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In this study, a kind of nanocomposite film was fabricated via combining silk fibroin, polyvinyl alcohol (SF/PVA) and AgNP/polydopamine-modified Montmorillonite (AgNP/PDA-Mt). The structural characteristics and properties of the SF/PVA/AgNP/PDA-Mt nanocomposites films were identified using X-ray diffraction (XRD), Thermal gravimetric analyzer (TGA), Fourier transform infrared spectroscopy (FTIR), EDS-mapping analyses and Scanning electron microscope (SEM). The results indicated enhanced thermal performance of SF/PVA/AgNP/PDA-Mt nanocomposites with increased AgNP/PDA-Mt weight. The nanocomposite film exhibited excellent antibacterial activity against E. coli and S. aureus. The 2 % SF/PVA/AgNP/PDA-Mt film showed the highest zone of inhibition with an average inhibition circle diameter of 26.1 mm against E. coli and 20.61 mm against S. aureus. Cytotoxicity test results indicated that the nanocomposites films were biocompatible with L929 cells with a 100 % survival rate, which can be considered as one of the advantages of new nanocomposites films. These findings suggest that SF/PVA/AgNP/PDA-Mt films have potential clinical applications in wound dressing and antibacterial biomedical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Bacterial infection at wound sites can easily induce robust inflammation. M1 macrophages at wound sites can cause cascade inflammatory reactions to mediate a vicious inflammation cycle. Meanwhile, the hypoxia situation further aggravates the destruction and contraction of blood vessels in the wound microenvironment, therefore, hindering the infected wound healing process. Here, a thermosensitive hydrogel is reported to solve the above challenges by eliminating bacteria based on the photothermal effect, regulating the inflammatory immune microenvironment, and providing oxygen (O2). In vitro and in vivo experiments confirmed that the hydrogel has great O2‐producing properties. Based on the excellent photothermal properties of AIEgens, the hydrogel has a good bactericidal effect against S. aureus (100%) and E. coli (98.85%). The RNA‐sequencing revealed that Cur@AIE@MnO2/gel can interfere with the metabolic process and genetic material repair process to impact bacteria proliferation and biofilm dispersal, thus achieving excellent anti‐bacterial efficacy. Moreover, Cur@AIE@MnO2/gel can also up‐regulate anti‐inflammatory genes, down‐regulate pro‐inflammatory genes in macrophages, and facilitate the promotion of macrophage polarization from M1 to M2 to relieve inflammation. The therapeutic experiments show that this hydrogel accelerated the wound‐healing process. Therefore, this work may open new avenues for the development of novel dressings for bacterial‐infected wounds. [ABSTRACT FROM AUTHOR]

GO-COO-β-CD/CA inclusion (carboxylated graphene-β-cyclodextrin/chlorhexidine acetate) was fabricated with a graphene-based drug carrier. The reaction time and ratio of carrier to drug were optimized by X-ray diffraction spectra to ensure the complete wrapping of CA. Hemolysis test and recalcification test demonstrated that the inclusion possessed good blood compatibility due to the inherent biocompatibility of β-CD molecules in the carrier. The inclusion displayed excellent inhibition effect on both gram negative bacteria of Escherichia coli and gram positive bacteria of Staphylococcus Aureus, while showing no cytotoxicity. More importantly, the drug efficiency was greatly improved with CA dosage as less as one-third of the pure drug due to the synergistic effect of the drug and carrier. Dynamic simulation implies that the delivery profile of CA from the inclusion is in accordance with the first-order dynamic equation, i.e. ln(1 -Mt/M) = −kt. [ABSTRACT FROM AUTHOR]

Abstract: A graphite oxide (GO)/heparin–benzalkonium chloride (C12) composite was synthesized. The composite was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD data showed that spacing between layers of GO increased from 0.59 to 3.256nm. This enlarged layer spacing suggested that heparin–C12 complex intercalated completely in between layers of GO. FTIR also confirmed intercalation of heparin–C12 complex into GO gallery. In vitro release rate of heparin from GO–heparin–C12 was monitored for 30days. Heparin released at a very fast rate from the composite matrix in the first day. The release slowed down significantly after the first day and continued for 30days. In addition, antibacterial activity of the composite against Escherichia coli (E. coli) and Staphlococcus aureus (S. aureus) was evaluated using zone of inhibition and colony count assays. Both GO–heparin–C12 and GO–C12 clearly showed antibacterial activity against E. coli and S. aureus while GO alone has a relatively low activity against S. aureus and almost no effect on E. coli. [Copyright &y& Elsevier]

Nanocomposites are effective methods for the treatment of microbial infections. In this work, zinc oxide nanoparticles and silver nanoparticles were synthesized by a simple and mild method, and successfully loaded on polydopamine-modified montmorillonite (PDA Mt) to prepare nanocomposites (ZnO/Ag/PDA-Mt) with potent antibacterial ability. The transmission electron microscope (TEM) showed that the nanoparticles in ZnO/Ag/PDA-Mt were quasi-spherical, and the particle size ranged from 5 nm to 45 nm. The energy dispersive spectroscopy (EDS)-mapping verified the presence of Zn, Ag, O, Al, Si and C elements in the synthesized ZnO/Ag/PDA-Mt. In addition, the antimicrobial activity of ZnO/Ag/PDA-Mt was also tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Due to the synergistic antibacterial effect between zinc oxide nanoparticles and silver nanoparticles, ZnO/Ag/PDA-Mt exhibited higher antiseptic activity than silver nanoparticles supported polydopamine-modified montmorillonite (Ag/PDA-Mt) and zinc oxide nanoparticles supported polydopamine-modified montmorillonite (ZnO/PDA-Mt). The biocompatibility of ZnO/Ag/PDA-Mt was evaluated by cytotoxicity assay. The results demonstrated that the ZnO/Ag/PDA-Mt nanocomposites have potential for antibacterial applications. [Display omitted] • Zinc oxide nanoparticles and silver nanoparticles were successfully loaded on polydopamine-modified montmorillonite. • Nanoparticles in ZnO/Ag/PDA-Mt were uniformly distributed on the nanosheet of PDA-Mt in spherical form. • The ZnO/Ag/PDA-Mt can significantly enhance the antibacterial effect compared to Ag/PDA-Mt and ZnO/PDA-Mt. • The ZnO/Ag/PDA-Mt showed high cytocompatibility in L929 fibroblasts. [ABSTRACT FROM AUTHOR]

