title: N-isopropylacrylamide-modified polyethylenimines as effective gene carriers.
abstract: 25 kDa branched polyethylenimines are modified by N-isopropylacrylamide via Michael addition. An agarose gel retardation assay shows that all derivatives display good binding affinity toward plasmid DNA. The modified PEI-25K shows lower cytotoxicity in MTT assay and better transfection efficiency than unmodified PEI-25K in HeLa cells. The endocytosis efficiency of the optimized complexes is determined to be 99.9% by flow cytometry. More interestingly, although the derivatives are not designed to conjugate with targeting ligands or nuclear localization signals, confocal laser scanning microscopy (CLSM) demonstrates that the optimized derivative results in increased endocytosis and strongly enhanced nuclear uptake compared with PEI-25K.
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
authors.forename: Huayu
authors.initials: H
authors.lastname: Tian
authors.forename: Feifan
authors.initials: F
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Yubin
authors.initials: Y
authors.lastname: Huang
authors.forename: Xuesi
authors.initials: X
authors.lastname: Chen
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D004247:DNA / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D004705:Endocytosis / Q000502:physiology; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D015394:Molecular Structure; D010316:Particle Size; D010957:Plasmids / Q000378:metabolism; D011094:Polyethyleneimine / Q000737:chemistry* / Q000627:therapeutic use; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000178:Acrylamides; D013778:Tetrazolium Salts; D013844:Thiazoles; D011094:Polyethyleneimine; D004247:DNA; C067295:N-isopropylacrylamide; C022616:thiazolyl blue