A Gold Nanoparticle Platform for the Delivery of Functional TGF-<I>β</I>1 siRNA Into Cancer Cells

Nanoparticles, especially gold nanoparticles (AuNPs), have been shown to be an efficient carrier to deliver small RNAs into cancer cells. In this study, we used cysteamine-functionalized AuNPs to effectively deliver TGF-β1 siRNA into hepatoma HepG2 cells in vitro and in vivo. We found that, compared with AuNPs-mediated NC siRNA (AuNP-siNC), AuNPs-delivered TGF-β1 siRNA (AuNP-siTGFβ1) efficiently decreased the level of TGF-β1, increased cell apoptosis, and significantly inhibited the proliferation of recipient tumour cells. Systemic administration of the AuNP-siTGFβ1 complexes into human HepG2 xenografted mice likewise reduced TGF-β1 expression and downstream TGF-β1 signalling. Functionally, AuNP-siTGFβ1 strongly inhibited tumour growth and improved the survival rate of tumour-bearing mice compared with the control groups. In conclusion, our results demonstrate that the siRNA delivery system with AuNP described here appears to be a highly effective method to deliver RNAi therapeutics into tumour cells for oncotherapy.