Melanin and melanoma tumors are two fields of increasing interest in biomedical research.
Melanins are ubiquitous biopigments with adaptive value and multiple functions, and occur in the
malignant melanoma. Although several chemical structures have been proposed for eumelanin,
molecular modeling and orbitals indicate that a planar or spiral benzoquinone-porphycene polymer
would be the model that better explains the broad-band light and ultrasound absorption, electric
conductivity, and graphite-like organization shown by X-ray crystallography and electron microscopy.
Lysosomes and melanosomes are selectively labeled by vital probes, and melanin also binds to
metal cations, colorants, and drugs, with important consequences in pharmacology, pathology,
and melanoma therapy. In addition to traditional and recent oncologic treatments, photodynamic,
photothermal, and ultrasound protocols represent novel modalities for melanoma therapy. Since
eumelanin is practically the ideal photothermal and ultrasound sensitizer, the vibrational decay
from photo-excited electrons after NIR irradiation, or the electrochemical production of ROS and
radicals after ultrasound absorption, induce an efficient heating or oxidative response, resulting in
the damage and death of tumor cells. This allows repetitive treatments due to the remaining melanin
contained in tumoral melanophages. Given that evolution and prognosis of the advanced melanoma
is still a concern, new biophysical procedures based on melanin properties can now be developed
and applie
