Thermosensitive hydrogel delivering a self-reinforced dual cascade nanoreactor for synergistic cuproptosis induction and immune microenvironment remodeling

The aggressive nature of oral squamous cell carcinoma (OSCC) and its highly immunosuppressive tumor microenvironment (TME) present significant challenges for effective treatment, urgently demanding advanced multi-modal therapeutic strategies. In this study, we designed a self-reinforced dual cascade nanoreactor (A@CuCD), delivered via a thermosensitive hydrogel, to execute a synergistic therapeutic strategy. The A@CuCD nanoreactors are co-assembled from copper nanoclusters (Cu NCs) and artesunate (ART) encapsulated within γ-cyclodextrin (γ-CD). This multifunctional engineering platform operates synergistically through a bifunctional system: it leverages the thermosensitive properties of the hydrogel to enable localized, on-demand retention and controlled release of A@CuCD at the tumor site, thereby efficiently inducing cuproptosis. The resulting immunogenic cell death (ICD) then further promotes cytotoxic T lymphocyte (CTL) infiltration and induces macrophage M1 polarization, consequently reversing immunosuppression and comprehensively remodeling the tumor microenvironment. Simultaneously, the intrinsic cholesterol-scavenging capability of γ-CD within A@CuCD not only enhances OSCC cell sensitivity to cuproptosis but also significantly downregulates programmed death-ligand 1 (PD-L1) expression by disrupting lipid raft structures, effectively suppressing tumor immune evasion. Utilizing single-cell RNA sequencing, we provide a systemic understanding of the hydrogel-mediated TME reprogramming process, elucidating the intricate interplay between cuproptosis and immune activation pathways. This engineered hydrogel platform effectively translates localized precise delivery into powerful systemic anti-tumor immunity, offering a highly promising and clinically translatable strategy for overcoming OSCC therapeutic resistance, conquering “cold” immune tumors, and achieving durable anti-tumor immunity.