Covalent attachment of an influenza hemagglutinin-derived peptide to urethane-based cationic polymers affects their transfection efficiency in DNA delivery and their course in cell entry

摘要

In this study, an influenza hemagglutinin-derived peptide (HAP) was covalently linked to urethane-based cationic polymers (polyurethanes; PUs) to further improve their transfection efficiency. N-succinimidyl 3-(2-pyridylditio)propionate (SPDP) was used as a coupling agent. The peptide-conjugated PUs (with 2-4 peptides conjugated per polymer chain) resulted in conjugated PU/DNA complexes with greatly increased transfection efficiency in comparison with PU/DNA complexes made with PUs without HAP. This increased transfection efficiency came from the assistance of the cationic PUs in overcoming the cell membrane barrier and the ability of the conjugated viral peptide to destabilize the endolysosome membrane before degradation of the complexes. Furthermore, the modification of the cationic PUs through the introduction of poly-L-arginine (PA) into their side chains increased their capability for condensation with DNA, resulting in the smaller-sized complexes observed and contributing to their passage of DNA delivery. In vitro transfection and cytotoxicity data showed that the PU grafted with 1 degrees amine, PA, and HAP (i.e., PU-PA-1-HAP) exhibited substantially higher transfection activity than the PUs grafted without HAP, without PA or without HAP/PA (i.e., PU-PA-1, PU-1-HAP PU-1). Most of the cells were viable (90% cell survival) after transfection with cationic-PUs and HAP-conjugated PUs below a polymer/DNA ratio of 400/1 (w/w).