Efficient gene expression in skin wound sites following local plasmid injection

Transfection of the skin by local gene delivery, as well as widespread tran sfection of systemic tissues following intravenous injection of cationic li posome/DNA complexes have been reported. Here, we show that surgically woun ded mouse skin can be transfected either by local injection of DNA alone or by intravenous injection of optimized cationic liposome/DNA complexes; how ever, direct cutaneous injection produces much higher levels of gene expres sion in the skin, which is targeted to dermal and subdermal layers. High le vels of chloramphenicol acetyltransferase activity were present from 3 h to 2 wk following direct injection of a gene expression plasmid into wounded skin and were maintained at detectable levels up to 8 wk after injection. E xpression of transferred chloramphenicol acetyltransferase as well as beta -GAL genes was localized to fibroblasts, macrophages, and adipocytes as det ermined by histochemistry and immunohistochemistry. Furthermore, local inje ction of a human granulocyte-colony-stimulating factor gene expression plas mid produced high levels of the biologically relevant human granulocyte-col ony-stimulating factor protein in wounded mouse skin. This efficient and si mple method of site-specific gene transfer into wounds may lead to the deve lopment of cutaneous gene therapy directed against disorders of abnormal cu taneous wound healing.