Kurzfassung

versatile and biocompatible class of spin-labeled macromolecules was investigated by several methods of electron paramagnetic resonance (EPR), such as continuous wave (CW) EPR, electron spin echo-detected (ESE) EPR, and double electron-electron resonance (DEER). Further, their use for nuclear magnetic resonance (NMR) signal enhancement via dynamic nuclear polarization (DNP) was studied, which shows that they can be utilized for in vivo magnetic resonance imaging (MRI, DNP enhanced) and EPR...versatile and biocompatible class of spin-labeled macromolecules  was investigated by several methods of electron paramagnetic resonance (EPR), such as continuous wave (CW) EPR, electron spin echo-detected (ESE) EPR, and double electron-electron resonance (DEER). Further, their use for nuclear magnetic resonance (NMR) signal enhancement via dynamic nuclear polarization (DNP) was studied, which shows that they can be utilized for in vivo magnetic resonance imaging (MRI, DNP enhanced) and EPR imaging (EPRI). All presented heparin-polynitroxides show reasonably high 1H DNP enhancement factors up to E = 108, which is close to the maximum value that can be achieved
for nitroxide-based radicals. We could probe the dipolar couplings between the electron spins
and hence gain insight into the distance distributions of the spin labels that are rigidly attached
to the heparin backbone. The heparin-polynitroxides intrinsically feature high dipolar
electron spin-electron spin coupling frequencies. Together with the finding that the best
1H-signal enhancements are found in the low concentration region, this proves the influence of
the anisotropic (due to the attachment to the heparin molecules) electron spin distribution on
DNP in liquids at room temperature, which gives good signal enhancements at nominal concentrations
that are much lower than for freely tumbling radicals. The spin-labeled heparins
may also be suitable for an efficient hyperpolarization of 13C containing molecules and for
low temperature DNP measurements due to their broad range of dipolar coupling frequencies.
Furthermore, they can themselves be applied as hyperpolarized and functional substances that
target and bind to the endothelium and hundreds of different proteins.» weiterlesen» einklappen