BODIPY-containing nanoscale metal-organic frameworks as contrast agents for computed tomography

Nanoscale metal-organic frameworks (NMOFs) maintaining the features of both their bulk MOF analogue and nanoparticle formulation have recently emerged as promising platforms for biomedical imaging and drug delivery. In this work, NMOFs were developed and used as computed tomography (CT) imaging agents. The biocompatibility and CT imaging of iodine-boron-dipyrromethene (BODIPY)-containing MOF nanocrystals, named UiO-PDT, have been studied well in vitro and in vivo. Systemic investigations about the biodegradability and in vivo safety were carried out in living animals, and there is no obvious severe acute or sub-acute toxicity even at a very high injected dosage (100 mg kg^-1). In vivo CT imaging results indicate that the as-synthesized UiO-PDT nanocrystals can preferentially accumulate in the tumor sites, not in the surrounding connective tissues and organs for rats bearing hepatomas, and give the best imaging performance after intravenous administration for about 24 h. The aforementioned findings suggest that such nanocrystals may have potential for use as CT contrast agents.