Biomimetic Platinum Nanozyme Immobilized on 2D Metal–Organic Frameworks for Mitochondrion-Targeting and Oxygen Self-Supply Photodynamic Therapy

Photodynamic Therapy (PDT) as a noninvasive therapy mode has attracted considerable attention in the field of oncotherapy. However, the PDT efficacy is restricted either by tumor hypoxia environment or the inherent properties of photosensitizers (PSs) including bad water solution, photobleaching, and easy aggregation. Herein, we designed and synthesized a new 2D metal-organic framework Sm-TCPP nanosheets by assembling transition metal ion (Sm3+) and PSs (TCPP), on which the catalase (CAT)-mimicking platinum nanozyme were then in situ grown for sufficient oxygen supply during PDT. The prepared Sm-TCPP with nanoplate morphology (~100 nm in diameter) and ultrathin thickness (<10 nm) showed significantly enhanced 1O2 generation capacity due to the improved physicochemical property and the enhanced intersystem crossing from heavy Sm nodes. More importantly, the CAT-mimicking Pt nanozyme on the Sm-TCPP nanosheets could effectively convert over-expressed H2O2 in tumor microenvironment (TME) into O2 to relieve tu...