Linear polyethylenimine-graft-chitosan copolymers as efficient DNA/siRNA delivery vectors in vitro and in vivo

• Published in: Nanomedicine 2012-04, Vol.8 (3), p.337-345
• Main Authors: Tripathi, Sushil K., MSc, Goyal, Ritu, MPhil, Kumar, Pradeep, PhD, Gupta, Kailash C., PhD
• Format: Article
• Language: English
• Subjects: Adsorption - drug effects; Animals; Buffering capacity; Buffers; Cell Survival - drug effects; Chitosan; Chitosan - analogs & derivatives; Chitosan - chemistry; Chitosan - toxicity; CHO Cells; Confocal microscopy; Copolymers; Cricetinae; Cricetulus; DNA; DNA - administration & dosage; Endosomes - drug effects; Endosomes - metabolism; Enzyme Inhibitors - pharmacology; Gene expression; Gene Expression Regulation - drug effects; Gene Transfer Techniques; Genetic Vectors - administration & dosage; HEK293 Cells; HeLa Cells; Humans; In vivo gene expression; Internal Medicine; Intracellular Space - drug effects; Intracellular Space - metabolism; Intravenous administration; lPEI(2.5kD); Mice; Mice, Inbred BALB C; Microscopy, Confocal; nanotechnology; Particle Size; pH effects; Plasmids - metabolism; Polyethyleneimine - analogs & derivatives; Polyethyleneimine - chemistry; Polyethyleneimine - toxicity; Proton-Translocating ATPases - antagonists & inhibitors; Proton-Translocating ATPases - metabolism; Reporter gene; RNA, Small Interfering - administration & dosage; siRNA; Spleen; Static Electricity; Transfection
• ISSN: 1549-9634; 1549-9642
• DOI: 10.1016/j.nano.2011.06.022

Abstract Chitosan was partially converted to its chlorohydrin derivative by the reaction with epichlohydrin, which was subsequently reacted with varying amounts of lPEI(2.5kD) to obtain a series of chitosan-lPEI(2.5kD) copolymers (CP). These copolymers were then characterized and evaluated in terms of transfection efficiency (in vitro and in vivo), cell viability, DNA release and buffering capacity. The CP-4 copolymer (the best among the CP series) showed enhanced transfection (~ 2 – 24 folds) in comparison with chitosan, lPEI(2.5kD), bPEI(25kD) and Lipofectamine in HEK293, HeLa and CHO cells. The buffering capacity (in the pH range of 3 – 7.5), as shown by confocal microscopy, and DNA-release capability of the CP copolymers, was found to be significantly enhanced over chitosan. Intravenous administration of CP-4/DNA polyplex in mice followed by the reporter gene analysis showed the highest gene expression in spleen. Collectively, these results demonstrate the potential of CP-4 copolymer as a safe and efficient nonviral vector. From the Clinical Editor Chitosan –PEI (2.5kD) copolymers (CP) were characterized and their transfection efficiency, DNA release and buffering capacity were studied. The CP-4 copolymer significantly enhanced buffering capacity and provided the highest gene expression levels. The method may be used to enhance DNA transfection.