy-3-methoxy-9,10-dioxo-9,10-dihydroanthracene-1-carbaldehyde (5), allanxanthone D (6), angusticornin B (7), bartericin A (8), diospyrone (9), dorsmanin C (10), gancaonin Q (11), isobavachalcone (12), isoliquiritigenin (13), laburnetin (14), O1-demethyl-3',4'-deoxy-psorospermi-3',4' diol (15), plumbagin (16), and vismiaquinone (17). Conclusion: These plant-derived products deserve clinical investigations to develop novel antibacterial agents to combat bacterial infections.

Iodine/soluble starch cryogel: An iodine-based antiseptic with instant water-solubility, improved stability, and potent bactericidal activity

Iodine (I2) as a broad-spectrum antiseptic has been widely used for treating bacterial infections. However, I2 has low water-solubility and sublimes under ambient conditions, which limits its practical antibacterial applications. The highly specific and sensitive reaction between I2 and starch discovered 200 years ago has been extensively applied in analytical chemistry, but the antibacterial activity of the I2–starch complex is rarely investigated. Herein, we develop a novel type of iodine-based antiseptics, iodine−soluble starch (I2-SS) cryogel, which can dissolve in water instantly and almost completely kill bacteria in 10 min at 2 μg/mL of I2. Although KI3 and the commercially available povidone‑iodine (I2-PVP) solutions show similar antibacterial efficacy, the high affinity of I2 to SS largely enhances the shelf stability of the I2-SS solution with ∼73 % I2 left after one-week storage at room temperature. In sharp contrast, ∼8.5 % and ∼2.5 % I2 are detected in KI3 and I2-PVP solutions, respectively. Mechanistic study reveals that the potent antibacterial effect of I2-SS originates from its attack on multiple bacterial targets. The outstanding antibacterial activity, capability of accelerating wound healing, and good biocompatibility of I2-SS are verified through further in vivo experiments. This work may promote the development of next-generation iodine-based antiseptics for clinical use.

Advanced Multifunctional Hydrogels for Enhanced Wound Healing through Ultra-Fast Selenol-SNAr Chemistry.

Fabrication of versatile hydrogels in a facile and effective manner represents a pivotal challenge in the field of biomaterials. Herein, a novel strategy is presented for preparing on-demand degradable hydrogels with multilevel responsiveness. By employing selenol-dichlorotetrazine nucleophilic aromatic substitution (SNAr) to synthesize hydrogels under mild conditions in a buffer solution, the necessity of additives or posttreatments can be obviated. The nucleophilic and redox reactions between selenol and tetrazine culminate in the formation of three degradable chemical bonds-diselenide, aryl selenide, and dearomatized selenide-in a single, expeditious step. The resultant hydrogel manifests exceptional adaptability to intricate environments in conjunction with self-healing and on-demand degradation properties. Furthermore, the resulting material demonstrated light-triggered antibacterial activity. Animal studies further underscore the potential of integrating metformin into Se-Tz hydrogels under green light irradiation, as it effectively stimulates angiogenesis and collagen deposition, thereby fostering efficient wound healing. In comparison to previously documented hydrogels, Se-Tz hydrogels exhibit controlled degradation and drug release, outstanding antibacterial activity, mechanical robustness, and bioactivity, all without the need for costly and intricate preparation procedures. These findings underscore Se-Tz hydrogels as a safe and effective therapeutic option for diabetic wound dressings.

Antimicrobial nanolayer films of chloroxylenol–carboxyethylchitosan–modified silver nanoparticles for enhanced surgical suture performance

Antimicrobial surgical suture materials incorporating chloroxylenol-carboxyethylchitosan-modified silver nanoparticles (CECSX-AgNPs) were successfully prepared using the Layer-by-Layer (LbL) deposition technique. Chitosan (CS) was covalently affixed with chloroxylenol as hydrophobic functional groups (PCMX), yielding chloroxylenol-chitosan (CSX) and later hydrophilic acrylic acid onto the CSX skeleton, providing a novel water-soluble antimicrobial agent of chloroxylenol-carboxyethylchitosan (CECSX). 1H NMR confirmed the successful substitution of PCMX and acrylic acid onto CS, with %DSPCMX and %DSAA of 8.0 and 33.0, respectively. CECSX successfully stabilized AgNPs via the chemical reduction method, resulting in CECSX modified AgNPs. The colloidal solution exhibited a yellowish hue, spherical shape, monodispersity with an average particle size of 4.8 ± 2.4 nm, and a zeta potential value of −20.97 ± 0.03 mV. Minimum inhibitory concentration (MIC) values for CECSX-AgNPs against E. coli (ATCC25922), S. aureus (ATCC25923), and A. baumanii (ATCC19606) were determined as 25, 12.5, and 1.56 mg/L, respectively. Using the LbL deposition technique, CECSX-AgNPs were successfully deposited onto various suture materials including cotton, polyamide, and polypropylene. Remarkably, CECSX-AgNPs coated surgical sutures exhibited the highest bacterial reduction of 99.99 %. These findings underscore the efficacy of CECSX as a high-performance stabilizing agent for AgNPs production, providing outstanding antibacterial activity on diverse surgical suture materials and promoting the wound healing process.

