International Journal of Nanomedicine (Mar 2010)

The investigation of polymer-siRNA nanoparticle for gene therapy of gastric cancer in vitro

  • Ying Wu,
  • Weiwei Wang,
  • Yinting Chen,
  • et al

Journal volume & issue
Vol. 2010, no. default
pp. 129 – 136

Abstract

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Ying Wu1, Weiwei Wang2, Yinting Chen1, Kaihong Huang1, Xintao Shuai2, Qikui Chen1, Xuexian Li1, Guoda Lian11Department of Gastroenterology, The Second Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China; 2BME Center, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, ChinaAbstract: Small interfering RNA (siRNA) molecules have significant therapeutic promise for the genetic treatment of cancer. To overcome instability and low transfection efficiency, polyethylene glycol-polyethyleneimine (PEG-PEI) was synthesized and investigated as a non-viral carrier of siRNA targeting CD44v6 in gastric carcinoma cells. The size, surface charge using zeta potential, and morphology via scanning electron microscopy (SEM) of PEG-PEI/siRNA nanoparticles was characterized, and their cytotoxicity, transfection efficiency, and interaction with SGC7901 human gastric carcinoma cells was evaluated. The transfection efficiency of PEG-PEI/siRNA nanocomplexes was dependant on the charge ratio between amino groups of PEG-PEI and phosphate groups of siRNA (N/P) values, which reflected the molar ratio of PEG-PEI to siRNA during complex formation. The transfection efficiency of PEG-PEI/siRNA at N/P 15 was 72.53% ± 2.38%, which was higher than that observed using Lipofectamine 2000 and PEI as delivery carriers. Cytotoxicity of PEG-PEI was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and was obviously lower than that of PEI. Moreover, when N/P was below 15, PEG-PEI/siRNA was less toxic than Lipofectamine 2000/siRNA. RT-PCR (real time polymerase chain reaction) and Western blot analyses of CD44v6 expression demonstrated the gene silencing effect of PEG-PEI/siRNA at N/P 15. These data indicate that PEG-PEI may be a promising non-viral carrier for altering gene expression in the treatment of gastric cancer with many advantages, such as relatively high gene transfection efficiency and low cytotoxicity.Keywords: siRNA, PEG-PEI, nanoparticles, CD44v6 gene, gastric carcinoma cells