Klaus Kruttwig1, Diego R. Yankelevich2, Chantal Brueggemann3, Chuqiao Tu1, Erica Andreozzi1, Noelle L'Etoile3, Andr Knoesen2, Angelique Y. Louie1
1Department of Biomedical Engineering, University of California Davis, Davis, CA, United States; 2Department of Electrical and Computer Engineering, University of California Davis, Davis, CA, United States; 3Center for Neuroscience, University of California Davis, Davis, CA, United States
The work performed here describes as a long term goal a method to noninvasively map gene expression in deep tissues in vivo by developing magnetic resonance contrast agents (MRI CA) that are responsive to commonly employed luminescent biomarker systems. Photoswitchable spiropyran has been conjugated to the crowned ring system DO3A complexed with the lanthanide ion Gadolinium(III). This leads to a photoresponsive MRI CA that displays an increased spin-lattice relaxation time (T1) upon visible light stimulation. The photo response of this contrast agent to weak light illumination using light emitting diodes was investigated, simulating the emission spectra from Gaussia princeps luciferase.