Researchers have developed a micro-needle system capable of monitoring medication drugs in the body, which could one day replace costly, invasive blood withdrawals and improve patient comfort.
Created at the University of British Columbia in Canada and the Paul Scherrer Institut (PSI) in Switzerland, the new system consists of a small, thin patch that is pressed against a patient's arm during medical treatment and measures drugs in their bloodstream painlessly without drawing any blood. The tiny needle-like projection, less than half a millimeter long, resembles a hollow cone and does not pierce the skin like a standard hypodermic needle.
"Many groups are researching micro-needle technology for painless vaccines and drug delivery," said the researchers involved in the new system, "however, using them to painlessly monitor drugs is a newer idea."
Micro-needles are designed to puncture the outer layer of skin, which acts as a protective shield, but not the next layers of epidermis and the dermis, which house nerves, blood vessels and active immune cells.
The new micro-needle system can use the fluid found just below the outer layer of skin, instead of blood, to monitor levels of drugs in the bloodstream. The micro-needle collects just a tiny bit of this fluid, less than a millionth of a milliliter, and a reaction occurs on the inside of the micro-needle that researchers can detect using an optical sensor. This technique allows researchers to quickly and easily determine the concentration of drugs in the blood.