title: Diffusion through Pig Gastric Mucin: Effect of Relative Humidity.
abstract: Mucus covers the epithelium found in all intestinal tracts, where it serves as an important protecting barrier, and pharmaceutical drugs administrated by the oral, rectal, vaginal, ocular, or nasal route need to penetrate the mucus in order to reach their targets. Furthermore, the diffusion in mucus as well as the viscosity of mucus in the eyes, nose and throat can change depending on the relative humidity of the surrounding air. In this study we have investigated how diffusion through gels of mucin, the main protein in mucus, is affected by changes in ambient relative humidity (i.e. water activity). Already a small decrease in water activity was found to give rise to a significant decrease in penetration rate through the mucin gel of the antibacterial drug metronidazole. We also show that a decrease in water activity leads to decreased diffusion rate in the mucin gel for the fluorophore fluorescein. This study shows that it is possible to alter transport rates of molecules through mucus by changing the water activity in the gel. It furthermore illustrates the importance of considering effects of the water activity in the mucosa during development of potential pharmaceuticals.
authors.affiliation: Biomedical Science, Faculty of Health and Society, Malmö University, Malmö, Sweden.|Biofilms-Research Center for Biointerfaces, Malmö University, Malmö, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Runnsjö
authors.affiliation: Division of Physical Chemistry, Lund University, Lund, Sweden.
authors.forename: Aleksandra P
authors.initials: AP
authors.lastname: Dabkowska
authors.affiliation: Division of Physical Chemistry, Lund University, Lund, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Sparr
authors.affiliation: Biomedical Science, Faculty of Health and Society, Malmö University, Malmö, Sweden.|Biofilms-Research Center for Biointerfaces, Malmö University, Malmö, Sweden.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Kocherbitov
authors.affiliation: Biomedical Science, Faculty of Health and Society, Malmö University, Malmö, Sweden.|Biofilms-Research Center for Biointerfaces, Malmö University, Malmö, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Arnebrant
authors.affiliation: Biomedical Science, Faculty of Health and Society, Malmö University, Malmö, Sweden.|Biofilms-Research Center for Biointerfaces, Malmö University, Malmö, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Engblom
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism; D004058:Diffusion; D019793:Fluorescein / Q000378:metabolism; D005752:Gastric Mucins / Q000378:metabolism*; D005782:Gels / Q000378:metabolism; D006813:Humidity; D008795:Metronidazole / Q000378:metabolism; D011092:Polyethylene Glycols; D013552:Swine; D014867:Water / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D005752:Gastric Mucins; D005782:Gels; D014867:Water; D008795:Metronidazole; D011092:Polyethylene Glycols; D019793:Fluorescein