The impact of vascular endothelial growth factor containing collagen-binding domain on fat graft survival

Fat grafting is widely used in esthetic and reconstructive surgery; however, graft survival and volume retention are often suboptimal, particularly in fibrotic tissues following radiotherapy (RT). Vascular endothelial growth factor (VEGF) enhances angiogenesis but has limited efficacy due to its short half-life. We evaluated a modified VEGF containing a collagen-binding domain (CBD-VEGF) for improving fat graft survival in irradiated fibrotic tissue.

Twenty-four Sprague-Dawley rats were randomly allocated into three groups (n=8). All received a single 10 Gy dose of RT to the dorsal region to induce fibrosis. After one month, Group 1 received fat graft only, Group 2 received fat graft + VEGF, and Group 3 received fat graft + CBD-VEGF. Two months postgrafting, the grafts were harvested for weight measurement and histological evaluation, which included fibrosis and necrosis scoring and immunohistochemical staining for CD31 (vascular density) and perilipin-1 (adipocyte viability).

Group 3 (CBD-VEGF) demonstrated significantly higher graft weight compared to Groups 1 and 2 (p<0.01). Fibrosis and necrosis scores were significantly reduced in Group 3 (p<0.01 and p<0.05, respectively). CD31 and perilipin-1 expression levels were significantly elevated in Group 3 compared to both control and VEGF groups (p<0.01 and p<0.05).

CBD-VEGF significantly enhanced fat graft survival and improved tissue quality in irradiated fibrotic beds. Its application may represent a promising therapeutic strategy to optimize outcomes in fat grafting, particularly in previously irradiated tissues.