TAT-liposomes: a novel intracellular drug carrier.

TAT peptide was attached to the surface of plain and PEGylated liposomes. These TAT peptide-modified liposomes have been shown to translocate into a variety of normal and cancer cells if a non-hindered interaction between the cell surface and liposome-attached TAT peptide was made possible. TAT peptide-liposomes translocated into cells remain intact within first few hours as proved by a co-localization of fluorescent markers entrapped inside liposomes and incorporated into the liposomal membrane. After 2 hours liposomes had slowly migrating towards cell nuclei. Liposomes had completely disintegrated with their inner marker released by approximately 9 hours. TAT peptide-liposomes were made slightly cationic by adding up to 10 mol %. of a cationic lipid (DOTAP). These slightly cationic liposomes were non-toxic towards cells, formed firm complexes with DNA (plasmid encoding for the formation of the Green Fluorescent Protein), and efficiently transfected a variety of cells. TAT peptide-liposomes can be considered as promising carriers for the non-endocytotic intracellular delivery of drugs and DNA.