Outstanding Antibacterial Properties Research Articles

Multibiofunctional Self-healing Adhesive Injectable Nanocomposite Polysaccharide Hydrogel.

Injectable hydrogels with good antimicrobial and antioxidant properties, self-healing characteristics, suitable mechanical properties, and therapeutic effects have great practical significance for developing treatments for pressing healthcare challenges. Herein, we have designed a novel, self-healing injectable hydrogel composite incorporating cross-linked biofunctional nanomaterials by mixing alginate aldehyde (Ox-Alg), quaternized chitosan (QCS), adipic acid dihydrazide (ADH), and copper oxide nanosheets surface functionalized with folic acid as the bioligand (F-CuO). Gelation was achieved under physiological conditions via the dynamic Schiff base cross-linking mechanism. The developed nanocomposite injectable hydrogel demonstrated the fast self-healing ability essential to bear deformation and outstanding antibacterial properties along with ROS scavenging ability. Furthermore, the optimized formulation of our F-CuO-embedded injectable hydrogel exhibited excellent cytocompatibility, blood compatibility, and in vitro wound healing performance. Taken together, the F-CuO nanosheet cross-linked injectable hydrogel composite presented herein offers a promising candidate biomaterial with multifunctional properties to develop solutions for addressing clinical challenges.

Fabrication of Poly(ionic liquid) Hydrogels Incorporating Liquid Metal Microgels for Enhanced Synergistic Antifouling Applications.

Hydrogels are ideal for antifouling materials due to their high hydrophilicity and low adhesion properties. Herein, poly(ionic liquid) hydrogels integrated with zwitterionic copolymer-functionalized gallium-based liquid metal (PMPC-GLM) microgels were successfully prepared by a one-pot reaction. Poly(ionic liquid) hydrogels (IL-Gel) were obtained by chemical cross-linking the copolymer of ionic liquid, acrylic acid, and acrylamide, and the introduction of ionic liquid (IL) significantly increased the cross-linking density; this approach consequently enhanced the mechanical and antiswelling properties of the hydrogels. The swelling ratio of IL-Gel decreased eight times compared to the original hydrogels. PMPC-GLM microgels were prepared through grafting the zwitterionic polymer PMPC onto the GLM nanodroplet surface, which exhibited efficient antifouling performance attributed to the bactericidal effect of Ga3+ and the antibacterial effect of the zwitterionic polymer layer PMPC. Based on the synergistic effect of PMPC-GLM microgels and IL, the composite hydrogels PMPC-GLM@IL-Gel not only exhibited excellent mechanical and antiswelling properties but also showed outstanding antibacterial and antifouling properties. Consequently, PMPC-GLM@IL-Gel hydrogels achieved inhibition rates of over 90% against bacteria and more than 85% against microalgae.

UPLC-qTOF-MS phytochemical profile of Commiphora gileadensis leaf extract via integrated ultrasonic-microwave-assisted technique and synthesis of silver nanoparticles for enhanced antibacterial properties

The utilization of metallic nanoparticles in bio-nanofabrication holds significant potential in the field of applied research. The current study applied and compared integrated ultrasonic-microwave-assisted extraction (US/MICE), ultrasonic extraction (USE), microwave-assisted extraction (MICE), and maceration (MAE) to extract total phenolic content (TPC). In addition, the study examined the antioxidant activity of Commiphora gileadensis (Cg) leaf. The results demonstrated that the TPC of US/MICE exhibited the maximum value at 59.34 ± 0.007 mg GAE/g DM. Furthermore, at a concentration of 10 μg/mL, TPC displayed a significant scavenging effect on DPPH (56.69 %), with an EC50 (6.48 μg/mL). Comprehensive metabolite profiling of the extract using UPLC-qTOF-MS/MS was performed to identify active agents. A total of 64 chromatographic peaks were found, out of which 60 were annotated. The most prevalent classes of metabolites found were polyphenols (including flavonoids and lignans), organic compounds and their derivatives, amides and amines, terpenes, and fatty acid derivatives. Transmission electron microscopy (TEM) revealed the aggregate size of the synthesized nanoparticles and the spherical shape of C. gileadensis-mediated silver nanoparticles (Cg-AgNPs). The nanoparticles had a particle size ranging from 7.7 to 42.9 nm. The Cg-AgNPs exhibited more inhibition zones against S. aureus and E. coli. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Cg-extract, AgNPs, and Cg-AgNPs were also tested. This study demonstrated the feasibility of using combined ultrasonic-microwave-assisted extraction to separate and extract chemicals from C. gileadensis on a large scale. These compounds have potential use in the pharmaceutical industry. Combining antibacterial and biocompatible properties in materials is vital for designing new materials for biomedical applications. Additionally, the results showed that the biocompatibility of the Ag-NPs using C. gileadensis extracts demonstrated outstanding antibacterial properties.

