Preparation of exosomes encapsulated nanohydrogel for accelerating wound healing of diabetic rats by promoting angiogenesis.

Exosomes derived from human umbilical cord mesenchymal stem cells (HUCMSCs) were helpful for injury repair, but whether HUCMSCs-derived exosomes could be encapsulated in a novel nanohydrogel to regulate diabetic wound healing was unclear. Here, HUCMSCs-derived exosomes encapsulated in a bioactive scaffold composed of polyvinyl alcohol (PVA)/alginate (Alg) nanohydrogel (exo@H) was applied to wound healing of diabetic rats. Results found that exo@H could facilitate the proliferation, migration and angiogenesis of HUVECs and sped up the process of diabetic wound healing. We confirmed that exo@H contributed to the expression of the molecules related to wound healing, including SMA, SR-B1 and CD31. Besides, we also found that exo@H up-regulated VEGF level via regulating ERK1/2 pathway. These data demonstrated that exo@H significantly accelerated healing of diabetic wounds in rats by promoting angiogenesis.