Synthesis of porphyrin-based 2D ytterbium metal organic frameworks for efficient photodynamic therapy

Photodynamic therapy (PDT), which relies on the photo-induced reactive oxygen species (ROS) to trigger tumor cells apoptosis, has attracted intense focus over the decades due to the minimum invasion, high-precision and controllable therapeutic processes. Tetra(4-carboxyphenyl) porphin (TCPP), as an effective PDT photosensitizer, can harness photons and generate singlet oxygen species (O-1(2)) upon illumination; however, poor solubility and low loading rate greatly limit its further use. Although TCPP-based metal-organic-frameworks (MOFs) has been proposed to address these concerns, the relatively large size still limits their biomedical applications. Therefore, in this study, TCPP molecules are coordinated with Yb3+, growing into 2D Yb-TCPP MOFs by a wet chemical method; the as-prepared Yb-TCPP MOFs are around 200 nm in size and possess high O-1(2) generation efficiency with low cytotoxicity. Due to TCPP is appeared as the organic frameworks of Yb-TCPP MOFs, the low loading rate problem is largely addressed; in addition, the absorbance of Yb-TCPP MOFs has been greatly expanded compared with free TCPP molecules due to the coordination with Yb3+, allowing the illumination at longer wavelength range, e.g. 655 nm, that possesses high penetration depth and low phototoxicity. Overall, we have prepared 2D Yb-TCPP MOFs suitable for the in vitro anticancer effect, revealing the potential of Yb-TCPP MOFs as the future anticancer agent.

Automated summary

In this study, 2D Yb-TCPP MOFs with a size of around 200 nm were synthesized using a wet chemical method. These MOFs exhibited high efficiency in generating singlet oxygen species (O-1(2)) and low cytotoxicity, showing promising potential as anticancer agents in vitro.