Nanomodulators Capable of Timely Scavenging ROS for Inflammation and Prognosis Control Following Photothermal Tumor Therapy

Despite the accuracy advantages of photothermal therapy (PTT), heat stress-initiated free radicals and damage-activated immune cells form a malignant positive feedback cycle following light irradiation. Herein, a 2D allomelanin nanomodulator with perpendicularly oriented oligomer planes is prepared by the guidance of DNA to achieve timely scavenging of reactive oxygen species (ROS) for inflammation and prognosis control following PTT. A large exposure degree of phenol groups and the effective transfer of delocalized electrons result in ultra-fast redox reactions that can be boosted by a self-amplifying process through structure disintegration. Compared with conventional photothermal agents, the nanodisks reduce the accumulation of ROS during PTT by 25-fold, downregulate the proinflammatory factors, and adjust inflammation levels to baseline. Thereby, successful modulation of M2-type macrophages in paratumor tissues significantly prevents burn wound progression and accelerates tissue repair, while well-controlled neutrophil extracellular traps and largely recruited CD4(+)/CD8(+) T cells (1.6-3.2-fold) in the ablation site suppress the relapse of distant tumors. The study provides a useful inspiration on rationally modulating redox active nanostructures to address prognosis issues following PTT.