Bjrn Dollmann1, Andrei Kleschyov2, Kerstin Mnnemann1,3, Dariush Hinderberger1
1Max Planck Institute for Polymer Research, Mainz, Germany; 2Institute of Pharmacology, Johannes Gutenberg University, Mainz, Germany; 3Section of Medical Physics, Johannes Gutenberg University, Mainz, Germany
A versatile and biocompatible class of macromolecules with four different labeling degrees and positions is presented and investigated by DNP and three complementary EPR methods. DNP enhancement factors for these spin-labeled heparin molecules are measured as a function of microwave power and the projected maximum enhancement factors are compared. The macromolecule with an intermediate labeling degree shows the best DNP efficiency and 1H DNP enhancement factors up to -91 were observed. The EPR spectra let us conjecture that the spin-labeled heparin can be seen as a broad-band polarizing agent that might also be suitable for an efficient hyperpolarization of 13C.