Proximal Anchoring of Nanodrugs through In Situ Generated Radical Hooks with Boosted Autophagy and Immunotherapy.

Efficient retention of drugs at tumor sites was always desirable to maximize therapeutic functions, yet the main concern is the dynamic blood clearance induced fast removal from localized lesion. Herein, a tumor microenvironment activated covalently conjugation (self- and proximal conjugation) of tyramine modified Pt nanoclusters (PCMT NPs) was constructed by in situ produced radical hooks, leading to efficient accumulation of PCMT NPs at tumor sites. Such accumulation further aggravated the oxidative stress and provoked autophagy of tumor cells via activating the caspase-3 pathway mediated massive apoptosis, thereby stimulating immunogenic cell death (ICD). As verified by in vivo results, the PCMT NPs effectively suppressed primary and distant tumor growth (with an inhibition rate of 99%) while eliciting immunotherapeutic responses. As such, a new paradigm for boosting drug retention was provided, which enabled specific tumor treatment with synergistic therapeutic outcomes.