Applications of Hyperpolarized Magnetic Resonance Spectroscopy with Functional Nanomaterials and Small Organic Molecules

Abstract

Applications of Hyperpolarized Magnetic Resonance Spectroscopy with Functional Nanomaterials and Small Organic Molecules Quy Son Luu Department of Bionano Technology The Graduate School Hanyang University Hyperpolarized magnetic resonance spectroscopy (MRS) has emerged as a powerful technique in biomedical imaging and molecular sensing, offering enhanced sensitivity and signal strength compared to conventional MRS methods. The integration of nanomaterials and small organic molecules into hyperpolarization strategies has sparked considerable interest, leveraging their unique properties to overcome limitations associated with signal decay and low detection thresholds. This dissertation explores recent advancements in employing nanomaterials, such as hyperpolarization agents, and small organic molecules as potential imaging probes for hyperpolarized MRS applications. Various nanomaterial platforms, including nanoparticles, carbon-based and silicon-based materials, and hyperpolarizing agents, have been engineered to enhance polarization efficiency and prolong hyperpolarization lifetimes. Additionally, the utilization of small organic molecules with tailored chemical structures has exhibited promising capabilities in achieving hyperpolarization and facilitating targeted molecular imaging and sensing. The synergistic combination of nanomaterials and small organic molecules holds immense potential in revolutionizing hyperpolarized MRS techniques, enabling novel applications in diverse fields, including biomedical imaging, materials science, and drug development. This comprehensive overview underscores the recent progress, challenges, and future prospects of utilizing nanomaterials and small organic molecules in advancing hyperpolarized MRS methodologies for high-resolution imaging and sensitive molecular detection. In this dissertation, the solid-state dynamic nuclear polarization (DNP) and signal amplification by reversible exchange (SABRE) are used to obtain the signal enhancement of nanoparticles and small molecules with various applications. The initial project employed diverse radical-embedded silica nanoparticles, including shell, core, and uniformly embedded particles, to explore the potential of a 29Si MRI imaging probe without relying on an external radical source. These nanoparticles could self-polarize, with the homogeneously embedded ones exhibiting the most significant enhancement in the 29Si NMR signal. Alongside the solid-state DNP technique, the SABRE method hyperpolarizes small organic molecules, specifically nicotinamide derivatives. The experiments were conducted using a home-built parahydrogen system and detected through a high-field MR spectrometer (400 MHz). The enhancement in signal for these substances was attributed to factors such as magnetic field, dissociation rate, and longitudinal relaxation time. Additionally, the dissertation explored functional nanomaterials for environmental applications. Three types of iron-carbon nanoparticles (multicore, core@shell, and covalent bonding) were investigated for their efficiency in adsorbing organic contaminants. The covalent bonding structure demonstrated the highest adsorption capacity and recycling efficiency. The project delved into the mechanisms underlying the adsorption behavior of these nanomaterials.