Biodegradable polyphosphoester micelles for gene delivery.


Journal Article

A new biodegradable polyphosphoester, poly[[(cholesteryl oxocarbonylamido ethyl) methyl bis(ethylene) ammonium iodide] ethyl phosphate] (PCEP) was synthesized and investigated for gene delivery. Carrying a positive charge in its backbone and a lipophilic cholesterol structure in the side chain, PCEP self-assembled into micelles in aqueous buffer at room temperature with an average size of 60-100 nm. It could bind and protect plasmid DNA from nuclease digestion. Cell proliferation assay indicated a lower cytotoxicity for PCEP than for poly-L-lysine and Lipofectamine. The IC50 determined by the WST-1 assay was 69.8, 51.6, and 12.1 microg/mL for PCEP, Lipofectamine, and poly-L-lysine, respectively. PCEP efficiently delivered DNA to several cell lines such as HEK293, Caco-2, and HeLa. The highest efficiency was achieved when PCEP/DNA complex was prepared in Opti-MEM with a +/- charge ratio of 1.5-2. The transfection efficiency did not change significantly when the complex was used 3 days after preparation. The addition of chloroquine to the formulation increased transfection efficiency 10- to 50-fold compared to the complex alone. In vivo studies showed a luciferase expression by PCEP/DNA complexes in muscle increasing with time during 3 months, although the expression level was lower than that by direct injection of naked DNA. In addition to biodegradability and lower toxicity, the PCEP micelle carrier offers structural versatility. The backbone charge density and the side chain lipophilicity are two parameters that can be varied through copolymerization and monomer variation to optimize the transfection efficiency.

Full Text

Cited Authors

  • Wen, J; Mao, H-Q; Li, W; Lin, KY; Leong, KW

Published Date

  • August 2004

Published In

Volume / Issue

  • 93 / 8

Start / End Page

  • 2142 - 2157

PubMed ID

  • 15236461

Pubmed Central ID

  • 15236461

Electronic International Standard Serial Number (EISSN)

  • 1520-6017

International Standard Serial Number (ISSN)

  • 0022-3549

Digital Object Identifier (DOI)

  • 10.1002/jps.20121


  • eng