PLGA@IL-8 nanoparticles-loaded acellular dermal matrix as a delivery system for exogenous MSCs in diabetic wound healing

Diabetic chronic wounds are not only accompanied by inflammation and ulcers but also cause amputation when they develop into severe diabetic foot. Mesenchymal stem cells (MSCs) have been proven to ameliorate diabetic wound healing, however, the low survival rate of exogenous MSCs after transplantation into the highly proteolytic wound environment is a major obstacle to effective stem cell therapy. Herein, to improve the proliferation, differentiation, and anti-apoptosis ability of transplanted MSCs, we prepared Poly (lactic-co-glycolic acid) (PLGA) nanoparticles encapsulated with anti-inflammatory and angiogenic cytokine IL-8, then loaded the nanospheres on acellular dermal matrix to fabricate an efficient delivery medium (PLGA@IL-8/ADM) for exogenous MSCs. It was observed that, in the PLGA@IL-8-loaded ADM, MSCs presented significant proliferation and endothelial differentiation with a great survival rate. In addition, PLGA@IL-8/ADM laden with MSCs effectively induced the capillary construction, collagen deposition and wound healing in cutaneous wounds of streptozotocin-induced diabetic mice. Further immunofluorescence analysis indicated that proangiogenic factors (VEGF and α-SMA) were upregulated in regenerated tissue. Overall, our findings indicated that PLGA@IL-8/ADM-MSCs was a potential therapeutic dressing that may contribute to the therapy of diabetic wounds and the PLGA@IL-8/ADM scaffold would be a novel delivery system for exogenous cells for tissue regeneration.