A Self-Adaptive Rhodium(I) Complex-Based Nanoplatform with Type II Immunogenic Cell Death for Near-Infrared Phosphorescence Imaging and Cancer Immunotherapy.

Despite immunogenic cell death (ICD) has garnered significant attention in cancer therapy, achieving precise in vivo immunity activation and simultaneous visualization of immunotherapy processes remain significant challenges due to the difficulties in facile integration of multifunctionalities in a single nanomedicine. For this purpose, herein a self-adaptive rhodium(I) complex-based nanoplatform driven by metallophilic interactions is reported not only for near-infrared (NIR) imaging-guided cancer immunotherapy, but also as the first example of a rhodium(I)-based ICD inducer. Specifically, this nanoplatform enables high tumor enrichment by utilizing homologous targeting capability camouflaged by cancer cell membranes and facilitates enhanced in vivo NIR phosphorescence imaging. The subsequent uptake of this nanoplatform by tumor cells via endocytosis releases the antitumor rhodium(I) complex monomer, which can target directly the endoplasmic reticulum and induce a more effective type II ICD for enhanced dendritic cell maturation and cytotoxic T lymphocyte infiltration, and ultimately lead to long-acting antitumor immunity. Notably, the self-adaptive functional switch strongly supports the NIR phosphorescence imaging and cancer immunotherapy of this platform, which displays a remarkable inhibitory effect with a tumor inhibition rate of 91.2%. This study develops a facile yet robust approach toward an "all-in-one" metal-based ICD agent with visualization properties for monitoring immunotherapy.