Interstitial heart valve cells are responsible for maintaining the structural integrity of heart valve leaflets. Abrupt changes in mechanical environment, e.g. valve injury or hypertension, differentiate these cells into a very contractile and synthetic phenotype, which results in shrinkage and stiffening of the heart valve tissue. Excessively stiffened and thickened heart valve leaflets lose their capability of opening and closing appropriately, leading to thousands of heart valve replacement surgeries annually.
In the present study, we aimed to quantify the effects of tissue boundary on heart valve cell phenotype. To this end, we used silicon cantilevers for measuring contractility of pig heart valve cells cultured in fibrin gel micro-tissues. We detected significant increase in heart valve cell contractility with increasing levels of boundary stiffness. Our results suggest that stiff areas of the heart valve may potentiate contraction based pathology in adjacent healthy tissues. Next generation surgical modalities may make use of our findings to prevent or treat heart valve pathologies.
Mehmet Hamdi Kural, PhD candidate
Biomedical Engineering Department
Worcester Polytechnic Institute, Worcester, MA USA