Microneedle technology has been around for years, and we've seen vaccines and medication administered via the technique, which uses tiny needles to break only the upper layer of the patient's skin. Now, the pain-free tech is being used for something a little different, with researchers creating a device capable of monitoring patient drug levels – something that usually requires the drawing of blood.
The development of the new system was a joint effort between the University of British Columbia (UBC) and the Paul Scherrer Institute (PSI) in Switzerland. It consists of a small patch that's pressed against the skin of the patient, with a needle-like point, less than half a milimeter in length, which pierces only the top layer of skin, leaving the epidermis and dermis intact.
Rather than draw comparatively large volumes of blood from patients, the microneedle system instead focuses on the fluid found just beneath the outer layer of skin, known as interstitial fluid.
A tiny reservoir in the needle collects a sample, less than a million of a millilitre in volume, at which point any drug molecules present bind to the interior surface of the microneedle. Micro-optical fibers are present in the tiny sensor, detecting color changes – caused by the drug binding – in a clear fluid that's then passed through the device. That data is used to describe the concentration of a given drug in the fluid.
The version of the device created by the researchers is designed to monitor levels of the antibiotic vancomycin. It's usually administered via an intravenous line, and is used to treat serious infections. In order to makes sure that the antibiotic isn't causing dangerous toxic side effects, doctors currently have to draw blood from patients three or more times a day.
So far, the researchers have successfully tested the system in the lab, and are currently working towards clinical trials, which are expected to take place within the next two years. Should the system prove effective in human testing, it could provide a far less intrusive means of keeping a close eye on patient health during treatment.
The research is published online in the journal Scientific Reports.