In-vivo magnetic resonance imaging of hyperpolarized silicon particles

TL;DR

This paper demonstrates in-vivo MRI imaging of hyperpolarized silicon particles, showcasing their potential for biomedical imaging due to their biocompatibility, long polarization times, and functionalization capabilities.

Contribution

It introduces a novel MRI technique for direct imaging of hyperpolarized silicon particles in vivo, leveraging silicon's unique physical properties.

Findings

Successful in-vivo imaging of hyperpolarized 29Si in silicon microparticles

Potential for imaging at sub-picomolar concentrations

Biocompatibility and functionalization of silicon particles confirmed

Abstract

Silicon-based micro and nanoparticles have gained popularity in a wide range of biomedical applications due to their biocompatibility and biodegradability in-vivo, as well as a flexible surface chemistry, which allows drug loading, functionalization and targeting. Here we report direct in-vivo imaging of hyperpolarized 29Si nuclei in silicon microparticles by MRI. Natural physical properties of silicon provide surface electronic states for dynamic nuclear polarization (DNP), extremely long depolarization times, insensitivity to the in-vivo environment or particle tumbling, and surfaces favorable for functionalization. Potential applications to gastrointestinal, intravascular, and tumor perfusion imaging at sub-picomolar concentrations are presented. These results demonstrate a new background-free imaging modality applicable to a range of inexpensive, readily available, and biocompatible Si particles.