title: A study of thermoresponsive poly(N-isopropylacrylamide)/polyarginine bioconjugate non-viral transgene vectors.
abstract: A thermoresponsive poly(N-isopropylacrylamide)/poly(l-arginine)bioconjugate (PNIPArg) was prepared by radical polymerization and EDC-activated coupling. The lower critical solution temperature (LCST) of PNIPArg aqueous solution determined by turbidimetry was around 35.2 degrees Celsius. The transmission electron microscope (TEM) showed that the PNIPArg/DNA complexes appeared uniform nanospheres with size about 50-120nm. Variable temperature circular dichroism (CD) and gel electrophoresis results revealed that the association and dissociation of PNIPArg/DNA complexes could be tuned by varying temperature; polyarginine (PArg) showed no temperature-controllable change of DNA condensate. Incorporation of PNIPAAm considerably decreased the cytotoxicity of PArg. The transfection level of PNIPArg and PArg was evaluated with COS-1 cells using two different reporter genes, pGL3-Control encoding luciferase and pEGP-C1 encoding green fluorescent protein (GFP). The transfection efficiency of PNIPArg incubated at 37 degrees Celsius for 22h, 20 degrees Celsius for 2h and 37 degrees Celsius for 24h was enhanced to a different extent depending on PNIPArg/DNA ratios compared to that incubated at 37 degrees Celsius for 48h. Encouragingly, at PNIPArg/DNA mass ratio of 3/1, the transfection efficiency of PNIPArg obtained with variable temperature route was equivalent to that of Lipofectamine 2000.
authors.affiliation: School of Materials Science and Engineering, Tianjin University, Tianjin 300072, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Cheng
authors.forename: Wenguang
authors.initials: W
authors.lastname: Liu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Cao
authors.forename: Weihang
authors.initials: W
authors.lastname: Ji
authors.forename: Dongchun
authors.initials: D
authors.lastname: Liang
authors.forename: Gang
authors.initials: G
authors.lastname: Guo
authors.forename: Jingyu
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000180:Acrylic Resins / Q000138:chemical synthesis / Q000737:chemistry*; D000818:Animals; D019556:COS Cells; D002470:Cell Survival; D002522:Chlorocebus aethiops; D002942:Circular Dichroism; D004587:Electrophoresis, Agar Gel; D005822:Genetic Vectors / Q000737:chemistry / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D013696:Temperature; D014162:Transfection / Q000379:methods; D019076:Transgenes / Q000235:genetics*
chemical_list: D000180:Acrylic Resins; D010455:Peptides; D049452:Green Fluorescent Proteins; C052970:poly-N-isopropylacrylamide; C015462:polyarginine; D008156:Luciferases