Multifunctional Dual-Ligand MOF for Capture, Imaging, and Photodynamic Clearance of Circulating Tumor Cells

Circulating tumor cells (CTCs), as important markers for liquid biopsy, are of great significance for the early diagnosis of cancer and evaluation of postoperative efficacy. Currently, it is a challenge to capture rare CTCs in the complex environment of peripheral blood. In this study, a multifunctional dual-ligand MOF (MD-MOF) was prepared with porphyrin as the first ligand and a boronic acid group as the second ligand. In the MD-MOF, the porphyrin ligand can image the captured CTCs using its own fluorescence properties and further act as a photosensitizer to generate cytotoxic reactive oxygen species under light irradiation, killing the captured CTCs. The boronic acid group used to bond to the glycosylation site of avidin and self-assembled with the biotinylated aptamer to alleviate the inactivation of aptamers caused by interchain entanglement. MD-MOF can specifically capture MCF-7 cells with a capture efficiency as high as 93%. Even at an extremely low cell concentration (10 cells mL^-1), the capture efficiency can still reach 76%. The captured cells can be eliminated within 5 min by laser irradiation or can be released without damage through a fructose competitive reaction. The multifunctional material integrated CTC capture, imaging, and photodynamic therapy, exploring the application potential in CTC capture.