Nanoscale Two-Dimensional FeII- and CoII-Based Metal–Organic Frameworks of Porphyrin Ligand for the Photodynamic Therapy of Breast Cancer

The delivery of biocompatible reagents into cancer cells can elicit an anticancer effect by taking advantage of the unique characteristics of the tumor microenvironment (TME). In this work, we report that nanoscale two-dimensional Fe^II- and Co^II-based metal-organic frameworks (NMOFs) of porphyrin ligand meso-tetrakis (6-(hydroxymethyl) pyridin-3-yl) porphyrin (THPP) can catalyze the generation of hydroxyl radicals (•OH) and O₂ in the presence of H₂O₂ that is overexpressed in the TME. Photodynamic therapy consumes the generated O₂ to produce a singlet oxygen (¹O₂). Both •OH and ¹O₂ are reactive oxygen species (ROS) that inhibit cancer cell proliferation. The Fe^II- and Co^II-based NMOFs were non-toxic in the dark but cytotoxic when irradiated with 660 nm light. This preliminary work points to the potential of porphyrin-based ligands of transition metals as anticancer drugs by synergizing different therapeutic modalities.