Enhanced mild-temperature photothermal therapy by pyroptosis-boosted ATP deprivation with biodegradable nanoformulation.

Background: Mild-temperature photothermal therapy (mild PTT) is a safe and promising tumor therapeutic modality by alleviating the damage of healthy tissues around the tumor due to high temperature. However, its therapeutic efficiency is easily restricted by heat shock proteins (HSPs). Thus, exploitation of innovative approaches of inhibiting HSPs to enhance mild PTT efficiency is crucial for the clinical application of PTT.

Results: Herein, an innovative strategy is reported: pyroptosis-boosted mild PTT based on a Mn-gallate nanoformulation. The nanoformulation was constructed via the coordination of gallic acid (GA) and Mn. It shows an acid-activated degradation and releases the Mn and GA for up-regulation of reactive oxygen species (ROS), mitochondrial dysfunction and pyroptosis, which can result in cellular ATP deprivation via both the inhibiton of ATP generation and incresed ATP efflux. The reduction of ATP and accumulation of ROS provide a powerful approach for inhibiting the expression of HSPs, which enables the nanoformulation-mediated mild PTT.

Conclusions: Our in-vitro and in-vivo results demonstrate that this strategy of pyroptosis-assited PTT can achieve efficient mild PTT efficiency for osteosarcoma therapy.