Treatment of ischemic wounds using cultured dermal fibroblasts transduced retrovirally with PDGF-B and VEGF121 genes

The healing of ischemic wounds is a particularly difficult clinical challenge. In this study, rabbit dermal fibroblasts transduced retrovirally with human platelet-derived growth factor B (PDGF-B) and human vascular endothelial growth factor 121 (VEGF121) genes were used to treat wounds in a rabbit ischemic ear model. The PDGF-B and VEGF121 genes were obtained from human umbilical vein endothelial cells (HUVECs) by reverse transcription-polymerase chain reaction, cloned into retroviral vectors under control of the beta-actin promoter, and introduced into primary rabbit dermal fibroblast cells. In vitro results demonstrated that rabbit dermal fibroblasts are transduced and selected readily using retroviral vectors, and are engineered to secrete PDGF-B and VEGF121 at steady-state levels of 150 ng per 10(6) cells per 24 hours and 230 ng per 10(6) cells per 24 hours respectively. These cells were then seeded onto polyglycolic acid (PGA) scaffold matrices and used to treat ischemic rabbit ear wounds. Immunohistochemistry showed intense staining for PDGF-B and VEGF121 in the wounds treated with these transduced cells compared with the control treatment groups. For the relatively more ischemic distal ear wounds, granulation tissue deposition was increased significantly in the wounds treated with PDGF-B- and VEGF121-transduced cells compared with wounds treated with PGA alone. These results demonstrate that gene augmentation of rabbit dermal fibroblasts with the PDGF-B and VEGF121 genes introduced into this ischemic wound model via PGA matrices modulates wound healing, and may have clinical potential in the treatment of ischemic wounds.