Highly Conjugated Nanozyme with Non Coordination Saturation for Cascaded Enhanced POD Reaction Driving Antibacterial Therapy

AbstractThe misuse of antibiotics leads to emergence of drug‐resistant bacteria. Developing artificial nanozymes with high stability and excellent catalytic performance is desirable to substitute for antibiotics, but still remains huge challenge. Herein, the study reports a new strategy for cascaded enhanced peroxidase (POD) reaction driving antibacterial therapy via constructing 2D conjugated metal‐organic frameworks (MOFs) with non coordination saturation as nanozyme. It is demonstrated that the non coordination saturation Cu atom promotes the adsorption of H2O2, followed by the Cu‐HHTP MOFs with high conjugated structure can enhance the photogenerated electron transfer for ·OH generation in POD reaction. The sequential enhancement of substrate adsorption and decomposition endows the as‐made Cu‐HHTP MOFs with outstanding antibacterial property of >99.9999% elimination with a concentration only 1/133 that of traditional nanozyme. In addition, the study also certifies its excellent in vivo antimicrobial activity and biocompatibility, indicating the therapeutic potential for infections by drug‐resistant bacteria.

Silk fibroin sponge impregnated with fish bone collagen: A promising wound healing scaffold and skin tissue regeneration.

In the present study, porous silk fibroin sponges (SFS) were prepared using silk fibroin (SF), fish bone collagen (FBC), and olive oil (OO). The study investigates the potential use of using this sponge as skin tissue regeneration. The sponge was characterized for its physicochemical, mechanical, antimicrobial, and drug release properties. An in vitro study was carried out using human keratinocyte cell line (HaCaT). Biodegradation study using enzymatic method was carried out. The results showed that the mechanical properties such as tensile strength (23.40 ± 0.05 MPa), elongation at break (14.25 ± 0.02%), and water absorption (30.23 ± 0.01%) of the SFS were excellent, indicating promising performance. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays proved the biocompatible nature of the SFS. The SFS exhibited outstanding antibacterial properties against E. coli (4.72 ± 0.05 mm) and S. aureus (4.98 ± 0.07 mm). The developed SFS promote a promising solution for skin tissue regeneration and wound dressing.

Geopolymers functionalised by antibacterial zeolite against biocorrosion

Aluminosilicate geopolymer with remarkable chemical and biological resistance is a promising material solution to the persistent challenge of microbial induced concrete corrosion (MICC) in sewers. In this work, novel Sor-zeolite, assembled by using microporous 13X zeolite as a host of antimicrobial ion sorbate, is incorporated into fly ash-slag geopolymer to form bio-resistant materials with long-lasting efficacy and densified microstructure. The inclusion of pure zeolite and Sor-zeolite increase the strength and refine the pore structure of geopolymer pastes owing to the seeding nuclei effects during the geopolymerisation process. The enhanced dissolution of FA and slag by the seeding effects of pure zeolite and Sor-zeolite, accelerates and enriches the precipitation of geopolymeric gels, mainly a mixture of K-A-S-H and C-A-S-H (abbreviated as K-(C)-A-S-H). The Sor-zeolite-functionalised geopolymer possesses outstanding antibacterial properties against sulphur oxidising bacteria Acidithiobacillus thiooxidans, inhibiting biofilm formation on the surface and reducing corrosion depth. The main biodegradation products of geopolymers are gypsum and silica-rich gels, resulted from decalcification and dealumination of Si–O–Al and Ca–O bonds in K-(C)-A-S-H.

