27 April 2006 From New Scientist Print Edition. said:
Tattoos made of 'disappearing' ink!
IF YOU are planning to express your undying love for someone with a tattoo, you might want to wait a little while before going under the needle. New inks that are safer to use, and far easier to remove should you have a change of heart, are set to be launched next year.
The US Food and Drug Administration has no standards for the safety of dyes used in body art. Carbon black, metal salts and other compounds more commonly used in printing or car paint are among those used. Heavy metals and other toxic chemicals in these pigments can seep into the lymph system, says Martin Schmieg, president of the company Freedom-2 in Philadelphia, which is planning to introduce a range of dyes that have already been approved by the FDA for use in cosmetics, food, drugs and medical devices.
Such dyes have not been used in tattoos before as they are readily absorbed by the body. To get round this problem, Rox Anderson at the Massachusetts General Hospital in Boston has developed a way to encapsulate the dyes in protective polymer beads just 1 to 3 micrometres in diameter. This is small enough to allow them to be injected into the skin and absorbed by skin cells to form a tattoo.
The pigment can be removed with a single laser treatment. This splits the beads open, dumping the dye into cells where it is absorbed. The tattoo then quickly fades away, in stark contrast to standard tattoo pigments. Applying a series of up to 10 laser treatments can usually bleach them, but only half of tattoos can be completely removed.
