OBJECTIVETo investigate the feasibility of differentiation of bone marrow mesenchymal stem cells (MSCs) into vascular endothelial cells and the mechanism of its involvement in wound healing.

METHODSPorcine MSCs were harvested from porcine marrow, and they were isolated and purified by density gradient centrifugation. After being cultured and amplified in vitro, the MSCs were labelled with BrdU (5-bromodeoxy-uridine). Full skin loss wound was created on the back of the mini-swine whose bone marrow was obtained. The labelled MSCs with fibrin glue as the vector were regrafted back to the donor animal wound. The wound tissue specimens were harvested at 2, 4, 6, 8 and 12 post-operation weeks and were immunohistochemically stained by BrdU and factor VIII (FVIII) for comparative study.

RESULTSMost BrdU positive cells aggregated around small blood vessels in the granulation tissue of the wounds. Only individual vascular endothelial cells were BrdU positive. There was FVIII expression in the cytoplasm of BrdU positive cells.

CONCLUSIONMSCs were closely correlated with the formation of small blood vessels in granulation tissue during wound healing process. The porcine MSCs possessed the potential to differentiate into vascular entoehelial cells and to participate in wound healing under the micro-enviroment of the wound.