Antibacterial and anti-inflammatory Bi-functional carbon dots hydrogel dressing for robust promotion of wound healing

The abuse of antibiotics leading to bacterial resistance has emerged as a significant impediment to wound healing. Consequently, this study developed antibacterial and anti-inflammatory bi-functional carbon dots (AAB-CDs) as the primary active material for the preparation of hydrogel wound dressings, aiming to promote wound healing. The synthesized AAB-CDs exhibited ultra-small size (2.3 nm), abundant surface functional groups, high Zeta potential (30.9 mV), and excellent biocompatibility. The positively charged AAB-CDs with outstanding antibacterial properties, mitigating the risk of bacterial resistance, while the abundant surface functional groups imparted stable antioxidant performance for sustained wound anti-inflammatory effects. Moreover, in vitro experiments demonstrated that the hydrogel dressings exhibited remarkable antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and significantly promoted the proliferation of L929 fibroblasts. In vivo experiments further substantiated the feasibility of the hydrogel dressings in promoting wound healing and histological analysis revealed the biological mechanisms underlying the promotion of wound healing. In conclusion, AAB-CDs with robust antibacterial and anti-inflammatory properties hold tremendous potential for promoting wound healing, providing practical insights for the biological application of CDs.

A natural inhibitor of diapophytoene desaturase attenuates methicillin-resistant Staphylococcus aureus (MRSA) pathogenicity and overcomes drug-resistance.

At present, the inhibition of staphyloxanthin biosynthesis has emerged as a prominent strategy in combating methicillin-resistant Staphylococcus aureus (MRSA) infection. Nonetheless, there remains a limited understanding regarding the bio-structural characteristics of staphyloxanthin biosynthetic enzymes, as well as the molecular mechanisms underlying the interaction between inhibitors and proteins. Furthermore, the functional scope of these inhibitors is relatively narrow. In this study, we address these limitations by harnessing the power of deep learning techniques to construct the 3D structure of diapophytoene desaturase (CrtN). We perform efficient virtual screening and unveil alnustone as a potent inhibitor of CrtN. Further investigations employing molecular modelling, site-directed mutagenesis and biolayer interferometry (BLI) confirmed that alnustone binds to the catalytic active site of CrtN. Transcriptomic analysis reveals that alnustone significantly down-regulates genes associated with staphyloxanthin, histidine and peptidoglycan biosynthesis. Under the effects of alnustone, MRSA strains exhibit enhanced sensitivity to various antibiotics and the host immune system, accompanied by increased cell membrane permeability. In a mouse model of systemic MRSA infection, the combination of alnustone and antibiotics exhibited a significant therapeutic effect, leading to reduced bacterial colony counts and attenuated pathological damage. Alnustone, as a natural inhibitor targeting CrtN, exhibits outstanding antibacterial properties that are single-targeted yet multifunctional. This finding provides a novel strategy and theoretical basis for the development of drugs targeting staphyloxanthin producing bacteria.

Gold nanoparticles exhibit anti-osteoarthritic effects via modulating interaction of the “microbiota-gut-joint” axis

Osteoarthritis (OA) is a common degenerative joint disease that can cause severe pain, motor dysfunction, and even disability. A growing body of research indicates that gut microbiota and their associated metabolites are key players in maintaining bone health and in the progression of OA. Short-chain fatty acids (SCFAs) are a series of active metabolites that widely participate in bone homeostasis. Gold nanoparticles (GNPs) with outstanding anti-bacterial and anti-inflammatory properties, have been demonstrated to ameliorate excessive bone loss during the progression of osteoporosis (OP) and rheumatoid arthritis (RA). However, the protective effects of GNPs on OA progression are not clear. Here, we observed that GNPs significantly alleviated anterior cruciate ligament transection (ACLT)-induced OA in a gut microbiota-dependent manner. 16S rDNA gene sequencing showed that GNPs changed gut microbial diversity and structure, which manifested as an increase in the abundance of Akkermansia and Lactobacillus. Additionally, GNPs increased levels of SCFAs (such as butyric acid), which could have improved bone destruction by reducing the inflammatory response. Notably, GNPs modulated the dynamic balance of M1/M2 macrophages, and increased the serum levels of anti-inflammatory cytokines such as IL-10. To sum up, our study indicated that GNPs exhibited anti-osteoarthritis effects via modulating the interaction of “microbiota-gut-joint” axis, which might provide promising therapeutic strategies for OA.

