Abstract
A novel microneedle patch, developed by a team of engineers at Washington University, St. Louis, can both capture biomarkers and allow clinicians to detect the presence of low levels of bio-markers when applied to the skin. The low-cost technology has the potential to eliminate the need for patients to travel to the hospital or lab for a blood draw and provide an easy method for at-home testing.
“We used plasmonic-fluor—an ultrabright fluorescent label—to improve the limit of detection of various interstitial fluid protein biomarkers by nearly 800-fold compared with conventional fluorophores, and a magnetic backing layer to … improve measurement consistency,” the investigators wrote in the journal Nature Biomedical Engineering.
In addition to the low cost and ease of use, these microneedle patches have another advantage over blood draws, perhaps the most important feature for some: “They are entirely pain-free,” said Srikanth Singamaneni, Ph.D., a professor at Washington University who led the research. They “go about 400 microns deep into the dermal tissue. They don't even touch sensory nerves.”
Finding a biomarker using these microneedle patches is similar to blood testing. But instead tests the dermal interstitial fluid. Using plasmonic-fluor, the research team was able to detect bio-markers on the order of picograms per milliliter, orders of magnitude more sensitive than other methods.
The team now needs to determine clinical cutoffs for the device, i.e., the range of biomarker in interstitial fluid that corresponds to a normal versus an abnormal level. They are also working on delivery methods for long distances and harsh conditions, providing options for improving rural healthcare.