Formulation of silver nanoparticles using Duabanga grandiflora leaf extract and evaluation of their versatile therapeutic applications.

The current research focused on the green synthesis of silver nanoparticles (AgNPs) using Duabanga grandiflora leaf extract. The green synthesis of AgNPs was confirmed by the surface plasmon resonance band at 453nm in a UV-Visible analysis. The formulated AgNPs had a diameter of around 99.72nm with a spherical shape. Fourier transform infrared (FTIR) spectrum revealed the bio-reducing potential of phytochemicals present in D. grandiflora, which fundamentally influenced the synthesis of AgNPs. Zeta potential, dynamic light scattering (DLS), scanning electron microscopic (SEM), energy-dispersive X-ray spectroscopic (EDX), X-ray diffraction (XRD), and transmission electron microscopic (TEM) analyses were executed to reveal the physicochemical attributes of the AgNPs. The AgNPs were further investigated for their antioxidant, antidiabetic, anticancer, and antibacterial potential. The DPPH free radical assay revealed the potential radical scavenging capacity (IC50 = 76.73μg/ml) of green synthesized AgNPs. α-Amylase inhibitory assay displayed significant inhibitory potential (IC50 = 162.11μg/ml) of this starch-breaking enzyme by AgNPs, revealing the antidiabetic potential of AgNPs. AgNPs exhibited potential cytotoxic activity (IC50 = 244.57µg/ml) against malignant human kidney cells. In addition, AgNPs showed outstanding antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains. Interestingly, AgNPs showed cytotoxic and antimicrobial activities at much higher concentrations than radical scavenging and α-amylase inhibitory concentrations. Thus, our finding elaborated the scope of green synthesized AgNPs for diverse therapeutic applications (dose-dependent) for further clinical translation.

Enhancing antibacterial activity and air filtration performance in electrospun hybrid air filters of chitosan (CS)/AgNPs/PVA/cellulose acetate: Effect of CS/AgNPs ratio

The increase in particulate matter (PM), especially PM2.5, has become a global threat to human health. To get rid of this severe pollutant, air filtration is forecasted as a promising, cost-effective, and effective method. This study utilized dual-spinneret electrospinning to fabricate the electrospun hybrid nanofibrous membranes (EHMs) of chitosan (CS)/silver nanoparticles (AgNPs)/polyvinyl alcohol (PVA)/cellulose acetate (CA). The effect of CS/AgNPs ratios was also investigated to obtain high-efficient air filtration membranes with outstanding antibacterial activity. Results disclosed that EHMs containing high AgNPs content improved the filtration performance and antibacterial properties while decreasing the wettability and tensile strength of EHM membranes. In addition, the EHM1 was found to be the most effective air filter membrane due to its high filtration efficiency of 99.78 % (PM2.5), low-pressure drop of 61.15 Pa, high-quality factor of 0.09 Pa−1, and enhanced inhibition zone of 100–141 %. Thus, this study suggests that the EHMs of CS/AgNPs/PVA/CA with a high AgNPs/CS ratio fabricated via a dual-electrospinning technique are expected to be a promising material choice for an air filter with efficient filtration performance and excellent antibacterial activity, resulting in a more sustainable and healthier future.

Antibacterial ZnO@CeO2 nanocrystals: Prospective material for control of foodborne pathogens.

