Affiliations: Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
Note: [] Address for correspondence: Dr. Mark Johnson, TECH Room E378, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA. Fax: +1 847 491 4928; E-mail: m-johnson2@northwestern.edu.
Abstract: In this study, we measured the specific hydraulic conductivity (K) of Matrigel™ at 1% and 2% concentrations as a function of perfusion pressure (0 to 100 mmHg) and compared the results to predictions from two models: a fiber matrix model that predicted K of the gel based upon its composition, and a biphasic model that predicted changes in K caused by pressure induced compaction of the gels. The extent of gel compaction as a function of perfusion pressure was also assessed, allowing us to estimate the stiffness of the gels. As expected, 2% Matrigel™ had a lower K and a higher stiffness than did 1% Matrigel™. Measured values of K of both 1% and 2% Matrigel™ samples showed good agreement with the predictions of the fiber matrix model. Pressure-induced changes in K were better described by the biphasic model than a model in which uniform compression of the gel was assumed. We conclude that K of multi-component gels, such as Matrigel™can be well characterized by fiber matrix models, and that pressure-induced changes in K of such gels can be well characterized by biphasic models.
