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Mechanisms of cellular uptake and intracellular trafficking with chitosan/DNA/poly(γ-glutamic acid) complexes as a gene delivery vector

Paper ID Volume ID Publish Year Pages File Format Full-Text
8420 589 2011 10 PDF Available
Title
Mechanisms of cellular uptake and intracellular trafficking with chitosan/DNA/poly(γ-glutamic acid) complexes as a gene delivery vector
Abstract

Chitosan (CS)-based complexes have been considered as a vector for DNA delivery; nonetheless, their transfection efficiency is relatively low. An approach by incorporating poly(γ-glutamic acid) (γ-PGA) in CS/DNA complexes was developed in our previous study to enhance their gene expression level; however, the detailed mechanisms remain to be understood. The study was designed to investigate the mechanisms in cellular uptake and intracellular trafficking of CS/DNA/γ-PGA complexes. The results of our molecular dynamic simulations suggest that after forming complexes with CS, γ-PGA displays a free γ-glutamic acid in its N-terminal end and thus may be recognized by γ-glutamyl transpeptidase in the cell membrane, resulting in a significant increase in their cellular uptake. In the endocytosis inhibition study, we found that the internalization of CS/DNA complexes took place via macropinocytosis and caveolae-mediated pathway; by incorporating γ-PGA in complexes, both uptake pathways were further enhanced but the caveolae-mediated pathway played a major role. TEM was used to gain directly understanding of the internalization mechanism of test complexes and confirmed our findings obtained in the inhibition experiments. After internalization, a less percentage of co-localization of CS/DNA/γ-PGA complexes with lysosomes was observed when compared with their CS/DNA counterparts. A greater cellular uptake together with a less entry into lysosomes might thus explain the promotion of transfection efficiency of CS/DNA/γ-PGA complexes. Knowledge of these mechanisms involving CS-based complexes containing γ-PGA is critical for the development of an efficient vector for DNA transfection.

Keywords
Lysosome; Macropinocytosis; Caveolae-mediated pathway; Transfection efficiency; Cellular uptake
First Page Preview
Mechanisms of cellular uptake and intracellular trafficking with chitosan/DNA/poly(γ-glutamic acid) complexes as a gene delivery vector
Publisher
Database: Elsevier - ScienceDirect
Journal: Biomaterials - Volume 32, Issue 1, January 2011, Pages 239–248
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering