Accelerated ¹⁹F·MRI Detection of Matrix Metalloproteinase-2/-9 through Responsive Deactivation of Paramagnetic Relaxation Enhancement

Figure 2

¹⁹F·NMR spectroscopy of MMP-mediated biosensor cleavage at 14.1 Tesla. (a) ¹⁹F·NMR lineshape of 0.1 mM-specific MMP-2/-9 probe as a function of time at 298 K. After MMP-9 was added at t = 0, the NMR signal of the probe showed an increase in the amplitude and sharpening of the peak. (b) Time course of NMR signal intensity (amplitude) of the specific MMP-2/-9 probe (0.1 mM) as a function of time after MMP incubation under different conditions: at 298 K in pure D₂O, at 298 K in v/v 9 : 1 H₂O/D₂O, and at 310 K in v/v 9 : 1 H₂O/D₂O. The fastest reaction rate was observed at physiological temperatures (310 K). (c) Time course of NMR signal intensity (amplitude) of the broad-range probe with MMP-9 added at t = 0. For the broad-range probe, the reaction rate was fastest at room temperature (298 K), in contrast to the optimal conditions for the specific MMP-2/-9 probe.

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