In this work, an effective method was explored to prepare silver nanoparticles/graphene oxide-sulfobutylether-β-cyclodextrin (AgNPs/GO-SBE-β-CD) antibacterial nanocomposite. Dopamine (DA) was used as a green and mild reductant to directly in situ reduce silver nitrate on Sulfobutylether-β-cyclodextrin (SBE-β-CD) modified graphene oxide (GO-SBE-β-CD). Its synthesized, antibacterial properties and biocompatibility were studied. Results showed that silver nanoparticles with an average size of 73 nm were uniformly distributed on the GO-SBE-β-CD sheets. In addition, AgNPs/GO-SBE-β-CD were proved an effective antibacterial material against both gram-negative and gram-positive, reduced the viability of E. coli and S. aureus by 90 % at 40 µg/mL. At the same time, AgNPs/GO-SBE-β-CD co-cultured with L929 cells did not show cytotoxicity. In vivo experiment, AgNPs/GO-SBE-β-CD showed good biocompatibility. Collectively, AgNPs/GO-SBE-β-CD is a promising material to prevent bacterial infection, expecting to be applied in wound healing. [Display omitted] • Dopamine was used as a reducing agent to reduce silver ions to AgNPs. • The AgNPs/GO-SBE-β-CD was prepared through an eco-friendly strategy. • The novel approach can reduce the agglomeration and biological toxicity. • The AgNPs/GO-SBE-β-CD has good antibacterial properties and biocompatibility. • The prepared nanocomposites are expected to be applied in wound infection fields. [ABSTRACT FROM AUTHOR]

• Mn SACs were developed for photothermal-catalytic antibacterial therapy. • The peroxidase-like catalytic activity of Mn SACs could generate abundant ROS. • The Mn SACs had better antibacterial effect against E. coli and S. aureus. • The Mn SACs promoted the palingenetic angiogenesis and wound healing. Bacteria-infected inflammation caused by the pathogenic bacteria have become a serious threat to patients. Moreover, multi-drug resistant infections due to the prescription of empiric antibiotics is still a big concern worldwide. Herein, spherical mesoporous manganese single atom catalysts (Mn SACs) are developed for photothermal-catalytic antibacterial therapy based on Pluronic F127 and dopamine hydrochloride using nano-emulsion assembly approach. The significant peroxidase-like catalytic activity of Mn SACs could generate abundant •OH in the presence of H 2 O 2. In addition, the catalytic activity of the Mn SACs was seen to be further enhanced with the assistance of its photothermal properties. In vitro antibacterial experiments confirmed that the synergetic catalyze therapy and photothermal therapy have better antibacterial effect against typical Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus). The cytotoxicity assay illustrated great biocompatibility of the Mn SACs, providing a possibility for its in vivo therapy application. Remarkably, the healing rate and immune fluorescence of E. coli infected wounds indicated that the synergetic treated group had better anti-infection response. This was concluded from alleviating the inflammation and enhancing palingenetic angiogenesis. In summary, this study provides a novel approach for synthesis of spherical mesoporous single-atom catalysts, which was used as an anti-infection agent and could be further explored in relevant biomedicine field. [ABSTRACT FROM AUTHOR]

The functionalization of polydimethylsiloxane (PDMS) nanocomposites with advanced nanostructure materials suggests that tailored control and objective design would create significant stages with improved mechanical properties and antimicrobial properties. This work designs a creative and easy technique for the binding of silver nanoparticles-lecithin modified montmorillonite (AgNPs@LEC-Mt) in PDMS nanocomposite for antibacterial Applications. The PDMS/ AgNPs@LEC-Mt nanocomposite was evaluated by XRD, FTIR, SEM and TEM analyses. PDMS/ AgNPs @LEC-Mt nanocomposites showed better thermal stability than pure PDMS by thermogravimetric analysis. The effect of AgNPs @ LEC-Mt on the mechanical properties of PDMS was studied. The mechanical property was the best among four of them when the content of AgNPs @ LEC-Mt within reaches 1%. PDMS / AgNPs @ LEC-Mt nanocomposites showed high antimicrobial activity against E. coli and S. aureus. In vitro experiments (cell experiments) and in vivo experiments (animal experiments) evaluated that PDMS/ AgNPs @LEC-Mt nanocomposites had excellent biocompatibility. The effortlessness of the procedure, the quick response time and the better antibacterial property is useful for the advancement of antimicrobial PDMS nanocomposites for medical antibacterial devices. Schematic demonstration of the biocidal functions of the nanocomposite film (A); SEM photographs and element mapping of bacterial of with and without treatment including (B) S. aureus and (C) E. coli by using PDMS/1 wt% AgNPs/LEC-Mt nanocomposite for 2 h [Display omitted] [ABSTRACT FROM AUTHOR]