Melanin is a type of pigment that gives color to the hair, skin, and eyes in humans and animals. In addition to providing pigmentation for the cells, Eumelanin also absorbs harmful UV rays and protects against cellular damage from UV light exposure. But that's not all! There are four types of Melanin in the Human body making melanin by the gram more expensive than platinum, Gold or Diamonds!
Black skin has a natural sun protection barrier equal to sunscreen between 13.4 - 20 SPF because it contains more melanin (the stuff that gives your skin its color). White skin has only a quarter of that protection against the rays of the sun. Its protective barrier amounts to an average SPF of 3.3.
This advantage means Black skin shows signs of sun damage more slowly, but more melanin also means there’s a higher chance of developing uneven spots that may be a shade darker or lighter than the skin around it.
Collagen is the protein that causes Black skin to age slower. But, lots of collagen leads to more opportunity for scars to form. There are similarities in skin, but Black skin is physiologically different to white skin in a few ways. Everyone – whether you are Black, white or of mixed-race heritage – has melanocyte cells, living at the very bottom layer of your skin called the stratum basale.
Within these melanocyte cells are the melanosomes, the bits that contain the pigment called melanin. In the bottom layer of your skin, the cells that contain melanin are actually transparent with no color at all. As they migrate through the layers of skin, they then take on their distinctive color. There are two different types of melanin pigment produced by the melanocytes: eumelanin – a dark brown pigment, and pheomelanin – a red or yellow tint.
Black people and those with darker skin tones have more eumelanin, hence our different shades of brown skin color, whereas white and lighter skin tones have pheomelanin. Eumelanin is a UV-absorbing agent and is able to protect the skin against the effects of UV light on the skin's surface. It also offers protection against UVB and blue light. Eumelanin protects the skin from UV light, whereas pheomelanin does not.
The pigment or melanocyte cells have tentacles, just like an octopus, that extend to other layers of skin to make sure melanin pigment is evenly distributed throughout the skin, giving us all our unique individual skin colors. Black skin produces twice as much melanin as white skin. These cells that house the melanin also age more slowly in darker skin tones. White and lighter skin tones, conversely, have smaller melanosomes, which are clustered together and rarely found in the upper layers of the epidermis. The melanosomes in white skin are stimulated by UV radiation from the sun, hence why white skin goes Red or Tan (a light brown) in the sun.
In the middle of this spectrum sits most people of Asian descent, who also have large melanosomes that are found individually as well as grouped together. Together, the combination of increased melanin and its distribution in the skin gives Black skin some protection from premature ageing caused by UV radiation from the sun. Melanin is produced by melanocytes and synthesized by tyrosine. The first are cells found in the hair follicles of the epidermis. The second are amino acids that are also present in skin, hair and eye coloring pigments.
Once produced, melanin diffuses into the layers of the epidermis and then migrates to the surface of the skin due to the permanent renewal of epidermal cells. It plays a determining role in the color of the skin. Each of us produces melanin but in a different way depending on our origins or even our genes. In all cases, melanin deficiency causes the same pigment disorders and decreases human survivability in extreme hot or cold climes.
Ultraviolet rays have very harmful effects on health. They cause discoloration of the skin, graying and whitening of the hair. UVA rays in particular penetrate very deeply into the skin. At first glance, they accelerate the signs of aging by promoting wrinkles, DNA damage, infertility and age spots. Worse still, they can damage skin cells, thus causing the risk of cancer.
However, the production of protective melanin is seen to degrade over time, due to many factors such as age, pollution, climate extremes, hormones and excessive exposure to the sun.
The lack of melanin causes colossal and quickly visible damage:
On the hair: we observe microscopic cavities or depigmentation of the hair and the hairs which become gray or white. But in addition, they are dull and lackluster. On the skin: you may see spots appear or suffer from vitiligo. In less severe cases, the lack of melanin makes any kind of tanning technique difficult.