Foodborne microbial infections are leading cause of many deadly illnesses. As a result, there is an anticipated need for the development of innovative packaging materials with effective antibacterial potential. This article describes preparation and characterization of innovative ZnO@CeO2 nanocrystals through a facile hydrothermal method, as well as their outstanding antibacterial properties. The ZnO@CeO2 nanocrystals used were prepared using precursors zinc acetate and cerium nitrate at 180°C. Various sophisticated physicochemical parameters were used to assess nanocrystals. The antibacterial activity was examined using minimum inhibitory concentration technique against four major foodborne pathogenic bacteria, namely Staphylococcus aureus (Gram positive), Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae (Gram negative) at four distinct concentrations (0-400 µg/mL). The in vitro cell compatibility test was done on fibroblasts. According to our findings, the lowest concentration of ZnO@CeO2 nanocrystals limiting development of tested strains is 100 µg/mL. Additionally, the results show that the combination of ZnO and CeO2 can be synergistic, resulting in ZnO@CeO2 nanocrystals with enhanced antibacterial activity. To summarize, unique ZnO@CeO2 nanocrystals with a high surface-to-volume ratio with outstanding antibacterial activity and no harmful impact to mouse fibroblasts were shaped. The ZnO@CeO2 can be utilized to competently suppress microbial growth spoiling the food and could be utilized as economical and efficient future packaging material for food industries.

An in situ dressing material containing a multi‐armed antibiotic for healing irregular wounds

AbstractAcute and infected wounds resulting from accidents, battlefield trauma, or surgical interventions have become a global healthcare burden due to the complex bacterial infection environment. However, conventional gauze dressings present insufficient contact with irregular wounds and lack antibacterial activity against multi‐drug‐resistant bacteria. In this study, we develop in situ nanofibrous dressings tailored to fit wounds of various shapes and sizes while providing nanoscale comfort and excellent antibacterial properties. Our approach involves the fabrication of these dressings using a handheld electrospinning device that allows for the direct deposition of nanofiber dressings onto specific irregular wound sites, resulting in perfect conformal wound closure without any mismatch in 2 min. The nanofibrous dressings are loaded with multi‐armed antibiotics that exhibit outstanding antibacterial activity against Staphylococcus aureus (S. aureus) and methicillin‐resistant S. aureus. Compared to conventional vancomycin, this in situ nanofibrous dressing shows great antibacterial performance against up to 98% of multi‐drug‐resistant bacteria. In vitro and in vivo experiments demonstrate the ability of in situ nanofibrous dressings to prevent multi‐drug‐resistant bacterial infection, greatly alleviate inflammation, and promote wound healing. Our findings highlight the potential of these personalized nanofibrous dressings for clinical applications, including emergency, accident, and surgical healthcare treatment.

3D Printing Drug-Free Scaffold with Triple-Effect Combination Induced by Copper-Doped Layered Double Hydroxides for the Treatment of Bone Defects.

Tissue-engineered poly(l-lactide) (PLLA) scaffolds have been widely used to treat bone defects; however, poor biological activities have always been key challenges for its further application. To address this issue, introducing bioactive drugs or factors is the most commonly used method, but there are often many problems such as high cost, uncontrollable and monotonous drug activity, and poor bioavailability. Here, a drug-free 3D printing PLLA scaffold with a triple-effect combination induced by surface-modified copper-doped layered double hydroxides (Cu-LDHs) is proposed. In the early stage of scaffold implantation, Cu-LDHs exert a photothermal therapy (PTT) effect to generate high temperature to effectively prevent bacterial infection. In the later stage, Cu-LDHs can further have a mild hyperthermia (MHT) effect to stimulate angiogenesis and osteogenic differentiation, demonstrating excellent vascularization and osteogenic activity. More importantly, with the degradation of Cu-LDHs, the released Cu2+ and Mg2+ provide an ion microenvironment effect and further synergize with the MHT effect to stimulate angiogenesis and osteogenic differentiation, thus more effectively promoting the healing of bone tissue. This triple-effect combined scaffold exhibits outstanding antibacterial, osteogenic, and angiogenic activities, as well as the advantages of low cost, convenient procedure, and long-term efficacy, and is expected to provide a promising strategy for clinical repair of bone defects.

