Hybrid polarizing solids for pure hyperpolarized liquids through dissolution dynamic nuclear polarization

Area of Science:

• Magnetic Resonance Spectroscopy (MRS)
• Magnetic Resonance Imaging (MRI)
• Dynamic Nuclear Polarization (DNP)

Background:

• Dissolution dynamic nuclear polarization (D-DNP) enhances nuclear spin polarization for MRS and MRI.
• Current D-DNP methods often use polarizing agents (PAs) and glassing agents, which can contaminate samples and reduce hyperpolarization.
• Concerns exist regarding PA and glassing agent presence for in vivo applications.

Purpose of the Study:

• To develop a novel D-DNP method that eliminates the need for PAs and glassing agents in the final hyperpolarized solution.
• To demonstrate the efficiency and applicability of this new approach for various substrates.

Main Methods:

• Utilized hybrid polarizing solids (HYPSOs) containing 2,2,6,6-tetramethyl-piperidine-1-oxyl radicals within a mesoporous silica matrix.
• Employed incipient wetness impregnation to load substrates into the HYPSO pores.
• Performed D-DNP at low temperatures, followed by rapid dissolution and filtration to separate the pure substrate.

Main Results:

• Achieved efficient hyperpolarization using HYPSOs without glass-forming agents.
• Demonstrated applicability to a broad range of substrates, including peptides and metabolites.
• Successfully isolated pure hyperpolarized solutions free from paramagnetic or other contaminants via simple filtration.

Conclusions:

• HYPSOs offer an effective strategy for D-DNP, yielding pure hyperpolarized solutions suitable for in vivo MRS and MRI.
• This filtration-based separation method overcomes limitations associated with traditional D-DNP techniques.
• The developed approach enhances the safety and utility of hyperpolarized agents for biomedical applications.