title: Amphiphilic graft copolymer based on poly(styrene-co-maleic anhydride) with low molecular weight polyethylenimine for efficient gene delivery.
abstract: METHODS
  A new amphiphilic comb-shaped copolymer (SP) was synthesized by conjugating poly(styrene-co-maleic anhydride) with low molecular weight polyethyleneimine for gene delivery. Fourier transform infrared spectrum, (1)H nuclear magnetic resonance, and gel permeation chromatography were used to characterize the graft copolymer.
  
  
  RESULTS
  The buffering capability of SP was similar to that of polyethyleneimine within the endosomal pH range. The copolymer could condense DNA effectively to form complexes with a positive charge (13-30 mV) and a small particle size (130-200 nm) at N/P ratios between 5 and 20, and protect DNA from degradation by DNase I. In addition, SP showed much lower cytotoxicity than polyethyleneimine 25,000. Importantly, the gene transfection activity and cellular uptake of SP-DNA complexes were all markedly higher than that of complexes of polyethyleneimine 25,000 and DNA in MCF-7 and MCF-7/ADR cell lines.
  
  
  CONCLUSIONS
  This work highlights the promise of SP as a safe and efficient synthetic vector for DNA delivery.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China.
authors.forename: Xiaopin
authors.initials: X
authors.lastname: Duan
authors.forename: Jisheng
authors.initials: J
authors.lastname: Xiao
authors.forename: Qi
authors.initials: Q
authors.lastname: Yin
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shirui
authors.initials: S
authors.lastname: Mao
authors.forename: Yaping
authors.initials: Y
authors.lastname: Li
mesh_terms: D004247:DNA / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics*; D004058:Diffusion; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D061986:MCF-7 Cells; D008299:Maleic Anhydrides / Q000737:chemistry*; D008970:Molecular Weight; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure; D011094:Polyethyleneimine / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D014162:Transfection / Q000379:methods*
chemical_list: D008299:Maleic Anhydrides; D053769:Nanocapsules; D011137:Polystyrenes; D011094:Polyethyleneimine; D004247:DNA