Melanocytes are specialized cells found predominantly in the skin and eyes that form the pigment melanin, a polymer composed of several types of subunits formed from L-3,4dihydroxyphenylalanine. Melanin is deposited in subcellular particles called melanosomes. Cutaneous melanocytes originate from neural-crest progenitors that migrate to the skin during embryonic development. In the skin, melano...

For centuries skin pigmentation has played a major societal role, and genetic disorders of skin pigmentation have always evoked the curiosity of both laypersons and physicians. Normal skin pigmentation is a complex process that begins with the synthesis of melanin within the melanocytes, followed by its transfer to neighboring keratinocytes where it is translocated to the upper pole of the nucl...

INTRODUCTION It is simple fact that we judge one other, consciously or unconsciously, based in part on the aesthetic appearance of our outer integument, “skin”. As the human retina responds to a narrow bandwidth of the electromagnetic spectrum (so-called “visible light”, a nominal 400-700nm), the interaction of these wavelengths with skin, therefore, is of primary importance in our understandin...

SIAscopy – Spectrophotometric Intracutaneous Analysis – is a new optical skin imaging method in which computer reconstructed images reveal a number of aspects of skin histology, namely the concentration of epidermal melanin, the concentration of dermal blood, the thickness of the papillary dermis and, in pathological cases, the presence of dermal melanin. Due to its ability to provide a unique ...

The spatial distributions of melanin and hemoglobin in human skin are separated by independent-component analysis of a skin color image. The analysis is based on the skin color model with three assumptions: (1) Spatial variation of color in the skin is caused by two pigments, melanin and hemoglobin; (2) the quantities of the two pigments are mutually independent spatially; and (3) linearity hol...

Skin color in animals is richer than human beings and is determined by different types of pigments. Melanin is the key pigment responsible for the diverse pigmentation found in animal and human skin, hair, and eyes. Melanin pigment is synthesized by melanocytes and is consecutively transferred to adjacent keratinocytes; here, it acts as an internal sunscreen to defend from ultraviolet (UV) dama...

Melanocytes are highly specialised dendritic cells that transfer melanin to keratinocytes in subcellular lysosome-like organelles called melanosomes, where is synthesised and stored. Melanin a complex pigment provides colour photoprotection the skin, hair, eyes of mammals. The regulation melanogenesis includes various mechanisms factors including genetic, environmental, endocrine factors. Knowl...

Photoacoustic tomography is a hybrid modality based on optical absorption excitation and ultrasonic detection. It is sensitive to melanin, one of the primary absorbers in skin. For cells that do not naturally contain melanin, melanin production can be induced by introducing the gene for tyrosinase, the primary enzyme responsible for expression of melanin in melanogenic cells. Optical resolution...

Introduction Melanin is a dark pigment produced by about 10% of skin cells in the innermost layer of the epidermis (1). This compound is a heteropolymer of indole derivatives and is produced inside melanosomes through a series of oxidative reactions involving the amino acid tyrosine in the presence of the enzyme tyrosinase (Fig. 1). The type and amount of produced melanin in the melanosomes gen...