Comparison of Candidate Cell Populations for the Recellularization of Decellularized Heart Valves

Heart valve tissue engineering may provide improved treatment for valvular heart disease, yet development of a tissue engineered heart valve (TEHV) has been limited by incomplete recellularization of the valve leaflets. In this study, we compare the leaflet recellularization potential of candidate cell populations.

Four cell populations were tested: bone marrow mononuclear cells (MNC), 5 million bone marrow mesenchymal stem cells (MSC), 10 million bone marrow mesenchymal stem cells (MSC2), and 5 million valve interstitial cells (VIC). Candidate cell populations were seeded onto decellularized heart valves and underwent similar conditioning in a low-flow bioreactor for 2 weeks.

MSC2 valves demonstrated the best recellularization of the interstitial leaflet tissue as well as an appropriate cell phenotype, mechanical properties, and biochemical composition. MSC valves exhibited similar leaflet repopulation, yet had decreased mechanical and biochemical properties. MNC seeding resulted in minimal recellularization of the leaflet, though an additional time point group found cells present after 3 days, which seemed to disappear at 2 weeks. VIC seeding resulted in cell clumping on the leaflet surface and poor recellularization.

The results of this study suggest mesenchymal stem cells are a preferred cell population for TEHV recellularization. Additionally, MSCs demonstrate the ability for repopulation of the distal valve leaflet, which will lead to more complete recellularization of future TEHVs.