Recently, a research article entitled "Anti-tumor effects in mice induced by survivin-targeted siRNA delivered through polysaccharide nanoparticles" in Prof. Gao Zhonggao' group in the State Key Laboratory of Bioactive Substance and Function of Natural Medicines has been published by the international authorized journal "Biomaterials" in the fields of biomaterials and pharmaceutics. Currently, this article is available online (http://dx.doi.org/10.1016/j.biomaterials.2013.03.047).
By inducing RNA interference response, small interfering RNA (siRNA) can specifically down-regulate the expression of target genes, which provides a promising therapeutic method for serious diseases, especially various cancers. Because vector is required to protect and deliver siRNA into cells to play its therapeutic effect, the study on highly efficient vectors for siRNA delivery becomes a very hot topic, and also is a major research field in Prof. Gao' group. Recently, they directly grafted TAT peptides at the site of primary amino groups in chitosan (CS) molecules to synthesize the novel copolymer TAT-g-CS as non-viral vector for siRNA delivery. TAT-g-CS vector could load siRNA to form nanoparticles with the average particle size of about 200 nm, and these nanoparticles were able to deliver siRNA into cells to down-regulate the expression of target genes. Moreover, TAT-g-CS vector was used to load the siRNA targeting survivin gene to prepare nanoparticles for anti-tumor therapy. It was demonstrated that these TAT-g-CS/siRNA nanoparticles could not only effectively inhibit the proliferation of tumor cells in vitro, but also show the strong inhibitory effect on the growth and metastasis of malignant breast tumor in vivo. Generally, this study provided a new strategy for siRNA drug delivery and anti-tumor therapy.
