Microneedle patch tests for malaria without needing to draw blood
Malaria is responsible for hundreds of thousands of deaths each year, with testing for the disease involving blood sampling and then trained medical professionals to reach a result. Engineers at Rice University have designed a new bandage-like microneedle device that could greatly improve access to this type of diagnostic, with the ability to detect key markers of the disease without drawing any blood at all.
Much like other microneedle patches that could slowly drip feed cancer drugs into melanomas, deliver vaccines in the form of silver-loaded nanoparticles or offer month-long contraception, the device developed at Rice University is designed to be entirely pain-free.
The patch uses a set of 16 tiny needles to gently pierce the skin, but not in a way that causes discomfort. This is because the needles measure just 375 microns wide, and subtly draw in dermal interstitial fluid, which surrounds all the cells in our skin and can contain certain biomarkers that can reveal the presence of a disease.
"Xue (postdoctoral researcher Xue Jiang) and I have applied the patch to our skin, and it doesn’t feel painful at all compared to a finger prick or a blood draw," says Rice University mechanical engineer Peter Lillehoj. "It’s less painful than getting a splinter. I would say it feels like putting tape on your skin and then peeling it off."
Along with the array of microneedles, the patch features a test strip for analyzing the fluid, which contains antibodies that react in the presence of certain biomarkers – in this case those indicating malaria. The device is able to carry out this process and deliver a result in 20 minutes via red lines on the strip’s exposed surface, indicating a positive or negative result.
These patches are estimated to cost around US$1 apiece if produced in bulk, and can simply be peeled off and thrown away once the job is done. This makes them a promising solution for malaria testing in developing regions, where health care and trained professional may not be as widely available. The team also says the device could be tailored to search for biomarkers of other diseases, including potentially COVID-19.
The research was published in the journal Microsystems and Nanoengineering.
Source: Rice University