Clearing Things Up: A Vertical Mucus Clearance Assay to Investigate Rheological and Biochemical Parameters Governing Mucociliary Clearance.
Public Deposited- Last Modified
- March 22, 2019
- Creator
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Carpenter, Jerome
- Affiliation: College of Arts and Sciences, Department of Applied Physical Sciences
- Abstract
- Mucociliary clearance (MCC) plays an essential role to protect the airways from pathogens and pollutants. Impaired MCC leads to a host of diseases and initiates a cascade of chronic infection, inflammation, and reduced lung function. Understanding the mechanisms of clearance is a critical step in preventing and ultimately treating disease. The fundamental mechanisms guiding clearance are still poorly understood. Existing models have focused on fluid rheology, but haven't reached a consensus on which parameters govern the system. In this work I build an in vitro model capable of evaluating rheological and biochemical parameters and their effect on clearance. My model integrates the air-liquid interface (ALI) bronchial epithelial cell culture model with microfluidics to create a mucus clearance assay (MCA). Growing well-ciliated cells inside of a fluidics channel allows me to use external flow to investigate cilia-ASL interactions. I use external flow to build and validate a model of cilia hydrodynamics. Then I demonstrate external flow can be used as a force probe to investigate adhesion on the epithelial surface. Next I integrate the MCA with a tilting microscope to explore the effects of gravity on mucociliary clearance. Gravity has been largely ignored in mucus clearance experiments despite vertical transport in vivo and therapies exploiting gravitational drainage. I observe fluids transporting horizontally, but failing to transport when the cilia driven flow is opposed by gravity. This establishes gravitational effects as a necessary requirement for evaluating the parameters that govern MCC. Next I tested a 4.5% 1MDa PEG solution that matched the apparent viscosity of mucus and observed that unlike mucus, the PEG solution didn't transport vertically. This experiment demonstrates that viscosity alone is not a predictor of vertical transport. Finally I suggest that the inability to transport vertically is a result of the system dehydrating and posit that mucus' ability to transport vertically is the result of biochemical adhesion with the cilia.
- Date of publication
- May 2013
- DOI
- Resource type
- Rights statement
- In Copyright
- Advisor
- Superfine, Richard
- Degree
- Doctor of Philosophy
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 2013
- Language
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