The cost of Melanin is around $500 dollars a gram. Melanin is used in various industries and applications. Some of the primary consumers of melanin-related products include the cosmetics, pharmaceutical, computer technology, medical and space research industries. In cosmetics, melanin is often used in skincare products, hair dyes, and tanning lotions to provide pigmentation and sun protection. In the pharmaceutical field, melanin's antioxidant properties make it potentially useful in drug delivery systems and as an ingredient in certain medications.
Furthermore, melanin is of interest in scientific research due to its unique properties. Many scientists for years have been trying to harness its potential for implantable electronics. It has applications in fields such as materials science, bioengineering, and optoelectronics. Researchers and institutions studying melanin and its properties may require melanin samples for their studies, contributing to the demand. The dark Brown or Black melanin pigment, eumelanin, colors hair and eyes, and protects our skin from sun damage. It has also long been known to conduct electricity, but too little for any useful application – until now. In a landmark study published in Frontiers in Chemistry, Italian researchers have subtly modified the structure of eumelanin by heating it in a vacuum.
“The process produced a billion-fold increase in the electrical conductivity of eumelanin,” say study senior authors Dr. Alessandro Pezzella of University of Naples Federico II and Dr. Paolo Tassini of Italian National Agency for New Technologies, Energy and Sustainable Economic Development. “This makes possible the long-anticipated design of melanin-based electronics, which can be used for implanted devices due to the pigment’s biocompatibility.”
It's important to note that the cost of melanin can vary significantly depending on factors such as purity, sourcing, and the specific application it is intended for but this latest discovery could make it double in price in a few years! Some researchers tried to increase the conductivity of eumelanin by combining it with metals, or super-heating it into a graphene-like material – but what they were left with was not truly the biocompatible conducting material promised.
Determined to find the real deal, the Neapolitan group considered the structure of eumelanin.
“All of the chemical and physical analyses of eumelanin paint the same picture – of electron-sharing molecular sheets, stacked messily together. The answer seemed obvious: neaten the stacks and align the sheets, so they can all share electrons – then the electricity will flow.” In essence expose it to heat like sunlight! This finding made many scientists ponder what the effects of global warming will be on black skinned people as we move towards a warmer planet?
This process, called annealing, is used already to increase electrical conductivity and other properties in materials such as metals. For the first time, the researchers put films of synthetic eumelanin through an annealing process under high vacuum to neaten them up – a little like hair straightening, but with only the pigment. “We heated these eumelanin films – no thicker than a bacterium – under vacuum conditions, from 30 min up to 6 hours,” describes Tassini. “We call the resulting material High Vacuum Annealed Eumelanin, HVAE.”
The annealing worked wonders for eumelanin: the films slimmed down by more than half, and picked up quite a tan. “The HVAE films were now dark brown and about as thick as a virus,” Tassini reports. Crucially, the films had not simply been burnt to a crisp. “All our various analyses agree that these changes reflect reorganization of eumelanin molecules from a random orientation to a uniform, electron-sharing stack. The annealing temperatures were too low to break up the eumelanin, and we detected no combustion to elemental carbon.”
A billion-fold increase in conductivity
Having achieved the intended structural changes to eumelanin, the researchers proved their hypothesis in spectacular fashion. “The conductivity of the films increased billion-fold to an unprecedented value of over 300 S/cm, after annealing at 600°C for 2 hours,” Pezzella confirms.
Although well short of most metal conductors – copper has a conductivity of around 6 x 107 S/cm – this finding launches eumelanin well into a useful range for bioelectronics. What’s more, the conductivity of HVAE was tunable according to the annealing conditions.
“The conductivity of the films increased with increasing temperature, from 1000-fold at 200°C. This opens the possibility of tailoring eumelanin for a wide range of applications in organic electronics and bioelectronics. It also strongly supports the conclusion from structural analysis that annealing reorganized the films, rather than burning them.”
There is one potential dampener: immersion of the films in water results in a marked decrease in conductivity.
“This contrasts with untreated eumelanin which, albeit in a much lower range, becomes more conductive with hydration (humidity) because it conducts electricity via ions as well as electrons. Further research is needed to fully understand the ionic vs. electronic contributions in eumelanin conductivity!
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