Cationic Fluorescent Gold Nanoclusters for Nonviral siRNA Delivery

RNA interference (RNAi) strategy based on small interfering RNA (siRNA) has become a standard method in biomedical research. In recent years, RNAi has also made remarkable advances in clinical translation. However, the conventional cationic vectors for siRNA delivery have severe disadvantages such as low delivery efficiency , high cytotoxicity and lack of imaging function , which severely restrict the clinical translation of siRNA drugs. To address the shortcomings of conventional siRNA vectors, we herein reported a cationic gold nanocluster (CGN) -based nanovectors for siRNA delivery and fluorescence imaging. Firstly, we used BSA template to synthesize GN by biomineralization strategy. Then, the BSA-templated GN was modified with ethylene diamine (EDA) or ethylene dimethyl amine (DMA) to form CGN. We demonstrated that the CGN can efficiently deliver siRNA and significantly silence green fluorescence protein (GFP) expression in A549-GFP lung cancer cells. Finally, we investigated the ability of CGN 14 fluorescence tracing in vitro by using confocal laser scanning microscopic examination. This study demonstrated the potential of the CGN for siRNA delivery and fluorescence tracing in vitro.