Galactosylation of chitosan-graft-spermine as a gene carrier for hepatocyte targeting in vitro and in vivo

J Nanosci Nanotechnol. 2012 Jul;12(7):5178-84. doi: 10.1166/jnn.2012.6376.

Abstract

Polyethyleneimine (PEI) has been described as a highly efficient gene carrier due to its efficient proton sponge effect within endosomes. However, many studies have demonstrated that PEI is toxic and associated with a lack of cell specificity despite high transfection efficiency. In order to minimize the toxicity of PEI, we prepared chitosan-graft-spermine (CHI-g-SPE) in a previous study. CHI-g-SPE showed low toxicity and high transfection efficiency. However, this compound also had limited target cell specificity. In the present study, we synthesized galactosylated CHI-g-SPE (GCS) because this modified GCS could be delivered specifically into the liver due to hepatocyte-specific galactose receptors. The DNA-binding properties of GCS at various copolymer/DNA weight ratios were evaluated by a gel retardation assay. The GCS copolymer exhibited significant DNA-binding ability and efficiently protected DNA from nuclease attack. Using energy-filtered transmission electron microscopy (EF-TEM), we observed dense spherical, nano-sized GCS/DNA complexes with a homogenous distribution. Most importantly, GCS was associated with remarkably low cytotoxicity compared to PEI in HepG2, HeLa, and A549 cells. Moreover, GCS carriers specifically delivered the gene-of-interest into hepatocytes in vitro as well as in vivo. Our results suggest that the novel GCS described here is a safe and highly efficient carrier for hepatocyte-targeted gene delivery.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Chitosan / chemistry*
  • DNA / administration & dosage
  • DNA / pharmacokinetics*
  • Drug Carriers / chemical synthesis
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / metabolism*
  • Male
  • Mice
  • Mice, Transgenic
  • Nanocapsules / chemistry*
  • Spermine / chemistry*
  • Transfection / methods*

Substances

  • Drug Carriers
  • Nanocapsules
  • Spermine
  • DNA
  • Chitosan