Preparation and characterization of laminin-derived peptide AG73-coated liposomes as a selective gene delivery tool

Targeted gene delivery to cancer cells is considered as a promising strategy for cancer therapy. Since, several targeting ligands have been studied for cancer gene therapy, such as transferrin, folate, anisamide, RGD-peptide, and antibodies. We have focused on AG73 peptide, which is derived from the globular domain of the laminin α1 chain. AG73 peptide is known as a ligand for syndecans, one of the major heparin sulfate-containing transmembrane proteoglycans. Syndecan-2 is highly expressed in various cancer cells and plays a role in angiogenesis. In this study, we prepared AG73-labeled polyethyleneglycol-modified liposomes (AG73-PEG liposomes) for gene delivery tool to syndecan-2 overexpressing cancer cells, and assessed the characterization of AG73-PEG liposomes. We confirmed the conjugation of AG73 peptide to PEG liposomes by reverse-phase high-performance liquid chromatography analysis. Electron microscopy analysis showed that monodiseperse AG73-labeled lipsomes were prepared. We also assessed the gene transfection efficiency of AG73-PEG liposomes in syndecan-2 overexpressing cancer cells or syndecan-2 less expressing cancer cells. As a result, AG73-mediated liposomal gene transfection efficiency was increased by 100-fold in syndecan-2 overexpressing cancer cells compared to syndecan-2 less expressing cancer cells. These results suggested that AG73-PEG liposomes were successfully prepared from a point of view of the modification of AG73 peptide to PEG-liposomes and the particle size of liposomes, which presented nano size. Furthermore, our results suggest that AG73-PEG liposomes can be a useful targeted gene delivery vehicle for syndecan-2 overexpressing cancer cells.