A Covalent‐Metal Hybrid‐Link Organic Framework Spray for Portable and Instant Therapy of Deep‐Degree Burn

AbstractDeep burns lead to extensive damage to the dermal layer, necessitating a longer treatment duration than typical skin injuries. Such burn wounds become more susceptible to drug‐resistant bacterial infections, thereby complicating and prolonging the therapeutic process. In this study, a unique spray composed of covalent metal hybrid‐linked organic frameworks (HLOF) material is developed that effectively eradicates methicillin‐resistant Staphylococcus aureus (MRSA) within 20 min by disrupting MRSA's surface electrons, destroying its cell membrane structure, and ultimately causing its demise with an impressive antibacterial rate of 96.7%. This HLOF material exhibited exceptional biological activity and stability. During the wound recovery procedure, HLOF promoted the expression of Vascular endothelial growthfactor(VEGF) to stimulate angiogenesis while inhibiting the proinflammatory factor Tumor necrosis factor alpha (TNF‐α) expression to eliminate inflammation and further enhance wound repair. This study presents an innovative approach for achieving outstanding antibacterial properties and improved biocompatibility through modifications made to common metal organic frameworks (MOFs), thus expanding their potential applications.

Research Progress on Benzimidazole Fungicides: A Review.

Benzimidazole fungicides are a class of highly effective, low-toxicity, systemic broad-spectrum fungicides developed in the 1960s and 1970s, based on the fungicidal activity of the benzimidazole ring structure. They exhibit biological activities including anticancer, antibacterial, and antiparasitic effects. Due to their particularly outstanding antibacterial properties, they are widely used in agriculture to prevent and control various plant diseases caused by fungi. The main products of benzimidazole fungicides include benomyl, carbendazim, thiabendazole, albendazole, thiophanate, thiophanate-methyl, fuberidazole, methyl (1-{[(5-cyanopentyl)amino]carbonyl}-1H-benzimidazol-2-yl) carbamate, and carbendazim salicylate. This article mainly reviews the physicochemical properties, toxicological properties, disease control efficacy, and pesticide residue and detection technologies of the aforementioned nine benzimidazole fungicides and their main metabolite (2-aminobenzimidazole). On this basis, a brief outlook on the future research directions of benzimidazole fungicides is presented.

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.

Electrophoretic deposition of photothermal responsive antibacterial coatings on titanium with controlled release of silver ions

Burst release of antibacterial agents generated by the surface antibacterial modification of Ti implants frequently results in a reduction in their biocompatibility and substantial toxic side effects. In this study, core-shelled nanoparticles namely AgNR@MSN, were synthesized successfully by mesoporous silica shell in-situ encapsulated Ag nanorods, and then co-deposited with chitosan to form a AgNR@MSN-chitosan composite coating on Ti substrate by electrophoretic deposition. The developed composite coating, due to the presence of AgNR, presented excellent photothermal effect under the irradiation of an 808 nm near-infrared laser, leading to both rapid increase of local temperature and triggered release of Ag ions for bacterial-killing effect against both E. coli and S. aureus. The addition of AgNR@MSN also improved the wettability of the coating and the MSN shell with mesoporous tunnels could barrier the contact and release rate of Ag to improve the biocompatibility. The developed photothermal responsive coating could be considered as a promising platform for achieving controlled release of Ag ions with outstanding antibacterial and biocompatible properties.

A Sandwich Structure Ag/MgFe2O4-Deposited Surface Carbonized Wood for Integrated Solar Steam Generation and Photoreduction of Cr(VI).

The severe deterioration of the marine ecosystem significantly negatively impacts the performance of solar-driven steam generation (SSG) and the quality of the obtained freshwater. Herein, a bifunctional Ag/MgFe2O4@SCW reactor with a sandwich structure is designed for efficient SSG and Cr(VI) reduction, which is constructed via in situ deposit Ag nanoparticles (NPs) and MgFe2O4 onto surface carbonized wood (SCW). Owing to the advanced sandwich structure and strong interfacial interactions between each component, an ultra-high evaporation rate of 1.55kg m-2 h-1 and the efficiency of 88.6% are achieved using Ag/MgFe2O4@SCW under 1 sun. The system exhibits the long-term evaporation performance in the simulated sewage and strong acid/base solutions along with water-harvesting capacity in outdoor solar desalination. The quality of distilled water after desalination of actual seawater and NaCl solutions with different concentrations meets the WHO-recommended drinkable water standards. Furthermore, Ag/MgFe2O4@SCW shows outstanding antibacterial property, self-desalting capacity, as well as reusability and structure stability. Most importantly, the fast carrier separation endows Ag/MgFe2O4@SCW with superior photocatalytic activity and Cr(VI) photoreduction of up to 96.1% after 180min of illumination. The bifunctional Ag/MgFe2O4@SCW reactor provides an advanced synergistic mechanism for improving SSG and photocatalytic performance, while being promising for solar-powered production of clean water.

