Tailor-made curdlan based nanofibrous dressings enable diabetic wound healing

The development and application of novel polysaccharides that can improve diabetic wound healing is crucial. Dressings containing curdlan have the potential to promote healing in diabetic wounds, but the underlying mechanism remain unclear. In addition, the functional modifications that could further enhance the activity of curdlan in promoting diabetic wound healing have not been explored. Herein, we investigated the capabilities of curdlan (CU) and its four derivatives i.e., sulfated curdlan (SC), amino-curdlan (AC) carboxymethyl curdlan (CMC) and CMC/ZnO nanocomposites for diabetic wound healing. Pristine CU and its derivatives were blended with polyvinyl alcohol (PVA) to fabricate electrospun nanofiber dressings (ENDs) with uniform appearances. The PVA/CU, PVA/CMC and PVA/CMC-ZnO ENDs were more compatible with keratinocytes, fibroblasts, and macrophages than that of PVA/AC ENDs. Notably, PVA/CMC ENDs and PVA/CMC-ZnO ENDs exhibited superior wound healing efficiencies than other ENDs. Among various dressings, PVA/CU, PVA/SC, PVA/CMC ENDs effectively reduced M1 macrophages and facilitated M2 phenotype at early stage of diabetic wound healing. Collectively, the PVA/CMC ENDs demonstrated greater therapeutic potential against diabetic wounds compared to other modified scaffolds via regulating macrophage polarization.