Immunoinducible Carbon Dot-Incorporated Hydrogels as a Photothermal-Derived Antigen Depot to Trigger a Robust Antitumor Immune Response

Immunogenic tumor cell death (ICD) induced by photothermal therapy (PTT) fails to elicit a robust antitumor immune response partially due to its inherent immunosuppressive microenvironment and poor antigen presentation. To address these issues, we developed an immunoinducible carbon dot-incorporated hydrogel (iCD@Gel) through a dynamic covalent Schiff base reaction using mannose-modified aluminum-doped carbon dots (M/A-CDs) as a cross-linking agent. The M/A-CDs possessed superior photothermal conversion efficiency and served as nanocarriers to load cytosine–phosphate–guanine oligodeoxynucleotides (CpG ODNs) for inducing the maturation of dendritic cells (DCs) via mannose receptor-mediated targeting delivery. Upon intratumoral injection, the as-prepared iCD@Gel induced ICD, and damage-associated molecular patterns (DAMPs) were released via photothermal ablation under 808 nm NIR irradiation. Subsequently, the iCD@Gel synergized with the DAMPs to significantly promote the maturation and antigen cross-presentation ability of DCs. This work provides a promising strategy to develop carbon dot-based therapeutic hydrogels for photothermal therapy and immune activation.