PNIPAM-Based Hydrogel-loaded Dicliptera Chinensis Polysaccharides -treated ADSC- derived exosomes promotes angiogenesis to accelerate healing in skin wound model

Background Promotion ofangiogenesis is a key aspect in accelerating wound healing. Therefore, exosomal therapy is a promising method for wound healing. Dicliptera Chinensis Polysaccharides (DCPs) have the potential to promote angiogenesis in tissues, and a hydrogel loaded with exosomes is an ideal delivery carrier. This study investigated the mechanism by which Pnipam-based hydrogel-loaded adipose-derived stem cell exosomes(ADSC-Exos) are stimulated by DCP in skin wound healing. Methods Exosomes secreted by adipose stem cells (ADSC-exosomes) was collected after stimulation DCP stimulation (DExos). In vitro experiments verified the ability of DExos to promote angiogenesis using the cell scratch technique, angiogenesis assay, RT-qPCR and Western Blotting using human umbilical vein endothelial cells (HUVEC) as a cell model. In vivo, a full skin defect was created on the backs of rats and Pnipam-based hydrogels loaded with DExo were injected into the defect. Wound healing was assessed morphologically and histologically. Results DExos promoted the cell migration rate and vasculogenic capacity of HUVECs and increased the cellular expression levels of CD 31, FGF 2, and VEGF-A. DExos-based poly(N-isopropylacrylamide) hydrogels (Pnipam@DExos) enabled the sustained release of DExos from the Pnipam-based hydrogel, which maintained high local concentrations at the wound site, promoting skin wound healing. Conclusion Pretreatment of ADSCs with DCPs improves the vasculogenic capacity of exosomes and pnipam@DExos promotes skin wound healing by slowly releasing DExos.