title: Carbon dioxide-modified polyethylenimine as a novel gene delivery vector and its in vitro validation.
abstract: In this work, the CO2-modified polyethylenimine, as a novel delivery vector, has been validated by combining with the plasmid DNA to form plasmid DNA/CO2-modified polyethylenimine complexes. We have modified polyethylenimine using CO2to partially convert amine groups to carbamic acid groups. The buffering capacity and the plasmid DNA binding ability of the CO2-modified polyethylenimine and PEI-25 (polyethylenimine with Mw = 25 kDa) were characterized by acid-base titration and agarose gel electrophoresis, respectively. The particle size and zeta potential of the complexes were determined using a Zetasizer Nano ZS. Resistance to nuclease digestion was determined via DNase I protection assay. The cytotoxicity was measured by the MTT assay. The transfection efficiency of the complexes has been evaluated by flow cytometry. It is observed that the condensation capacity of CO2-modified polyethylenimine is still comparable to polyethylenimine and the CO2-modified polyethylenimine can protect plasmid DNA from degradation by DNase I. The diameter of the plasmid DNA/CO2-modified polyethylenimine complex is around 140 nm and the zeta potential decreases. MTT assays confirm that the cytotoxicity is much lower for plasmid DNA/CO2-modified polyethylenimine than for plasmid DNA/PEI-25. The flow cytometry found that in serum-free medium the transfection efficiency can reach a value of ∼60% for plasmid DNA/CO2-modified polyethylenimine, and in 10% fetal bovine serum medium, the transfection efficiency is still as high as ∼40%, which is much higher than that of plasmid DNA/PEI-25. CO2-modified polyethylenimine could be a novel and promising nonviral gene vector for gene therapy.
authors.affiliation: 1 Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, Shanghai, China.
authors.forename: Dongjie
authors.initials: D
authors.lastname: Shao
authors.affiliation: 1 Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, Shanghai, China.
authors.forename: Hanbing
authors.initials: H
authors.lastname: Wu
authors.affiliation: 1 Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, Shanghai, China.
authors.forename: Fawei
authors.initials: F
authors.lastname: Shen
authors.affiliation: 2 Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Switzerland.
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.affiliation: 1 Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, Donghua University, Shanghai, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Quan
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000737:chemistry*; D002460:Cell Line; D004247:DNA / Q000235:genetics; D004337:Drug Carriers; D006801:Humans; D051379:Mice; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D010957:Plasmids; D011094:Polyethyleneimine / Q000737:chemistry*; D013499:Surface Properties; D014162:Transfection / Q000379:methods
chemical_list: D004337:Drug Carriers; D002245:Carbon Dioxide; D011094:Polyethyleneimine; D004247:DNA
keywords: CO2; Poly(ethyleneimine) derivatives; gene delivery; in vitro validation; nonviral vector