Chemical profiling and inhibitory effects of selected South African plants against phytopathogenic bacteria and fungi of tomato

Soilborne pathogens are economically important, causing great losses in agricultural production globally. The high cost and toxicity of antibiotics, coupled with the development of drug-resistant bacteria, has awakened interest in finding alternative methods of plant-pathogen control. This study aimed to screen extracts of selected plants against phytopathogenic bacteria and fungi that infect tomatoes, and to profile their chemical constituents. The antimicrobial activity of acetone, water and dichloromethane: methanol (DCM/MeOH = 1:1) extracts from leaves of ten plants was examined against five phytopathogenic bacterial strains and one fungal strain using a serial microplate dilution method to determine the minimal inhibitory concentration (MIC) values. Gas chromatography-mass spectrometry (GC–MS) was used for profiling constituents in the acetone and DCM/MeOH extracts. The MIC values indicated weak antibacterial activity of all the water extracts against tested bacterial strains. Acetone and DCM/MeOH extracts of Leucosidea sericea and Searsia lancea had very good to outstanding antibacterial activity against most of the tested bacteria with MIC values ranging between 19.5 and 78 µg/mL. All extracts were not active against Fusarium spp. except for the acetone extract of Cotyledon orbiculata and the water extract of Leonotis leonurus which inhibited the growth of F. oxysporum with MIC = 39 and 97.5 µg/mL after 24 h, with further incubation resulting in MICs of 156 and 469 µg/mL respectively. The GC–MS analysis of the acetone and DCM/MeOH extracts indicated the major peaks of 9-octadecenamide, (Z)-, octadecanoic acid and dodecanamide which were present in almost all the extracts. The 9-octadecenamide was found to be the most highly concentrated compound in most extracts. Leucosidea sericea and S. lancea, therefore, contain bioactive compounds that may be used as broad-spectrum antimicrobials against phytopathogenic bacteria and fungi.

Antibacterial durability of L-methionine modified cotton fabrics functionalized with ZnO nanoparticles

Cotton fabric based textiles utilizing metal oxide nanoparticles (NPs), offer potential options for reducing spreading of infection by bacteria due to their excellent antimicrobial properties, which depend on the nanoparticle's structure and morphology, as well as the fiber functionalization process. In this work, a simple padding and rolling technique for preparing antibacterial cotton fabrics by functionalizing their surface with nanostructured ZnO is demonstrated. L-methionine amino acid is utilized as a binding reagent due to its low toxicity to mammalian cells, biocompatibility with living tissues, and the presence of amine and carboxylic groups, which enhance its coordination capacity to improve ZnO adhesion. Zn(NO3)2·3H2O was precipitated as Zn(OH)2(s) using an alkali mixture of (NaOH+NaBH4), which was then converted into ZnO NPs up on heat treatment on the surface of modified cotton (LCt). Fourier transform infrared spectroscopy (ATR-FTIR) was utilized to confirm the chemical alteration of the fabrics by L-methionine. X-ray diffraction (XRD) investigations confirmed the crystalline structure, purity, and average crystallite size of the ZnO NPs (15.72 nm). X-ray photoelectron spectroscopy (XPS) tests revealed that the NPs were successfully coordinately bonded to the textiles. HR-SEM and energy-dispersive X-ray (EDS) mapping demonstrated that NPs were well-covered on the fabric fibers. The thermal degradation behavior of the modified and functionalized cotton was examined by thermal gravimetric analysis (TGA). The functionalized fabric shown outstanding antibacterial activity against gram-negative bacteria, E. coli and P. aeruginosa, as well as gram-positive bacteria S. aurous and S. pyogenes, with washing durability of up 50 wash cycles. After 50 wash cycles, approximately 88 % of the Zn was retained. This indicated a strong bond between the fabrics. Furthermore, the change has little effect on cotton qualities such as vapor permeability, water absorption, and water transport.

Constructing a Photothermal and Quaternary Ammonium Cation Bactericidal Platform onto SEBS for Synergistic Therapy.

Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) with eminent elasticity, thermoplastic ability, and biological stability has aroused great interest in the medical area. However, bacteria can easily adhere to the hydrophobic SEBS surface to cause medical device-related infections. In this work, SEBS is modified to prepare the SEBS-polydopamine (PDA)-poly(lysine) quaternary ammonium derivative (PLQ) antibacterial surface by PDA deposition and surface grafting techniques to solve bacterial infections. PDA is used as an intermediate layer and presents an excellent photothermal effect. The grafted polymer PLQ has antimicrobial quaternary ammonium cation groups, which plays synergistic bactericidal therapy with PDA. The SEBS-PDA-PLQ surface almost totally suppresses the growth of bacteria with a surface bacterial survival rate of 0.05% under laser irradiation. The outstanding antibacterial activity of the SEBS-PDA-PLQ surface is attributed to the synergistic effects of the photothermal performance of PDA and quaternary ammonium cationic functional groups of PLQ. In addition, the membrane SEBS-PDA-PLQ shows good hydrophilicity, antiprotein adsorption ability, chemical stability, and biocompatibility. This antibiotic-free antimicrobial approach has great potential for practical application in solving infections associated with medical devices.

