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

Original Research

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Authors: Ying Wu, Weiwei Wang, Yinting Chen, et al

Published Date March 2010 Volume 2010:5 Pages 129 - 136

DOI: http://dx.doi.org/10.2147/IJN.S8503

Ying Wu¹, Weiwei Wang², Yinting Chen¹, Kaihong Huang¹, Xintao Shuai², Qikui Chen¹, Xuexian Li¹, Guoda Lian¹

¹Department 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, China

Abstract: 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