New pulsatile bioreactor for in vitro formation of tissue engineered heart valves.

Two potential obstacles to the creation of implantable tissue engineered heart valves are inadequate mechanical properties (ability to withstand hemodynamic stresses) and adverse host-tissue reactions due to the presence of residual nondegraded polymer scaffold. In an attempt to address these problems, we developed an in vitro cell culture system that provides physiological pressure and flow of nutrient medium to the developing valve constructs. It is anticipated that in vitro physical stress will stimulate the tissue engineered heart valve construct to develop adequate strength prior to a possible implantation. Long-term in vitro development will be realized by an isolated and thereby contamination-resistant system. Longer in vitro development will potentially enable more complete biodegradation of the polymeric scaffold during in vitro cultivation. This new dynamic bioreactor allows for adjustable pulsatile flow and varying levels of pressure. The system is compact and easily fits into a standard cell incubator, representing a highly isolated dynamic cell culture setting with maximum sterility, optimal gas supply and stable temperature conditions especially suited for long-term experiments.