MOF/MXene-loaded PVA/chitosan hydrogel with antimicrobial effect and wound healing promotion under electrical stimulation and improved mechanical properties.

Electrical stimulation modulates cell behavior and influences bacterial activity, so highly conductive, antimicrobial hydrogels are suitable for promoting wound healing. In this study, highly conductive and antimicrobial Ti3C2Tx (MXene) hydrogels composed of chitosan and poly(vinyl alcohol) and AgCu- H2PYDC MOF were developed. In PVACS/MOF/MXene (PCMM) hydrogels, the MXene layer acts as an electrical conductor. The electrical conductivity is 0.61 ± 0.01 S·cm-1. PCMM hydrogels modulate cell behavior and provide ES antimicrobial capacity under ES at 1 V. The metal ions of MOF form coordination with chitosan molecules and increase the cross-linking density between chitosan molecules, thus improving the mechanical properties of the hydrogel (tensile strength 0.088 ± 0.04 MPa, elongation at break 233 ± 11 %). The PCMM gels had good biocompatibility. The PCMM hydrogels achieved 100 % antibacterial activity against E. coli and S. aureus for 12 h. 1 V electrical stimulation of PCMM hydrogel accelerated the wound healing process in mice by promoting cell migration and neovascularization, achieving 97 ± 0.4 % wound healing on day 14. The hydrogel dressing PCMM-0.1 with MOF addition of 0.1 % had the best wound healing promoting effect and which is a promising dressing for promoting wound healing and is a therapeutic strategy worth developing.

Bimetal-Organic Framework-Loaded PVA/Chitosan Composite Hydrogel with Interfacial Antibacterial and Adhesive Hemostatic Features for Wound Dressings.

Silver-containing wound dressings have shown attractive advantages in the treatment of wound infection due to their excellent antibacterial activity. However, the introduction of silver ions or AgNPs directly into the wound can cause deposition in the body as particles. Here, with the aim of designing low-silver wound dressings, a bimetallic-MOF antibacterial material called AgCu@MOF was developed using 3, 5-pyridine dicarboxylic acid as the ligand and Ag+ and Cu2+ as metal ion sites. PCbM (PVA/chitosan/AgCu@MOF) hydrogel was successfully constructed in PVA/chitosan wound dressing loaded with AgCu@MOF. The active sites on the surface of AgCu@MOF increased the lipophilicity to bacteria and caused the bacterial membrane to undergo lipid peroxidation, which resulted in the strong bactericidal properties of AgCu@MOF, and the antimicrobial activity of the dressing PCbM was as high as 99.9%. The chelation of silver ions in AgCu@MOF with chitosan occupied the surface functional groups of chitosan and reduced the crosslinking density of chitosan. PCbM changes the hydrogel crosslinking network, thus improving the water retention and water permeability of PCbM hydrogel so that the hydrogel has the function of binding wet tissue. As a wound adhesive, PCbM hydrogel reduces the amount of wound bleeding and has good biocompatibility. PCbM hydrogel-treated mice achieved 96% wound recovery on day 14. The strong antibacterial, tissue adhesion, and hemostatic ability of PCbM make it a potential wound dressing.