Antibacterial properties of enzymatically treated PET fibers functionalized by nitric oxide

At present, microbes have enormous potential to become a major global public health issue. For example, Escherichia coli is the prominent cause of cholecystitis, urinary tract infections, and other infections. Due to its outstanding antibacterial properties, nitric oxide (NO) is essential for biological processes. Additionally, enzymatic hydrolysis using polyethylene terephthalate hydrolase (PETase) is one of the promising methods for PET upcycling. First, recombinant PETase was used to enzymatically treat waste PET fibers, and polyethylenimine (PEI) was added as a secondary amine donor. Subsequently, the aminated PET fiber was inserted into a reactor charged with NO gas (10 atm, 3 days) to obtain N-diazeniumdiolate (NONOate) products that can inhibit bacteria growth. In this study, the first strategy for antibacterial applications by NO-releasing PETase-hydrolyzed PET fibers was demonstrated. NO-conjugated PET fibers were successfully prepared which exhibits a continuous NO release profile over 12 h. The surface properties of functionalized PET fibers were successfully confirmed by fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and Griess assay. The antibacterial test indicated a reduction of Escherichia coli by 90.2% and Staphylococcus aureus by 71.1% after exposure to the functionalized material. Therefore, this novel antibacterial agent may offer great potential applications in the medical field.

Injectable hydrogels activated with copper sulfide nanoparticles for enhancing spatiotemporal sterilization and osteogenesis in periodontal therapy.

Developing biomaterials capable of promoting bone regeneration in bacteria-infected sites is of utmost urgency for periodontal disease therapies. Here we produce a hybrid hydrogel by integrating CuS nanoparticles (CuSNPs), which could kill bacteria through photothermal therapy (PTT) triggered by a near infrared (NIR) light, and a gelatin methacryloyl (GelMA) hydrogel, which is injectable and biocompatible. Specifically, CuSNPs were precipitated by chitosan (CS) firstly, then grafted with methacrylic anhydride (MA) to form CuSNP@CS-MA, which was photo-crosslinked with GelMA to synthesize hybrid hydrogels (GelMA/CuSNP). The hybrid hydrogels exhibited a broad-spectrum antibacterial property that could be spatiotemprorally manipulated through applying a NIR light. Their mechanical properties were adjustable by controlling the concentration of CuSNPs, enabling the hydrogels to become more adapted to the oral diseases. Meanwhile, the hybrid hydrogels showed good cytocompatibility in vitro and improved hemostasis in vivo. Moreover, they accelerated alveolar osteogenesis and vascular genesis, successfully treating periodontis in four weeks in a rat model. GelMA/CuSNP hydrogels showed a broad-spectrum sterilization ability via PTT in vitro and outstanding antibacterial property in vivo, suggesting that the hybrid hydrogels could function in the challenging, bacteria-rich, oral environment. Such injectable hybrid hydrogels, capable of achieving both facilitated osteogenesis and NIR-inducible sterilization, represent a new biomaterial for treating periodontitis.

Injectable, thermo-sensitive and self-adhesive supramolecular hydrogels built from binary herbal small molecules towards reusable antibacterial coatings.

Herbal hydrogels as a new class of sustainable functional materials have attracted extensive attention. However, the development of herbal hydrogels is significantly hindered due to their poor hydrogel performances and the lack of universal preparation methods. In this study, four herbal hydrogels composed of phytochemical polyphenols and stevioside compounds are prepared through a facile heating-cooling process, where multiple hydrogen bonding interactions between two monomers provide the main driving force for gelation. These herbal hydrogels exhibit thermo-sensitivity and good reversibility (25-90 °C), robust adhesion behaviours on hydrophilic and hydrophobic surfaces (maximum adhesion strength of 591.7 kPa), and outstanding antibacterial properties (100% bacteriostatic ratio). Profiting from these intriguing characteristics, they are demonstrated to show great potential as natural antibacterial coatings by depositing thin hydrogel layers onto diverse substrates. More importantly, the hydrogel coatings could be easily recycled by thermal regelation and reused at least 5 times. This work proposes a simple and universal strategy for preparing functional hydrogels based on binary herbal small molecules, which also sheds light on the development of reusable hydrogel coatings.

