Biomineralized hybrid nanodots for tumor therapy via NIR-II fluorescence and photothermal imaging

Chemodynamic therapy (CDT) is an emerging and promising therapeutic strategy that suppresses tumor growth by catalytically converting intracellular hydrogen peroxide (H₂O₂) into highly-reactive hydroxyl radicals (•OH). However, the inherent substrate of H₂O₂ is relatively insufficient to achieve desirable CDT efficacy. Therefore, searching for integrated therapeutic methods with synergistic therapeutic modality is especially vital to augment therapeutic outcomes. Herein, we reported nanodot- Cu_xMn_yS_z @BSA@ICG (denoted as CMS@B@I) and bovine serum albumin (BSA)-based biomineralization Cu_xMn_yS_z (CMS) loaded with photodynamic agent-indocyanine green (ICG). CMS@B@I converts endogenous hydrogen peroxide (H₂O₂) into highly active hydroxyl radical (•OH) via Fenton reaction, and effectively produces reactive oxygen species (ROS) after being exposed to 808 nm laser irradiation, attributable to the excellent photodynamic agent-ICG. This results in eliciting a ROS storm. Additionally, CMS@B@I exhibits a superior photothermal effect under NIR-II 1064 nm laser irradiation to enhance tumor CDT efficacy. The NIR-II fluorescence imaging agent of ICG and the excellent photothermal effect of CMS@B@I are highly beneficial to NIR-II fluorescence and infrared thermal imaging, respectively, resulting in tracing the fate of CMS@B@I. This study attempts to design a bimodal imaging-guided and photothermal-enhanced CDT nanoagent for augmenting tumor catalytic therapy.