Microneedle can monitor drugs in bloodstream without pain or blood draws

University of British Columbia's microneedle.

Researchers at the University of British Columbia and Switzerland’s Paul Scherrer Institut have come up with a microneedle that can painlessly measure drugs in a patient’s bloodstream without requiring expensive and invasive blood draws.

The device is a small, thin patch that is pressed against a patient’s arm during medical treatment. Its minute, needle-like projection measures less than half a millimeter long and doesn’t penetrate the skin like a standard hypodermic needle.

The microneedle is designed to puncture the outer layer of skin, but not the next layers of epidermis and the dermis, which house nerves, blood vessels and active immune cells.

“Many groups are researching microneedle technology for painless vaccines and drug delivery,”  Sahan Ranamukhaarachchi, a PhD student who developed the technology, told a UBC publication. “Using them to painlessly monitor drugs is a newer idea.”

Originally designed to monitor the antibiotic vancomycin, which requires as many as four blood draws daily, the researchers found they could use the fluid just below the outer layer of skin, instead of blood, to monitor levels of the antibiotic in the bloodstream.

The microneedle captures less than a millionth of a milliliter of the fluid, causing a reaction inside the microneedle that researchers can monitor using an optical sensor. The technique allows them to quickly and easily determine the concentration of vancomycin.

“This is probably one of the smallest probe volumes ever recorded for a medically relevant analysis,” said Urs Hafeli, an associate professor of pharmaceutical sciences at UBC.

The microneedle monitoring system was outlined in a paper published earlier this month in Scientific Reports.

- check out the UBC story

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