Carbon-based nanomaterials in photodynamic therapy of cancer

Photodynamic Therapy (PDT) is an alternative cancer treatment based on the synergistic action of photosensitizer (PS), oxygen, and light exposure in a suitable wavelength range. The increased need for PSs with high selectivity, non-toxicity, and the ability to generate reactive oxygen species (ROS) led to the introduction of nanotechnology to PDT research. Carbon-based nanomaterials, including fullerenes, carbon nanotubes, graphene oxide, and carbon-based dots, have been used as photodynamic agents alone or in combination with commonly used PSs due to their superb optoelectronic features, biocompatibility, size, and surface properties. The present review addresses basic principles of PDT, along with recent trends and challenges. Furthermore, carbon-based nanomaterials are discussed with an emphasis on vital features for a potential photosensitizing agent. The main focus of this article is the application of carbon-based nanomaterials in PDT, presenting both in vitro and in vivo studies, as well as highlighting current limitations and future directions.