Embracing defects and disorder in magnetic nanoparticles

TL;DR

This paper reviews how intentionally introducing defects in iron oxide magnetic nanoparticles can enhance their performance in biomedical applications like hyperthermia and imaging, challenging the traditional focus on defect-free particles.

Contribution

It highlights the emerging role of defect engineering in magnetic nanoparticles, providing a comprehensive overview and future perspectives for biomedical applications.

Findings

Defect-rich nanoparticles outperform defect-free ones in hyperthermia.

Defects improve magnetic particle imaging contrast.

Defect engineering offers new tuning methods for biomedical nanoparticles.

Abstract

Iron oxide nanoparticles have tremendous scientific and technological potential in a broad range of technologies, from energy applications to biomedicine. To improve their performance, single-crystalline and defect-free nanoparticles have thus far been aspired. However, in several recent studies defect-rich nanoparticles outperform their defect-free counterparts in magnetic hyperthermia and magnetic particle imaging. Here, an overview on the state-of-the-art of design and characterization of defects and resulting spin disorder in magnetic nanoparticles is presented with a focus on iron oxide nanoparticles. The beneficial impact of defects and disorder on intracellular magnetic hyperthermia performance of magnetic nanoparticles for drug delivery and cancer therapy is emphasized. Defect-engineering in iron oxide nanoparticles emerges to become an alternative approach to tailor their magnetic properties for biomedicine, as it is already common practice in established systems such as semiconductors and emerging fields including perovskite solar cells. Finally, perspectives and thoughts are given on how to deliberately induce defects in iron oxide nanoparticles and their potential implications for magnetic tracers to monitor cell therapy and immunotherapy by magnetic particle imaging.