Photoinduced in Vivo Magnetic Resonance Imaging (MRI) with Rapid CO Release from an MnCO‐Protein Needle Composite

Abstract

Construction of an artificial protein needle (PN), which includes the membrane puncturing needle domain of bacteriophage T4 conjugated to Mn carbonyl (MnCO) complexes, is reported. The responsiveness to visible light of the MnCO complex makes it useful as a photoinduced in vivo magnetic resonance imaging contrast reagent (MRI CR), because the PN carrier has the potential to deliver the MnCO complex into mouse tumors with retention of coordination structure within the in vivo environment. Moreover, the composite has higher relaxivity and longer circulation as an MRI CR than the corresponding MnCO complex. These results demonstrate construction of a responsive in vivo MRI CR by using an artificial metalloprotein.

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

“…The group of Ueno developed a construct containing an artificial protein needle by conjugating the membrane puncturing needle domain of bacteriophage T4 to the Mn I carbonyl photoCORM complex 247 (Table 16) via a maleimide thiol linkage. 1165 This system was used as an in vivo magnetic-resonance-imaging contrast reagent. Allosteric regulation of CO release was demonstrated in complex 248a (Table 16), 1166 in which the phenolic substituent of the terpyridyl ligand responds to fluoride ions by undergoing deprotonation, leading to allosteric activation of CO release; the deprotonated complex released CO approximately 1 order of magnitude more efficiently than its neutral form.…”

“…These materials combine a Mn I tricarbonyl bipyridyl complex 246 (Table ) with a highly robust Zr IV -based MOF. The group of Ueno developed a construct containing an artificial protein needle by conjugating the membrane puncturing needle domain of bacteriophage T4 to the Mn I carbonyl photoCORM complex 247 (Table ) via a maleimide thiol linkage . This system was used as an in vivo magnetic-resonance-imaging contrast reagent.…”