Bimetallic Fe, Ru-doped Zn-Centered Organic Framework Mesoporous Carbon for Single-Wavelength Near-Infrared-Induced Photothermal/Photodynamic Synergistic Therapy.

Abstract

Single-wavelength synergistic photothermal/photodynamic therapy (PTT/PDT) is gradually emerging in cancer treatment, with the key limitation being the photosensitizer. In this work, a metal-organic framework-derived mesoporous carbon with zinc centers and doped with iron and ruthenium, exhibiting porphyrin-like properties (denoted as Fe₅₀-Ru_y-ZIF₉₀₀), was successfully synthesized via a green, simple, and mild hydrothermal reaction. The effects of various Fe:Ru doping ratios on the morphology, structure, and PTT/PDT of Fe₅₀-Ru_y-ZIF₉₀₀ were studied. We found that bimetallic doping significantly improved both the PTT and PDT performance of the materials. Especially for Fe₅₀-Ru₁₀-ZIF, it demonstrated the best PTT/PDT performance under single-wavelength near-infrared (808 nm) light irradiation in a hydrophilic environment. Its photothermal conversion efficiency (η) can be as high as 57.66%, and the singlet oxygen (¹O₂) quantum yield (Φ) is about 0.0053, comparable to that of indocyanine green (ICG). This enhancement may be attributed to the synergistic effect between homologous elements of the same family. In addition, under single-wavelength near-infrared laser irradiation, Fe₅₀-Ru₁₀-ZIF₉₀₀ can generate a substantial amount of ¹O₂ in living tumor cells and synergistically induce extensive necrosis/apoptosis of tumor cells. All of these findings indicate that Fe₅₀-Ru₁₀-ZIF₉₀₀ can serve as an excellent photosensitizer, bringing greater feasibility to the realization of single-wavelength dual-mode PTT/PDT treatment.