title: Linear polyethylenimine-graft-chitosan copolymers as efficient DNA/siRNA delivery vectors in vitro and in vivo.
abstract: Chitosan was partially converted to its chlorohydrin derivative by the reaction with epichlohydrin, which was subsequently reacted with varying amounts of lPEI(2.5 kD) to obtain a series of chitosan-lPEI(2.5 kD) 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(2.5 kD), bPEI(25 kD) 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 (2.5 kD) 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.
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Delhi University, Delhi, India.
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Tripathi
authors.forename: Ritu
authors.initials: R
authors.lastname: Goyal
authors.forename: Pradeep
authors.initials: P
authors.lastname: Kumar
authors.forename: Kailash C
authors.initials: KC
authors.lastname: Gupta
mesh_terms: D000327:Adsorption / Q000187:drug effects; D000818:Animals; D002021:Buffers; D016466:CHO Cells; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000008:administration & dosage*; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000008:administration & dosage*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D018613:Microscopy, Confocal; D010316:Particle Size; D010957:Plasmids / Q000378:metabolism; D011094:Polyethyleneimine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000633:toxicity; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage*; D055672:Static Electricity; D014162:Transfection
chemical_list: D002021:Buffers; D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; C551320:chitosan-graft-polyethylenimine; D011094:Polyethyleneimine; D004247:DNA; D048271:Chitosan; D006180:Proton-Translocating ATPases