Fluorescent silicon nanoparticle-based gene carriers featuring strong photostability and feeble cytotoxicity

Safe fluorescent gene-transfection vectors are in great demand for basic biological applications and for gene-therapy research. Here, we introduce a new type of luminescent silicon nanoparticle (SiNP)-based gene carrier suitable for determining the intracellular fate of the gene vehicle in a long-term and real-time manner. The presented SiNP-based nanocarriers simultaneously feature strong and stable fluorescence, high DNA-loading capacity and gene-transfection efficiency, as well as favorable biocompatibility. Taking advantage of these unique benefits, we were able to readily observe the behavior of the gene carriers in live cells (e.g. cellular uptake, intracellular trafficking, and endosomal escape) in a long-term and real-time manner. The results demonstrate the potential usability of these fluorescent SiNP-based gene vectors as powerful tools in the field of gene therapy, and provide invaluable information for understanding the intracellular behavior of gene carriers.