Porphyrin-Based Nanostructures for Cancer Theranostics:Chemistry, Fundamentals and Recent Advances

As heterocyclic macrocycle organic compounds, porphyrins can generate a rich platform of chemical behavior and characteristics conveniently utilized for multiple bioapplications, including bio-sensors, fluorescence tracking, and in vivo imaging. The conjugation of nanotechnology and porphyrins presents a promising approach to enhance the safety and effectiveness of porphyrin-based materials in phototherapy against cancer. Several nanoformulations, including organic and inorganic nanocarriers, porphyrin-laden nanoparticles, porphyrin-based amphiphilic molecules, supramolecular polymers, and porphyrin-based block copolymers, have been investigated to deliver porphyrins, which protect the pre-mature release of photosensitizer and provide tumor-selective and site-specific targeting. The monodisperse nanoparticles formed of biocompatible building block conjugates can be beneficially used to develop a multifunctional novel system utilized in optical imaging, positron emission tomography, photodynamic therapy, photothermal therapy, and other imaging modalities in one formulation. This topic is important because exploiting and knowing porphyrin-based nanostructures aids in detecting pathological damages that cannot readily be discovered by routine imaging or physical examination and thus, helps early diagnosis of cancer. This critical review will assess the basic knowledge and updated information for a broad audience of scientists, engineers, and newcomers related to the porphyrin-based nanostructures for cancer theranostics.