Chapter 7: Porphyrin Nanoparticles for Cancer Imaging and Phototherapy

Phototherapies including photodynamic therapy (PDT) and photothermal therapy (PTT) are extensively investigated as potent alternative therapeutic modalities for cancer treatment. Porphyrins, the nature existed chromophores, have a rich history of phototherapy, especially for PDT. Paramount efforts have been involved in the development of porphyrin-based photosensitizers to enhance therapeutic efficacy and decrease toxicity. The union of porphyrin and nanotechnology offers new perspective to improve the safety and efficacy of porphyrin-based PDT. Various nanovectors, both organic and inorganic, have been investigated on porphyrin delivery for high payload photosensitizers, protection from pre-mature release and tumor-selective targeting. Most recently, the development of porphyrin-based “one-for-all” nanoparticles has opened up a brand new avenue for rational design of multifunctional nanoconstruct with multimodal imaging and therapeutic capabilities. When porphyrin is utilized as built-in elements to form the nanostructure, the high densely packed or orderedly aggregated porphyrin produce new photonic properties beyond porphyrin monomer, such as photoacoustic and photothermal properties. Marching on the frontline of cancer theranostics, porphyrin nanotechnology is turning one of nature's most fascinating molecules into powerful imaging and therapeutic platforms.