Scientists Finally Know Why Tattoo Ink Lasts

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Scientists Finally Know Why Tattoo Ink Lasts Even Though Skin Regenerates
No wonder they're so hard to get rid of.

By Peter Hess on March 6, 2018

 

If the skin regenerates itself every couple of weeks, then why do tattoos last for years? Sure, we know that tattoo ink is inserted into the layer right beneath the outermost layer of skin, but even the cells there must regenerate eventually. The seeming paradox of tattoo permanence has hurt the brains of even the most science-savvy ink enthusiasts. Fortunately, on Tuesday, a team of researchers report they’ve found a solution.

 

In a paper published in the Journal of Experimental Medicine, French scientists showed that tattoos stay in the skin because cells in the skin actively ensure the ink pigments stay in one place. The particles of ink pigment, they write, are repeatedly passed on from old cells to the new ones that are coming to replace them, sort of like an immune system relay race baton. The key finding is the identity of those cells: the macrophages, immune system cells that encapsulate foreign bodies like bacteria or tattoo pigments.

 

“A lack of consensus regarding how to identify the immune cell types present in the skin has hampered the precise identification of the cells that capture the ink particles found in tattoo paste and retain them in situ for an extended period,” Sandrine Henri, Ph.D., and Bernard Malissen, Ph.D., both at the Immunology Centre of Marseille-Luminy in France, tell Inverse in a joint email. Henri and Malissen co-authored the paper along with 12 other researchers.

 

Macrophages are super tenacious in their efforts to hold onto ink pigments, which explains why even after laser tattoo removal surgery, traces of the ink still remain. New macrophages gobble up the scattered fragments of ink and hold them in place within the skin.

 

Macrophages encapsulate green tattoo ink pigment (left) and release it when the cells are killed (center). But 90 days later, new macrophages develop and swallow up the pigment again (right).

 

This research fills in a significant gap in scientific understanding about why tattoos remain in the skin for so long. Even though we have tattooed each other for thousands of years, we’re only now beginning to understand exactly how tattoos behave inside our bodies. Now that science is showing exactly how this process occurs beneath the surface of the skin, the study’s authors hope to improve tattoo removal techniques.

 

More at Source

 

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Another interesting article: "Tattoos Last Forever Because Your Immune Cells Are Hungry for Dead Skin"

 

You can thank your immune system for many things — such as preventing your body from turning into an alien fungus or permitting you to live outside of a plastic bubble. You can also thank your immune system for keeping your dope new shoulder tattoo from flaking off with the dead skin cells you lose every day, according to a team of French immunologists who tattooed the tails of mice.

 

In a new paper, published today (March 6) in the Journal of Experimental Medicine, researchers determined that tattoo pigment is held in the dermis (the middle of your three layers of skin) by a single type of white blood cell known as a macrophage.

 

These immune-response cells swarm to the site of a new tattoo when the needle punctures your skin, gobbling up ink pigments that they deem to be foreign invaders before settling into the dermis until they die. According to the new paper, that's when an effective, extracellular recycling program kicks into gear — and keeps your tattoo a permanent part of your cellular network. [5 Weird Ways Tattoos Affect Your Health]

 

"Macrophages, including those that that are laden with tattoo pigments, do not live as long as a human being," study co-author Sandrine Henri, aresearcher at the Centre d'Immunologie de Marseille-Luminy in France, told Live Science in an email. "When they die [within a few years], they release into the dermis the pigments they contain. These free pigments are then taken up by the neighboring macrophages, which seem to be the only skin cells capable to handle them."

 

In the new study, researchers tattooed a green, striped pattern onto the tails of several genetically engineered mice whose dermal macrophages could be easily targeted for destruction (without posing a lethal risk to the mouse). After a few weeks, the tattooed mice received an injection to specifically kill off macrophages carrying green pigment. Within two days, all of the pigment-carrying macrophages had died off — but the tattoos did not fade.

 

Taking a closer look, the researchers saw that new macrophages began replacing the dead ones almost instantly, slurping up pigment upon arriving. Within 90 days, the pool of cells had replenished completely and gobbled up most of the loose tattoo pigments again.

 

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International tattoo festival leaves its mark on Venezuela

The vids linked in the article are stunning.........

 

https://www.telegraph.co.uk/news/worldnews/southamerica/venezuela/11381515/International-tattoo-festival-leaves-its-mark-on-Venezuela.html

 

 

 

More than 400 tattoo artists from around the world are participating in the event, which started on Thursday and will run until Sunday.