Inhibitory effect of aptamer-carbon dot nanomaterial-siRNA complex on the metastasis of hepatocellular carcinoma cells by interfering with FMRP

Using small interfering RNA (siRNA) for the specific gene-silencing has been a novel therapeutic method for the treatment of incurable diseases such as malignancies. However, it remains a challenge whether siRNA can be safely and effectively delivered into target cells. Therefore, we synthesized fluorescent carbon dots (CDs) as a gene vector at the siRNA delivery system that induced efficient gene knockdown in vitro while binding aptamer AS1411 to resolve the difficulty in cell targeting. We found that CDs with adequate biocompatibility can improve the efficiency of cellular uptake of siRNA. CLSM and FCM results showed that CDs were mainly localized in the cytoplasm and emitted bright green fluorescence. In addition, the CD/siRNA delivery system mediated by the aptamer AS1411 effectively silenced the expression of Fragile X mental retardation protein (FMRP) and successfully inhibited the migration and invasive propensity of hepatocellular carcinoma (HCC) cells. In summary, we have synthesized a valuable siRNA delivery vector enabling not only bioimaging but also effective downregulation of gene expression, which is indicative of an efficient potential for gene delivery and therapy.