Cellulose-reinforced poly(Ionic Liquids) composite hydrogel for infected wounds therapy and real-time reliable bioelectronic

With the increasing utilization of therapeutic materials in wound care and skin bioelectronics, there is growing requirements for multifunctional hydrogels for personal therapy and health management. However, the limited functionality, mechanical incompatibility, and impracticality of traditional dressings and skin bioelectronics greatly restrict their widespread use in clinical settings. Herein, we fabricate a cellulose nanofibers (CNFs)-reinforced poly(Ionic Liquids) (PILs) composite hydrogel (PACxVy) which can be used as infected wound therapy and real-time reliable bioelectronic. The hydrogel showed an orderly interconnected cellular architecture with excellent stretchability, outstanding elasticity and low hysteresis. As a wound dressing, the hydrogel could provide the adhesion to seal wounds, biocompatibility and outstanding antibacterial activity, enabling the wound dressing to effectively inhibit bacterial growth and accelerate infected wound healing. ILs enables the hydrogel to have high conductivity, outstanding sensing performance and impressive temperature response. Therefore, the hydrogel may also work as novel flexible bioelectronics, which could accurately capture motion signals ranging from large strain to minute physiological signal, such as body movement, heart rate, pulse, and body temperature. Notably, a dual-channel remote clinical alarm system was fabricated by combining the hydrogel with tailor-made single-chip to wireless real-time monitoring of finger joint movement and temperature changes, which could establish a communication channel between patient and wounded and provide effective medical intervention timely. This line of research work sheds light on the hydrogel has significant implications for improving personal therapy and health management.

Biodegradable nanocomposites prepared from poly(butylene adipate terephthalate) and silver nanoparticles for applications as disposable medical equipments

AbstractSilver nanoparticles (AgNPs) were prepared using polyvinylpyrrolidone (PVP) as reducing and stabilizing agent. AgNPs were then embedded in a biodegradable poly(butylene adipate terephthalate) (PBAT) matrix by solution casting. The resulted PBAT/AgNPs nanocomposite films were characterized using various analytical techniques such as scanning electron microscopy (SEM), colorimeter, Ultraviolet–visible (UV–vis) spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), thermogravimetric analysis (TGA), mechanical tests and water vapor permeability measurements. The composite films appeared smooth on surface with some agglomeration of AgNPs. The addition of AgNPs led to color changes, and strongly improved the thermal stability, UV barrier performance, mechanical properties and water vapor barrier performance of composite films. Importantly, PBAT/AgNPs films present outstanding antibacterial activity against gram‐positive bacteria (Escherichia coli) and gram‐negative bacteria (Staphylococcus aureus). Moreover, composite films exhibit good stability under accelerated aging conditions and during high‐pressure sterilization. Therefore, biodegradable PBAT/AgNPs nanocomposite materials could present great potential for applications as disposable medical equipments.

Synergistic enhancement of external electrical energy in PM filtration with Cu-HHTP@CuO nanowire arrays coated copper mesh

Developing multifunctional purification systems that combine air filtration and antibacterial functionality is a challenging task. However, in designing air filtration materials, achieving a balance between filtration efficiency and pressure drop remains a significant challenge. In this study, we developed a novel filtration material composed of hierarchically 3D Cu-HHTP nanowiskers coated CuO nanowires that were grown in-situ on a copper mesh. Benefitted from the intrinsically electrical conductivity of Cu-HHTP, we combined the composite material with external electrical energy for air filtration. By applying lower electric potential directly (voltage of 5 V), the 3D conductive mesh filter exhibited excellent performances in terms of the PM2.5 removal efficiency (∼99.7%), pressure drop (∼32 Pa at 2 cm s -1), and quality factor (0.187 at 2 cm s -1). Furthermore, after ten cycles of filtration and cleaning, the material maintained a high PM removal rate. In addition to its excellent filtration performance, the composite metal mesh also exhibited outstanding antibacterial activity against both E. coli and S. aureus. The electro-mechanical stability and recyclability of the composite filter make it a cost-effective and environmentally friendly solution for air purification, with promising potential for improving air quality.