Porous chitin nanofibers combined with adipose-derived stem cells promote diabetic wound healing via PPAR-γ activation.

Chronic wounds of diabetes are one of the serious complications that cause disability or death in patients with diabetes, posing a significant clinical challenge. Therefore, porous chitin nanofibers (CR) were prepared from silk and squid cartilage, and combined with adipose-derived stem cells (ADSCs) transplantation to promote wound healing in type 2 diabetes mellitus (T2DM) in this study. The results of scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) indicated that the CR had an obvious three-dimensional porous structure. The in vivo and in vitro degradation experiments showed that the CR had good degradability. The live/dead staining and hemolysis experiments demonstrated that the CR had good biocompatibility. The results of in vivo experiments indicated the results of H&E staining and masson staining indicated that the CR combined with the ADSCs transplantation significantly accelerated the wound healing of T2DM mice. Immunohistochemical staining indicated that the CR combined with the ADSCs transplantation significantly increased collagen deposition and cell proliferation, and regulated macrophage expression. In addition, the CR combined with the ADSCs transplantation can increase the expression of α-SMA and VEGF-A to promote angiogenesis. Proteomics sequencing and western blotting experiments revealed that the CR combined with the ADSCs transplantation accelerated wound healing by activating the PPAR-γ signaling pathway to regulate the expressions of MMP-1, SCD-1 and ACOX-2. To sum up, all these results suggested that the CR combined with the ADSCs transplantation could provide a promising method for wound healing in T2DM.