title: Intracellular delivery of proteins in complexes with oligoarginine-modified liposomes and the effect of oligoarginine length.
abstract: The intracellular delivery of proteins using cell-penetrating peptides (CPPs) including oligoarginine (oligo-Arg) carriers raises the possibility of establishing novel therapeutic methods. We compared the effect of the length of oligo-Arg in modified liposomes ((Arg)(n)-L; n = 4, 6, 8, 10) on the delivery of proteins by flow cytometry, fluorescence microscopy, and spectrofluorimetry. As a free liposome, Arg4-modified liposome Arg4-L was most efficiently internalized in cells. The efficiency decreased depending on the length of oligo-Arg. For the intracellular delivery of proteins, (Arg)(n)-L was physically associated with proteins. Concerning the effect of oligo-Arg length, liposome/protein complexes showed a different behavior. Arg4-L carried bovine serum albumin (BSA, 66 kDa) and beta-galactosidase (beta-Gal, 120 kDa) 6-fold higher than free BSA and free beta-Gal. Arg10-L showed similar performance for these two proteins to Arg4-L. The enzymatic activity of beta-Gal in the cells showed that proteins were transported as a biologically active form. Arg10-L carried 100-fold more immunoglobulin G (IgG, 150 kDa) than free IgG, and 3-fold more than Arg4-L into cells. Shorter oligo-Arg chain on liposomes may be enough for liposomes alone to be taken up in cells, but more Arg residues may be needed to form a complex with high molecular weight proteins and deliver them into cells. This information will aid in the design of (Arg)(n)-L as a carrier for delivering proteins into cells.
authors.affiliation: Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Furuhata
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kawakami
authors.forename: Kazunori
authors.initials: K
authors.lastname: Toma
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hattori
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Maitani
mesh_terms: D001120:Arginine / Q000737:chemistry*; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D008081:Liposomes; D008856:Microscopy, Fluorescence; D011506:Proteins / Q000008:administration & dosage*
chemical_list: D008081:Liposomes; D011506:Proteins; D001120:Arginine