Overexpression of vascular endothelial growth factor accelerates early vascularization and improves healing of genetically modified cultured skin substitutes.
Cultured skin substitutes (CSS) lack a vascular plexus, leading to slower vascularization after grafting than split-thickness skin autograft. CSS containing keratinocytes genetically modified to overexpress vascular endothelial growth factor (VEGF) were previously shown to exhibit enhanced vascularization up to 2 weeks after grafting to athymic mice. The present study examines whether enhanced vascularization compared with controls persists after stable engraftment is achieved and analyzes VEGF expression, wound contraction, and engraftment. Control and VEGF-modified (VEGF+) CSS were grafted onto full-thickness wounds in athymic mice. VEGF expression was detected in VEGF+ CSS 14 weeks after grafting. Graft contraction was significantly lower in VEGF+ CSS compared with controls, suggesting more stable engraftment and better tissue development. Positive HLA-ABC staining, indicating persistence of human cells, was seen in 86.7% (13/15) of grafted VEGF+ CSS, compared with 58.3% (7/12) of controls. Differences in dermal vascularization between control and VEGF+ grafts were significant 1 week after surgery, but not at later times. However, the distribution of vessels was different, with more vessels in the upper dermis of VEGF+ grafts. These results suggest that VEGF overexpression in genetically modified CSS acts to accelerate early graft vascularization and can contribute to improved healing of full-thickness skin wounds.
Supp
Dorothy M
DM
The Shriners Hospitals for Children, Cincinnati Burns Hospital, Cincinnati, Ohio 45229, USA.
Boyce
Steven T
ST
D000328:Adult; D000818:Animals; D002102:Cadaver; D016228:Endothelial Growth Factors / Q000235:genetics*; D005821:Genetic Techniques; D015234:HLA-A Antigens / Q000032:analysis; D015235:HLA-B Antigens / Q000032:analysis; D015236:HLA-C Antigens / Q000032:analysis; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D008222:Lymphokines / Q000235:genetics*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D012867:Skin / Q000098:blood supply* / Q000503:physiopathology; D016038:Skin Transplantation / Q000379:methods*; D013997:Time Factors; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014945:Wound Healing
D016228:Endothelial Growth Factors; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D008222:Lymphokines; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors