Small-Sized and Stable 2D Metal-Organic Framework: A Functional Nanoplatform with Effective Photodynamic Therapy

The efficiency of photosensitizers in tumor photodynamic therapy (PDT) often compromises with their poor water solubility, low extinction coefficients, photobleaching, and dissatisfactory reactive oxygen species (ROS) generation efficiency. Herein, a nanoscale 2D metal−organic framework, Sm-H2TCPP nanosheets, was first synthesized from Sm3+-driven coordination behavior with porphyrin-derived (tetrakis (4-carboxyphenyl) porphyrin (H2TCPP)) for highly effective PDT of breast cancer. The prepared Sm-H2TCPP possessed nanoplate morphology with ultrathin thickness at sub-10 nm and ultrasmall plane size at sub-100 nm. Compared with free H2TCPP, the prominent ROS generation capacity of well-defined Sm-H2TCPP nanosheets is mainly attributed to the improved physicochemical property and the enhanced intersystem crossing from heavy Sm nodes. The significantly improved PDT efficacy of Sm-H2TCPP nanosheets was further testified in vitro and vivo based on MCF-7 breast cancer model. It is envisaged that the Sm-H2TCPP nanosheets will offer a new avenue for a new class of potential PDT agents.