Regulation of band gap and localized surface plasmon resonance by loading Au nanorods on violet phosphene nanosheets for photodynamic/photothermal synergistic anti-infective therapy.

In the face of the serious threat to human health and the economic burden caused by bacterial antibiotic resistance, 2D phosphorus nanomaterials have been widely used as antibacterial agents. Violet phosphorus nanosheets (VPNSs) are an exciting bandgap-adjustable 2D nanomaterial due to their good physicochemical properties, yet the study of VPNS-based antibiotics is still in its infancy. Here, a composite of gold nanorods (AuNRs) loaded onto VPNS platforms (VPNS/AuNR) is constructed to maximize the potential of VPNSs for antimicrobial applications. The loading with AuNRs not only enhances the photothermal performance via a localized surface plasmon resonance (LSPR) effect, but also enhances the light absorption capacity due to the narrowing of the band gap of the VPNSs, thus increasing the ROS generation capacity. The results demonstrate that VPNS/AuNR exhibits outstanding antibacterial properties and good biocompatibility. Attractively, VPNS/AuNR is then extensively tested for treating skin wound infections, suggesting promising in vivo antibacterial and wound-healing features. Our findings may open a novel direction to develop a versatile VPNS-based treatment platform, which can significantly boost the progress of VPNS exploration.

Preparation of polyethersulfone ultrafiltration membrane coated natural additives toward antifouling and antimicrobial agents for surface water filtration

Chitosan (CS) and polyphenon 60 from green tea (PGT) as natural additives were used in the preparation of antifouling and antibacterial polyethersulfone (PES) ultrafiltration membranes via the surface coating method. The effect of additive coating on fouling resistance and antibacterial properties were evaluated. The membrane characterizations were carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and surface hydrophilicity by contact angle. The results showed that the optimized modified membrane (1 wt% CS/3 wt% PGT-coated PES, denoted as CS1PGT3) demonstrated better hydrophilicity than the pristine PES membrane. In addition, the CS1PGT3 membrane exhibited high BSA rejection (99.99%), relatively high flux recovery (78.78%), and the highest water flux (46.83 L/m2.h) among all modified PES membranes. After the CS1PGT3 membrane was immersed in different soaking solutions (i.e., acid, alkaline, and neutral) for 21 days, the stability of CS and PGT groups on the PES membrane was also confirmed. Moreover, during examination using surface water filtration, the removal rates of chemical oxygen demand, turbidity, and aromatic compounds were increased from 64.30%, 34.23%, and 62.78% to 88.22%, 64.18%, and 84.21%, respectively. The largest inhibition zone diameter (7.83 mm of E. coli) and highest antibacterial efficiency (99% of E. coli) were achieved, suggesting the outstanding antibacterial properties of the optimized modified membrane. Thus, the incorporation of CS/PGT into PES membrane via the surface coating showed promising method to enhance antifouling and antibacterial properties.

Cellulose nanofibers embedded chitosan/tannin hydrogel with high antibacterial activity and hemostatic ability for drug-resistant bacterial infected wound healing

Millions of patients annually suffer life-threatening illnesses caused by bacterial infections of skin wounds. However, the treatment of wounds infected with bacteria is a thorny issue in clinical medicine, especially with drug-resistant bacteria infections. Therefore, there is an increasing interest in developing wound dressings that can efficiently fight against drug-resistant bacterial infections and promote wound healing. In this work, an anti-drug-resistant bacterial chitosan/cellulose nanofiber/tannic acid (CS/CNF/TA) hydrogel with excellent wound management ability was developed by electrospinning and fiber breakage-recombination. The hydrogel exhibited an outstanding antibacterial property exceeding 99.9 %, even for drug-resistant bacteria. This hydrogel could adhere to the tissue surface due to its abundant catechol groups, which avoided the shedding of hydrogel during the movement. Besides, it exhibited extraordinary hemostatic ability during the bleeding phase of the wound and then regulated the wound microenvironment by absorbing water and moisturizing. Moreover, the CS/CNF/TA also promoted the regrowth of vessels and follicles, accelerating the healing of infected wound tissue, with a healing rate exceeding 95 % within a 14-day timeframe. Therefore, the CS/CNF/TA hydrogel opens a new approach for the healing of drug-resistant bacterial infected wounds.