Postsynthetic Ligand Exchange of Metal–Organic Framework for Photodynamic Therapy

Attributed to the large pore size and excellent stability, the metal–organic framework (MOF), NU-1000, which is formed by the coordination of Zr cluster and 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4TBAPy) ligand, has been widely studied in the catalysis research field; however, only a few reports about the biomedical application of NU-1000 could be found in the open literature. In this study, a functional ligand, tetrakis(4-carboxyphenyl)porphyrin (TCPP), was introduced into NU-1000 via a postsynthetic ligand exchange method and the resulting mixed ligand MOF has an excellent photodynamic effect. Finally, in vitro and in vivo assessment about the antitumor efficacy was investigated for the first time. It demonstrates the feasibility of TCPP-substituted NU-1000 to be used for photodynamic therapy and also provides an alternative approach to enrich the function of MOF for various applications via a postsynthetic method.