title: Characterization of particle translocation through mucin hydrogels.
abstract: Biological functional entities surround themselves with selective barriers that control the passage of certain classes of macromolecules while rejecting others. A prominent example of such a selective permeability barrier is given by mucus. Mucus is a biopolymer-based hydrogel that lines all wet epithelial surfaces of the human body. It regulates the uptake of nutrients from our gastrointestinal system, adjusts itself with the menstrual cycle to control the passage of sperm, and shields the underlying cells from pathogens such as bacteria and viruses. In the case of drug delivery, the mucus barrier needs to be overcome for successful medical treatment. Despite its importance for both physiology and medical applications, the underlying principles which regulate the permeability of mucus remain enigmatic. Here, we analyze the mobility of microscopic particles in reconstituted mucin hydrogels. We show that electrostatic interactions between diffusing particles and mucin polymers regulate the permeability properties of reconstituted mucin hydrogels. As a consequence, various parameters such as particle surface charge and mucin density, and buffer conditions such as pH and ionic strength, can modulate the microscopic barrier function of the mucin hydrogel. Our findings suggest that the permeability of a biopolymer-based hydrogel such as native mucus can be tuned to a wide range of settings in different compartments of our bodies.
authors.affiliation: Faculty of Arts and Sciences, Center for Systems Biology, Harvard University, Cambridge, Massachusetts, USA. olieleg@MIT.edu
authors.forename: Oliver
authors.initials: O
authors.lastname: Lieleg
authors.forename: Ioana
authors.initials: I
authors.lastname: Vladescu
authors.forename: Katharina
authors.initials: K
authors.lastname: Ribbeck
mesh_terms: D000818:Animals; D001692:Biological Transport; D002021:Buffers; D004058:Diffusion; D006801:Humans; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D008968:Molecular Conformation; D009038:Motion; D009077:Mucins / Q000737:chemistry* / Q000378:metabolism*; D009994:Osmolar Concentration; D010316:Particle Size; D010539:Permeability; D011137:Polystyrenes / Q000737:chemistry / Q000378:metabolism; D012492:Salts / Q000737:chemistry; D013499:Surface Properties
chemical_list: D002021:Buffers; D020100:Hydrogels; D009077:Mucins; D011137:Polystyrenes; D012492:Salts