The luminal surface of the small intestine is composed of a monolayer of cells overlying a lamina propria comprised of extracellular matrix, ECM, proteins. The ECM provides a porous substrate critical for nutrient exchange and cellular adhesion. The enterocytes within the epithelial monolayer possess proteins such as transporters, carriers, pumps, and channels that participate in the movement of drugs, metabolites, ions and amino acids and whose function can be regulated or altered by the properties of the ECM.
Published in the Journal of Biological Engineering, Ph.D. student Jennifer Speer and her colleagues in the Allbritton Group, characterize expression and function of proteins involved in transport across the human small intestinal epithelium grown on two different culture platforms.
One strategy employs a conventional scaffolding method comprised of a thin ECM film overlaying a porous membrane while the other utilizes a thick ECM hydrogel placed on a porous membrane. The thick hydrogel possesses a gradient of chemical cross-linking along its length to provide a softer substrate than that of the ECM film-coated membrane while maintaining mechanical stability.