OBJECTIVETo evaluate the effects of mixed grafting of vascular endothelial cells and fibroblasts on the angiogenesis of artificial dermis.

METHODSFull-thickness skin defects with the size of 2. 5 cm x 2. 5 cm were made on the back of 27 Wistar rats, and they were randomized into endothelium group ( cultured vascular endothelial cells were mixed into 0. 5 ml fibrin glue, and evenly sprayed onto wound bed in density of 1.0 x 10(5)/cm(2) before artificial dermis grafting) , mixed grafting group( cultured vascular endothelial cells and fibroblasts were mixed into 0. 5ml fibrin glue, and evenly sprayed onto wound bed in density of 1.0 x 10(5)/cm(2) before artificial dermis grafting) , and control group( with spraying of equal amount of fibrin glue on the wound bed). Each group consisted of 9 rats and 18 wounds. On 5 and 10 post-grafting day (PGF) , the grafts and surrounding tissue were harvested for the observation of neo-vascular growth with HE staining, VEGF antibody staining, Masson's trichrome staining and India ink staining. Evans blue perfusion method was also used to measure the angiogenesis of micro-vascular vessels on 5 PGD.

RESULTSThe growth of new vessels was observed in each group on 5 PGD with HE staining, VEGF antibody staining, Masson's trichrome staining and India ink staining. Under high power field, the number of new vessels in endothelium and mixed grafting groups was (14. 2 3.6) and (12.1 +/- 2. 5) , which were obviously higher than that in control group (3.9 +/- 1.6, P < 0.05). On 10 PGD, angiogenesis and increased synthesis of collagen tissue were observed in both wound bed and artificial dermis. On 5 PGD, the amount of absorbed Even blue extracted from the grafted dermis in endothelium group (0. 167 +/-0. 058) and mixed grafting group (0. 155 +/- 0. 046) was significantly higher than that in control group (0. 066+/-0. 024, P <0. 05).

CONCLUSIONMixed grafting of homogenous vascular endothelial cells and fibroblasts is beneficial for the promotion of neovascularization, acceleration of angiogenesis and maturation of artificial dermis during the wound healing process.