Yolk-shell structured Au nanorods@mesoporous silica for gas bubble driven drug release upon near-infrared light irradiation

Drug release systems co-encapusulated with ammonium bicarbonate (ABC) could facilitate drug release upon acidic or thermal stimulations to improve therapeutic effect. However, it is not easy to control drug release rate, owing to relative stable temperature and acidic condition in living body. Besides, the additional loaded ABC reduces drug loading capacity. Herein, a near-infrared light triggered rapid drug release system with high loading capacity was developed by loading ABC and doxorubicin into yolk-shell structured Au nanorods@mesoporous silica. Gas bubbles were generated from the thermolysis of ABC utilizing photothermal effect of Au nanorods to extrude drug molecules. The mesoporous silica shell was finally destroyed along with growing bubbles, resulting in burst drug release. The photothermal therapeutic effect of Au nanorods also contributed in tumor treatment. The excellent therapeutic effect was demonstrated in cancer cells and tumor-bearing mice, which provides a new reference to achieve controllable rapid drug release in cancer medicine. A gas bubble promoted drug release system is developed by loading ammonium bicarbonate (ABC) and doxorubicin in yolk-shell structured Au nanorods@mesoporous silica, achieving both high loading capacity and near-infrared light excitation. The growing bubbles generated from thermolysis of ABC, which is triggered by photothermal effect of Au nanorods, accelerate burst drug release, resulting in excellent therapeutic efficacy in living cancer cells and tumor-bearing mice. [Display omitted] •A gas bubble promoted drug release system was developed by loading ammonium bicarbonate and doxorubicin in yolk-shell structured Au nanorods@mesoporous silica.•The drug release system achieved burst drug release upon near-infrared light irradiation and high drug loading capacity.•The therapeutic effect was demonstrated in living cancer cells and tumor-bearing mice.