| Autor: |
Shen B; Chemistry Graduate Group, University of California, One Shields Ave, Davis, California 95616, United States., Gao M; Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, United States., Franco FC Jr; Chemistry Department, De La Salle University, 2401 Taft Avenue, 0922 Manila, Philippines., Kapre R; Department of Biomedical Engineering, University of California, One Shields Avenue, Davis, California 95616, United States., Zhou J; Chemistry Graduate Group, University of California, One Shields Ave, Davis, California 95616, United States., Li X; Department of Biomedical Engineering, University of California, One Shields Avenue, Davis, California 95616, United States., Garcia J; Chemistry Department, De La Salle University, 2401 Taft Avenue, 0922 Manila, Philippines., Shaw JT; Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, United States., Louie AY; Chemistry Graduate Group, University of California, One Shields Ave, Davis, California 95616, United States.; Department of Biomedical Engineering, University of California, One Shields Avenue, Davis, California 95616, United States. |
| Abstrakt: |
Light-activated sensors are of great interest for biological applications but are limited by the depth of penetration of light. We have been interested in transducing light activation to a magnetic signal that can be detected through noninvasive imaging by magnetic resonance imaging (MRI). We have previously developed agents incorporating spiropyran derivatives as the sensing moiety and characterized features that influence photoswitching; however, we found the MRI response to be unpredictable. In this work, we delve deeper into the potential mechanisms for the observed MRI responses in an effort to better understand the structural effects on controlling magnetic properties. A series of light-activatable MRI contrast agents were synthesized and characterized to assess the effect of spiropyran positioning on contrast agent functions and properties. These compounds are based on the same spiropyran skeleton, also named 1',3',3'-trimethyl-6-nitrospiro[chromene-2,2-indoline], which is linked with an MRI contrast agent, gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7-triacetate (DO3A). We investigated the photo-to-magnetic conversion properties of these novel compounds by adjusting linker lengths over a range from three to seven methylene groups. The primary results indicated that the contrast agent with a five-carbon linker ( 25 ) showed the highest light-sensing ability after irradiation with visible light. The results will aid in the design of future spiropyran-based MRI sensors. |
