Direct gene transfer into rat articular cartilage by in vivo electroporation

To establish a system for efficient direct in vivo gene targeting into rat joint, we have evaluated a strategy of gene transfer by means of the delivery of external electric pulses (EP) to the knee after intraarticular injection of a reporter gene (GFP). Rats were killed at various times after the electro gene‐therapy to analyze GFP gene expression by immunohistochemistry. GFP staining was detected in the superficial, middle, and deep zones of the patellar cartilage at days 2 and 9, and thereafter only in the deep zone (months 1 and 2). The average percentage of GFP‐positive cells was estimated at 30% both one and 2 months after the gene transfer. Moreover, no pathologic change caused by the EP was detected in the cartilage. The level and stability of the long‐term GFP expression found in this study demonstrate the feasibility of a treatment of joint disorders (inflammatory or degenerative, focal or diffuse) using electric gene transfer.—Grossin, L., Cournil‐Henrionnet, C., Mir, L. M., Liagre, B., Dumas, D., Etienne, S., Guingamp, C., Netter, P., Gillet, P. Direct gene transfer into rat articular cartilage by in vivo electroporation. FASEB J. 17, 829–835 (2003)