Fabrication of a smart drug delivery system based on hollow Ag.sub.2S@mSiO.sub.2 nanoparticles for fluorescence-guided synergistic photothermal chemotherapy

A novel near-infrared (NIR) light-triggered smart nanoplatform has been developed for cancer targeting and imaging-guided combined photothermal-chemo treatment. Notably, Ag.sub.2S has a dual function of photothermal therapy and fluorescence imaging, which greatly simplifies the structure of the system. It can emit fluorescence at 820 nm under an excitation wavelength of 560 nm. The phase-change molecule of 1-tetradecanol (TD) is introduced as a temperature-sensitive gatekeeper to provide the nanocarrier with controlled release capability of doxorubicin (DOX). The nanocarrier (HAg.sub.2S@mSiO.sub.2-TD/DOX) shows a high drug loading capacity of 26.3% and exhibits an apparent NIR-responsive DOX release property. Under NIR irradiation, the photothermal effect of HAg.sub.2S nanocores facilitated the release of DOX through the melting of TD. The cytotoxicity test shows that the nanocarriers have good biocompatibility. As the same time, the synergistic combination leads to a better cancer inhibition effect than individual therapy alone in vitro. Cell uptake tests indicate that the carriers have excellent fluorescence imaging ability and high cellular uptake for HepG2 cells. This work provides a new strategy for the fabrication of smart nanocarriers with simple structures for fluorescence-mediated combination cancer therapy. Graphical abstract Fabrication of a smart drug delivery system based on hollow Ag.sub.2S@mSiO.sub.2 nanoparticles for fluorescence-guided synergistic photothermal chemotherapy