Acceleration of diabetic wound healing with adipose-derived stem cells, endothelial-differentiated stem cells, and topical conditioned medium therapy in a swine model

The purpose of our study was to investigate the effect of adipose-derived stem cells (ASCs), endothelial-differentiated ASCs (EC/ASCs), and various conditioned media (CM) on wound healing in a diabetic swine model. We hypothesized that ASC-based therapies would accelerate wound healing. Diabetes was induced in four Yorkshire swine through intravenous injection of streptozotocin. ASCs were harvested from flank fat and cultured in either M199 or EGM-2 medium. A duplicate series of seven full-thickness dorsal wounds were surgically created on each swine. The wounds in the cellular treatment group underwent injection of low-dose or high-dose ASCs or EC/ASCs on day 0, with a repeat injection of one half of the initial dose on day 15. Wounds assigned to the topical CM therapy were covered with 2 mL of either serum-free M199 primed by ASCs or human umbilical vein endothelial cells every 3 days. Wounds were assessed at day 0, 10, 15, 20, and 28. The swine were sacrificed on day 28. ImageJ software was used to evaluate the percentage of wound healing. The wounded skin underwent histologic, reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay examinations to evaluate markers of angiogenesis and inflammation. We found an increase in the percentage of wound closure rates in cell-based treatments and topical therapies at various points compared with the untreated control wounds (P < .05). The results from the histologic, messenger RNA, and protein analyses suggested the treated wounds displayed increased angiogenesis and a diminished inflammatory response. Cellular therapy with ASCs, EC/ASCs, and topical CM accelerated diabetic wound healing in the swine model. Enhanced angiogenesis and immunomodulation might be key contributors to this process. The purpose of the present study was to translate the known beneficial effects of adipose-derived stem cells and associated conditioned medium therapy on diabetic wound healing to a large animal model. We demonstrated that stem cell and conditioned medium therapy significantly accelerate gross wound healing in diabetic swine, with data suggesting this might result from a decreased inflammatory response and increased angiogenesis.