Mangafodipir

Mangafodipir (sold under the brand name Teslascan as mangafodipir trisodium) is a contrast agent delivered intravenously to enhance contrast in magnetic resonance imaging (MRI) of the liver. It has two parts, paramagnetic manganese (II) ions and the chelating agent fodipir (dipyridoxyl diphosphate, DPDP). Normal liver tissue absorbs the manganese more than abnormal or cancerous tissue. The manganese shortens the longitudinal relaxation time (T1), making the normal tissue appear brighter in MRIs. This enhanced contrast allows lesions to be more easily identified.

Teslascan was withdrawn from the US market in 2003 and the European market in 2012.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) participate in pathological tissue damage. Mitochondrial manganese superoxide dismutase (MnSOD) normally keeps ROS and RNS in check. During development of mangafodipir as an MRI contrast agent, it was discovered that it possessed MnSOD mimetic activity. Mangafodipir has been tested as a chemotherapy adjunct in cancer patients and as an adjunct to percutaneous coronary intervention in patients with myocardial infarctions, with promising results. Whereas MRI contrast depends on release of Mn²⁺, the MnSOD mimetic activity depends on Mn²⁺ that remains bound to DPDP. Calmangafodipir [Ca₄Mn(DPDP)₅] (brand name PledOx) is stabilized with respect to Mn²⁺ and has improved therapeutic activity. Calmangafodipir is being explored as a chemotherapy adjunct in cancer patients.