Insulin-like growth factor-I liposomal gene transfer and systemic growth hormone stimulate wound healing.
Many of the anabolic effects of growth hormone (GH) act through insulin-like growth factor-I (IGF-I). Systemic administration of GH in combination with IGF-I has been shown to stimulate wound reepithelialization, however, it causes hyperglycemia or hypoglycemia, respectively. We hypothesize that very low doses of IGF-I in a liposome form will have the same positive wound-healing effect when administered locally as the higher doses of GH plus IGF-I given systemically. To test this hypothesis, rats were given a 40% TBSA full-thickness scald injury and received either placebo IGF-I (5.0 mg/kg/day, subcutaneously), IGF-I liposome (0.9 microgram/kg/week, subcutaneously), or a combination of GH and IGF-I, or IGF-I liposomes for 8 weeks. GH in combination with IGF-I showed a significant increase in postburn weight. Wound reepithelialization, measured by computerized planimetry as percentage original wound area, was significantly increased in rats receiving GH plus IGF-I, GH plus IGF-I liposomes, and IGF-I liposomes when compared to sham, or IGF-I (p < 0.05). Results indicate that small doses of IGF-I, delivered in the form of liposomes, are equally effective in increasing burn wound reepithelialization as the higher doses of GH plus IGF-I, or GH plus IGF-I liposomes.
Pierre
E J
EJ
Department of Surgery, University of Texas Medical Branch, Galveston, USA.
Perez-Polo
J R
JR
Mitchell
A T
AT
Matin
S
S
Foyt
H L
HL
Herndon
D N
DN
D000818:Animals; D002056:Burns / Q000628:therapy*; D004337:Drug Carriers; D018014:Gene Transfer Techniques; D013006:Growth Hormone / Q000008:administration & dosage* / Q000494:pharmacology; D007279:Injections, Subcutaneous; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage* / Q000494:pharmacology; D008081:Liposomes; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014945:Wound Healing / Q000502:physiology*
D004337:Drug Carriers; D008081:Liposomes; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone