A new class of easily synthesized manganese contrast agents for liver MRI

This work investigated the performance of a novel class of Mn(II) T1 contrast agents made from a commercially available chelator with various lipophilic targeting moieties added to promote uptake through the human derived OATP1B1 and OATP1B3 transporters. Agent performance was assessed in vitro using cells engineered to express the human OATPs, and in vivo by assessing liver uptake in mice where other OATP isoforms are present. In vitro measurements suggested targeting of agents to human OATPs where in vivo imaging revealed strong contrast enhancement in murine livers, with no evident toxicity at a 0.1 mmol/kg dose.