Evaluation of dendrimer type bio-reducible polymer as a siRNA delivery carrier for cancer therapy.

Small interfering ribonucleic acid (siRNA), 20-25 base pairs in length, can interfere with the expression of specific genes. Recently, many groups reported the therapeutic intervention of siRNA in various cancer cells. In this study, dendrimer type bio-reducible polymer (PAM-ABP) which was synthesized using arginine grafted bio-reducible poly(cystaminebisacrylamide-diaminohexane) (ABP) and polyamidoamine (PAMAM) was used to deliver anti-VEGF siRNA into cancer cell lines including human hepatocarcinoma (Huh-7), human lung adenocarcinoma (A549), and human fibrosarcoma (HT1080) cells and access their potential as a siRNA delivery carrier for cancer therapy. PAM-ABP and siRNA formed polyplexes with average diameter of 116 nm and charge of around +24.6 mV. The siRNA in the PAM-ABP/siRNA polyplex was released by 5mM DTT and heparin. VEGF gene silencing efficiency of PAM-ABP/siRNA polyplexes was shown to be more effective than PEI/siRNA polyplexes in three cell lines with the following order HT1080>A549>Huh-7.