Controllable Aggregation-Induced Exocytosis Inhibition (CAIEI) of Plasmonic Nanoparticles in Cancer Cells Regulated by MicroRNA.

Recent advances in nanotechnology have produced plenty of intracellular drug delivery systems based on various functional nanoparticles. Although much progress has been achieved in improving cellular uptake efficiency, the retention time of these engineered nanoparticles in living cells has not yet received wide attention. Here, we report the controllable exocytosis of plasmonic gold nanoparticles (GNPs) based on a microRNA-21 (miRNA-21) targeted binary system. Rapid intracellular accumulation of GNPs was observed in miRNA-21 positive MCF-7 breast cancer cells, which blocked the exocytosis of the GNP aggregates. Under near-infrared (NIR) irradiation, MCF-7 cells were successfully killed due to the far-red and NIR absorption of the GNP aggregates. In contrast, in miRNA-21 negative cells, the dispersive GNPs escaped from the cells after 6 h. The traces of GNPs could be conveniently captured under the dark-field microscope. This work provides a promising platform for the study of controllable aggregation-induced exocytosis inhibition (CAIEI) of nanocarriers, which is inspiring for the design of more effective nanodrugs for the treatment of cancer.