The Primary Research On Antitumor Application Of Silver Nanoparticles Mediated By Cell Penetrating Peptide

Objective:The purpose of this study was to investigate the anti-tumor activity of silver nanoparticles (AgNP) to search for new therapeutic approaches for cancer. Currently, it has been reported that AgNP possessed in vitro anti-tumor activity, especially the one less than10nm in size.Methods:AgNP was prepared using chemical reduction method, and the synthesis process was optimized through single-factor experiments. To improve the cell-penetrating ability, AgNP was superficially modified with the cell-penetrating peptide (TAT), termed AgNP-TAT. The particle size and electric potential of AgNP and AgNP-TAT were determined by laser nanometer particle size analyzer. The morpHology of AgNP and AgNP-TAT were analyzed by transmission electron microscope. Qualitative and quantitative determinations of TAT modification were carried out using TGA and BCA assay. The cellular uptake efficacy of AgNP and AgNP-TAT was evaluated by Confocal and FACS. The inhibitory effect of AgNP and AgNP-TAT against tumor cells and normal cells was analyzed through MTT assay. Finally, the tumor suppression effect of AgNP and AgNP-TAT against melanoma was evaluated by nude mice model implanted with melanoma. In all in vitro and in vivo assay, douxorubicin (ADR) was set as a positive control.Results:The main factors that affected the particle size of AgNP were the ratio of silver nitrate and sodium borohydride, the amount of surfactant PVP k-30, stirring speed and time during preparation. The AgNP with a mean size of8nm was finally prepared through optimized method and was conjugated with TAT on its surface through Ag-S covalent bond. In vitro experiments showed that both AgNP and AgNP-TAT had significant cytotoxicity on several kinds of tumor cells, while the AgNP-TAT displayed greatly enhanced antitumor activity due to its improved cell penetration. However, both of them showed no significant cellular toxicity against normal cell line of HEK293-T. In vivo experiments showed that the anti-tumor effect of AgNP-TAT against the melanoma cells implanting in nude mice was promising, with tumor regression rate up to90%, while displaying significantly reduced side effects compared to ADR.Conclusion:The AgNP prepared in this study with particle size less than10nm was demonstrated its anti-tumor effect both in vitro and in vivo. Furthermore, the activity was greatly improved by TAT modifiction. Both in vitro and in vivo experiment showed the promising anti-tumor effect of AgNP-TAT More importantly, the in vitro experiment showed AgNP-TAT acted on the MDR cells and non-resistant cells in a discriminate manner, demonstrating the potential application in anti-tumor (especially multidrug resistance tumor).