¹Shriners Hospital for Children, University of Texas Medical Branch, Galveston, Texas, USA

²Shriners Hospital for Children Department of Surgery, University of Texas Medical Branch, Galveston, Texas, USA

³Shriners Hospital for Children Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas, USA

⁴Department of Neurosurgery, University of Texas Medical School, Houston, Texas, USA

Correspondence to: MG Jeschke, Shriners Hospital for Children, 815 Market Street, Galveston, Texas 77550, USA

Exogenous insulin-like growth factor-I (IGF-I) is known to improve the pathophysiology of a thermal injury, however, deleterious side-effects have limited its utility. Cholesterol-containing cationic liposomes that encapsulate complementary DNA (cDNA) are nonviral carriers used for in vivo gene transfection. We propose that liposome IGF-I gene transfer will accelerate wound healing in burned rats and attenuate deleterious side-effects associated with high levels of IGF-I. To test this hypothesis IGF-I gene constructs, encapsulated in liposomes, were studied for their efficacy in modulating the thermal injury response. Thirty adult male Sprague-Dawley rats were given a 60% TBSA scald burn and randomly divided into three groups to receive weekly subcutaneous injections of liposomes plus the lacZ gene coding for -galactosidase, liposomes plus cDNA for IGF-I and -galactosidase or liposomes plus the rhIGF-I protein. Body weights and wound healing were measured. Muscle and liver dry/wet weights and IGF-I concentrations in serum, skin and liver were measured by radioimmunoassay. Transfection was confirmed by histochemical staining for -galactosidase. Rats receiving the IGF-I cDNA constructs exhibited the most rapid wound re-epithelialization and greatest increase in body weight and gastrocnemius muscle protein content (P < 0.05). local igf-i protein concentrations in the skin were higher when compared to liposomes containing only the lacz gene (p < 0.05) transfection was apparent in the cytoplasm of myofibroblasts, endothelial cells and macrophages of the granulation tissue. liposomes containing the igf-i gene constructs proved effective in preventing muscle protein wasting and preserving total body weight after a severe thermal injury.

growth factor; insulin-like growth factor-I; liposomes; trauma; wound healing