Tuberculosis is a contagious, potentially lethal disease that is said to have infected one-third of the world’s population in its latent form. Sometime during your life, you’ve probably received a Mantoux test for TB (aka “the bubble test”) in which a sample of purified TB protein derivative is injected just beneath the skin. The Mantoux test, however, is tricky to administer as the injection must be made at a precise angle and depth in the arm, and there are a number of factors that can easily cause false negative or false positive results.
Researchers at the University of Washington have developed a patch made up of tiny microneedles coated with purified TB protein derivative which could make TB testing much more painless for both patients and clinicians. As the microneedles measure just 750 micrometers long, they’re too short to reach nerves in the skin that register pain, so applying the patch feels like putting on a band-aid. Moreover, because the delivery of the TB protein using the patch depends on the length of the microneedle rather than the angle, the patch test will be far easier for clinicians to administer than a Mantoux test and will ensure that the TB derivative is being properly injected.
Environmentalists will be pleased too; another benefit of the microneedle patch is that it is biodegradable. The microneedles are made of chitin, a naturally-occurring, tough material found in the exoskeletons of insects and crustaceans.
Journal abstract from Advanced Healthcare Materials: Chitin Microneedles for an Easy-to-Use Tuberculosis Skin Test
Article from UW: Microneedle patch could replace standard tuberculosis skin test…
