Abstract
The αvβ3 and αvβ5 integrins, transmembrane glycoprotein receptors, are over-expressed in numerous tumors and in endothelial cells that constitute tumor blood vessels. As this protein selectively binds to the Arg–Gly–Asp (RGD) sequence containing peptides, it is an attractive way to target tumors. Herein we have developed novel formulations for integrin mediated selective gene delivery. These formulations are composed of a novel palmitoylated tetrameric RGD containing scaffold (named RAFT-RGD), cationic gemini cholesterol (GL5) and a natural helper lipid 1,2-dioleoyl-L-α-glycero-3-phosphatidylethanolamine (DOPE). We have optimized a co-liposomal formulation to introduce the multivalent RGD-containing macromolecule in GL5: DOPE (GL5D) mixture to produce GL5D–RGD. We have unambiguously shown the selectivity of these formulations towards cancer cells that over express αvβ3 and αvβ5 integrins. Two reporter plasmids, pEGFP-C3 and PGL-3, were employed for the transfection experiments and it was shown that GL5D–RGD liposomes increased exclusively the transfection in αvβ3 and αvβ5-overexpressing HeLa cells.