3D Electrospun nanofiber sponges of insect chitosan/pullulan/citric acid embedded with ZnMOF in situ for enhanced healing of MRSA-infected wounds

In biomedicine, one of the major challenges is effectively promoting wound healing of bacterial infections. Current wound dressings (e.g., gauze and bandages) are far from meeting the needs of the population as they lack various bioactivities to promote wound healing (including hemostasis, antimicrobial, anti-inflammatory, promotion of tissue regeneration, etc.) and are not biodegradable. In this study, we prepared an insect chitosan/pullulan/citric acid three-dimensional, layered electrospun nanofiber sponge embedded with ZnMOF in situ (3D-ZnMOF) and used it to promote MRSA-infected wound healing. The fabrication method and physicochemical characteristics of 2D nanofiber membranes and 3D nanofiber sponges were thoroughly assessed. SEM-EDS, XPS, XRD, and FT-IR were used to characterize the 3D-ZnMOF sponges, and the release behavior of zinc ions was examined. Experiments conducted both in vitro and in vivo demonstrated the hemostatic characteristics, biocompatibility, and antibacterial activity of 3D-ZnMOF sponges. 3D-ZnMOF sponges showed the ability to promote wound contraction, accelerate collagen deposition, inhibit inflammatory factors, and promote angiogenesis in an MRSA-infected rat whole-skin wound model. Consequently, 3D-ZnMOF nanofiber sponges offer a great deal of promise for accelerating the healing of wounds infected with drug-resistant bacteria.