title: Comparisons of three polyethyleneimine-derived nanoparticles as a gene therapy delivery system for renal cell carcinoma.
abstract: BACKGROUND
  Polyethyleneimine (PEI), which can interact with negatively charged DNA through electrostatic interaction to form nanocomplexes, has been widely attempted to use as a gene delivery system. However, PEI has some defects that are not fit for keeping on gene expression. Therefore, some modifications against PEI properties have been done to improve their application value in gene delivery. In this study, three modified PEI derivatives, including poly(ε-caprolactone)-pluronic-poly(ε-caprolactone) grafted PEI (PCFC-g-PEI), folic acid-PCFC-isophorone diidocyanate-PEI (FA-PEAs) and heparin-PEI (HPEI), were evaluated in terms of their cytotoxicity and transfection efficiency in vitro and in vivo in order to ascertain their potential application in gene therapy.
  
  
  METHODS
  MTT assay and a marker GFP gene, encoding green fluorescent protein, were used to evaluate cell toxicity and transfection activity of the three modified PEI in vitro. Renal cell carcinoma (RCC) models were established in BALB/c nude mice inoculated with OS-RC-2 cells to detect the gene therapy effects using the three PEI-derived nanoparticles as gene delivery vehicles. The expression status of a target gene Von Hippel-Lindau (VHL) in treated tumor tissues was analyzed by semiquantitative RT-PCR and immunohistochemistry.
  
  
  RESULTS
  Each of three modified PEI-derived biomaterials had an increased transfection efficiency and a lower cytotoxicity compared with its precursor PEI with 25-kD or 2-kD molecule weight in vitro. And the mean tumor volume was obviously decreased 30% by using FA-PEAs to transfer VHL plasmids to treat mice RCC models. The VHL gene expression was greatly improved in the VHL-treated group. While there was no obvious tumor inhibition treated by PCFC-g-PEI:VHL and HPEI:VHL complexes.
  
  
  CONCLUSIONS
  The three modified PEI-derived biomaterials, including PCFC-g-PEI, FA-PEAs and HPEI, had an increased transfection efficiency in vitro and obviously lower toxicities compared with their precursor PEI molecules. The FA-PEAs probably provide a potential gene delivery system to treat RCC even other cancers in future.
authors.affiliation: State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, P. R. China
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Xu
authors.forename: Guobo
authors.initials: G
authors.lastname: Shen
authors.forename: Xiangying
authors.initials: X
authors.lastname: Xia
authors.forename: Xinyu
authors.initials: X
authors.lastname: Zhao
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Wu
authors.forename: Qingfa
authors.initials: Q
authors.lastname: Guo
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Qian
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Wei
authors.forename: Shufang
authors.initials: S
authors.lastname: Liang
mesh_terms: D002292:Carcinoma, Renal Cell / Q000628:therapy*; D045744:Cell Line, Tumor; D015316:Genetic Therapy; D006801:Humans; D007680:Kidney Neoplasms / Q000628:therapy*; D053758:Nanoparticles