In order to develop a new gene delivery vector, a novel cationic poly(organophosphazene) was synthesized by stepwise nucleophilic substitutions of poly(dichlorophosphazene) with a hydrophilic methoxy-poly(ethylene glycol) (MPEG) as a shielding group and a branched tetra(l-lysine), LysLys(LysEt)2, as a cationic moiety. The cationic polymer has shown to form a polyplex by DNA condensation and very low in vitro cytotoxicity probably due to the shielding effect of MPEG, which provides a basis for improving the low gene transfection yield of cationic polyphosphazenes.
Bibliographical noteFunding Information:
This work was supported by a Korean Research Foundation Grant (KRF-2004-005-C00090), by the SRC program of the Korea Science and Engineering Foundation through the Center for Intelligent Nano-Bio Materials at Ewha Womans University (Grant R11-2005-008-01002-0), and by Ministry of Commerce, Industry and Energy of Korea.
- Non-viral vector