CHAPTER 3: Applications of Magnetic Nanoparticles in Multi-modal Imaging

A range of nanoparticles, made of different types of biomaterials, have been developed as carriers to deliver drugs or imaging probes for therapeutic or diagnostic purposes respectively. These can offer better delivery, increase drug loading, improve stability and even achieve desired targeting by means of chemical modifications including incorporation with specific targeting ligands. The more efficient the delivery, the lower the dosage required, which can greatly reduce systemic side effects from the drugs themselves. Magnetic nanoparticles (MNPs), have been utilised as imaging probes due to their intrinsic magnetic properties and metallic nature. When incorporated with therapeutic agents, they are specially designed to concentrate at the target site with the aid of magnetic force, resulting in dual theranostic function (therapy and diagnosis). MRI with MNPs is one imaging application that is well studied and has been used in the clinic with high resolution. Moreover, MNPs have provided a new avenue in the field of biomedical imaging as tools for multi-modal imaging. Recent developments have shown promise in combining MRI with other imaging approaches as well. The first part of this chapter contains the general introduction of nanoparticles and MNPs. The second part focuses on the applications of MNPs in biomedical imaging, including the utilisation of MNPs in various imaging techniques and the vast recent developments in multi-modal imaging. Finally, the applications and challenges of MNPs in drug delivery, particularly for tumour targeting, are addressed.