Augmenting Mucus to Keep Out Infection

The beautiful city of San Francisco, where I recently moved to cover materials science for TR, would most certainly benefit from a public-health campaign aimed at preventing its citizens from spitting onto the sidewalks. In this context, mucus is gross. But let’s move past that for a moment, for surely mucus is worthy of our praise. The protective coatings that line tissues including those inside the mouth, lungs, and reproductive tract are part of the body’s first line of defense against infection. Mucus traps viruses, bacteria, and other particles, preventing them from penetrating into the body’s tissues. It’s not foolproof–we still get sick. So researchers at Johns Hopkins University are working on treatments that temporarily improve the mucus barrier’s ability to keep out particles.

Mucus is made up of a mesh of proteins called mucins. The Hopkins team found that mucin strands tend to clump together, creating holes through which pathogens and pollutants can travel. When they used a detergent to disrupt some of this bundling, the researchers decreased the size of the holes so that particles as small as 200 nanometers in diameter were trapped in the mucin mesh. The researchers caution that this hasn’t been tested in people, but they say those who work in places where there are high levels of unhealthy nanoparticles in the air, such as mines, might be protected by inhaling an aerosolized detergent. A similar aerosol might help protect caregivers during an influenza outbreak. Because the mucus is constantly sloughed off and replaced–as when your fellow citizens spit on the sidewalk–the effects of the treatment would last only hours at most.

This research is described in the journal PLoS One.

Watch non-adhesive coated latex beads, each 200 nanometers wide, travel through untreated and treated mucus.

Video courtesy of Public Library of Science One