Biomedical overview of melanin.1.Updating melanin biology and chemistry,physico-chemical properties,melanoma tumors,and photothermal therapy

Melanins(eumelanin,pheomelanin,and allomelanin)represent a very,if not themost,important group of biological pigments.Their biological roles are multiple,from photoprotection to antioxidant activity,heavy metal disposal or the myriad uses of color in organisms across all Phyla.In the first part of this review,eumelanin biology and some chemical aspects will be presented,as well as key physico-chemical features that make this biological pigment so interesting.The principal characteristics of the melanocyte,the melanin-synthesizing cell in mammals,will also be introduced.Transformed melanocytes are the cause of one of the most devastating known cancers:the malignant melanoma.Epidemiology and molecular signaling aspects will be presented next,as well as the principal advances in promising oncotherapies designed and applied for the treatment of melanoma.In particular,on account of the photo-physical properties of melanin,special details will be provided regarding the use of photothermal therapy for melanoma treatment.