TY - JOUR
T1 - Modulation of T2 relaxation time by light-induced, reversible aggregation of magnetic nanoparticles
AU - Osborne, Elizabeth A.
AU - Jarrett, Benjamin R.
AU - Tu, Chuqiao
AU - Louie, Angelique Y.
PY - 2010/5/5
Y1 - 2010/5/5
N2 - A reversible T2 contrast agent consisting of cross-linked anionic dextran coated iron oxide nanoparticles covalently coupled to a light-sensitive spiropyran (SP)/merocyanine (MC) motif was synthesized and characterized. In aqueous solution, light induced isomerization of the molecular switches between the hydrophobic SP isomer and hydrophilic MC isomer directs the aggregation and dispersion of the nanoparticles, respectively. When in the dark, where the MC form dominates, the probe has a T2 relaxation time of 37.09 ms (60 MHz, 37 °C) and two size populations at 70 and 540 nm. After irradiation with visible light, the T2 relaxation time is shortened 33.7%, and the size correspondingly shifts to a single population at 520 nm upon aggregation. This smart T2 agent provides the advantage of reversibility which may enable dynamic monitoring with MRI. In addition, the light responsiveness of this agent suggests the potential to employ them as MRI gene reporters for the luciferase expression system.
AB - A reversible T2 contrast agent consisting of cross-linked anionic dextran coated iron oxide nanoparticles covalently coupled to a light-sensitive spiropyran (SP)/merocyanine (MC) motif was synthesized and characterized. In aqueous solution, light induced isomerization of the molecular switches between the hydrophobic SP isomer and hydrophilic MC isomer directs the aggregation and dispersion of the nanoparticles, respectively. When in the dark, where the MC form dominates, the probe has a T2 relaxation time of 37.09 ms (60 MHz, 37 °C) and two size populations at 70 and 540 nm. After irradiation with visible light, the T2 relaxation time is shortened 33.7%, and the size correspondingly shifts to a single population at 520 nm upon aggregation. This smart T2 agent provides the advantage of reversibility which may enable dynamic monitoring with MRI. In addition, the light responsiveness of this agent suggests the potential to employ them as MRI gene reporters for the luciferase expression system.
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U2 - 10.1021/ja100254m
DO - 10.1021/ja100254m
M3 - Article
C2 - 20373802
AN - SCOPUS:77951698658
VL - 132
SP - 5934
EP - 5935
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 17
ER -