A BismuthMetal–Organic Framework as a Contrast Agent for X‑rayComputed Tomography

A new bismuth metal–organic framework (MOF), bismuth-NU-901 (Bi-NU-901), featuring the scu topology and a pore with a diameter of ∼11 A, was solvothermally synthesized, and its use as an X-ray computed tomography (CT) contrast agent was tested. X-ray CT is a common diagnostic method used in the medical field. Inside the body, contrast media enhance the distinction between tissues and organs of similar density. Bi-NU-901 consists of eight connected Bi6 nodes and tetratopic 1,3,5,8-(p-benzoate)pyrene linkers (TBAPy). Numerous material characterization studies including powder X-ray diffraction (PXRD), scanning transmission electron microscopy (STEM), and DFT pore size distribution support the scu structure. Additionally, given the framework’s high density of nontoxic heavy atoms, Bi-NU-901 was evaluated as an X-ray computed tomography (CT) agent. Importantly, in vitro studies revealed this new bismuth MOF demonstrates ∼7 times better contrast intensity compared to a zirconium MOF featuring the same topology...