CHAPTER 7: Metallic Nanoparticles for Targeted Delivery of Photosensitisers for Photodynamic Therapy Check Access

This chapter describes the use of metallic nanoparticles, specifically gold and magnetic nanoparticles, as drug carriers for photodynamic therapy (PDT) of cancer. Metallic nanoparticles exhibit numerous properties that make them ideal candidates for PDT, including their size, their high surface area-to-volume ratio and their photochemical and photophysical characteristics. Metallic nanoparticles can be functionalised with a large number of photosensitiser molecules, which generate an increase in singlet oxygen and/or other reactive oxygen species. The size of the nanoparticles enables their internalisation into tumours through passive targeting via the enhanced permeability and retention effect, enabling the accumulation of nanoparticles in the cancerous tissue as compared to healthy tissue. The large surface area of metallic nanoparticles can be used to improve the selectivity towards tumour cells via the addition of chemical and/or biological ligands that are specific to the cell receptors that are overexpressed on the surfaces of the cancer cells (i.e., active targeting). Further, through surface functionalisation, metallic nanoparticles can be made water soluble, thereby enabling their direct systemic injection. The design and application of metallic nanoparticles for enhanced PDT are reviewed in this chapter.