Boosting the tumor photothermal therapy with hollow CoSnSx-based injectable hydrogel via the sonodynamic and dual-gas therapy

Photothermal therapy (PTT) has attracted considerable attention in the field of nanomedicine owing to its high efficiency, low invasiveness, and precise controllability. However, limited by the activation of the immune system by PTT and the low penetrating ability of near-infrared lasers, the use of a single PTT is usually ineffective. Herein, a unique injectable hydrogel system was strategically designed and fabricated using CoSnSx, L-arginine, chitosan (CTS), and carboxymethyl cellulose (CMC) for sonodynamic and dual-gas therapy cooperative PTT. CoSnSx with a hollow structure can not only produce a large amount of singlet oxygen (1O2) under ultrasonic (US) irradiation, but also produce H2S gas in an acidic environment, so as to achieve sonodynamic and gas therapeutic effects. Additionally, CoSnSx exhibited excellent photothermal conversion efficiency of 48.24% under 808 nm laser irradiation. As a precursor of NO, L-arginine is incorporated into the hydrogel to enable the controlled release of NO under US/laser irradiation, thereby enhancing the PTT effect. Such a multifunctional injectable hydrogel system can achieve high therapeutic efficacy through sonodynamic and dual-gas treatment-enhanced PTT, as demonstrated by both in vitro and in vivo experiments. Our designed injectable hydrogel system provides a unique solution for enhancing the PTT.