A net with large holes won't catch small fish. Likewise, the microscopic fibers in the protective mucus coatings of the eyes, lungs, stomach or reproductive system naturally bundle together and allow the tiniest disease-causing bugs, allergens or pollutants to slip by. But Johns Hopkins researchers have discovered a way to chemically shrink the holes in the mucus layer's netting so that it will keep out more of the unwanted particles.
"The mucus layer is an outstanding barrier to most things, but not a perfect one for objects smaller than several hundred nanometers (about 1,000 times smaller than the width a human hair). We still get sick far too often," says Samuel Lai, a chemical and biomolecular researcher in the Whiting School of Engineering and a member of the university's Institute for NanoBioTechnology (INBT).
"The question we asked was, 'Can we shrink the size of the holes in the human mucus barrier to help prevent its penetration by potentially harmful nano-size objects?' " says Justin Hanes, principal investigator of the study and a professor of chemical and biomolecular engineering. Hanes also is director of therapeutics for the INBT.
The team showed that tiny strands in the mucus layer -- the mucin fibers -- naturally tend to bundle and bunch together, creating gaps large enough for pathogens and potentially dangerous pollutants to get in. But by adding a simple detergent to the mix, Lai and his colleagues partially disrupted the bundling of mucin fibers, a procedure that decreased the size of the holes in the mesh. Particles in the range of 200 nanometers in diameter that previously slipped through easily now became trapped in the more finely strung netting.
The findings were reported in the Jan. 28 online edition of the journal PLoS ONE. For this research, the team studied protective coatings taken from the female reproductive tract, conducting high-resolution microscopy experiments with particles as
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| Contact: Mary Spiro mspiro@jhu.edu 410-516-4802 Johns Hopkins University Source:Eurekalert |