A Pulsatile Bioreactor for Conditioning of Tissue-Engineered Cardiovascular Constructs under Endoscopic Visualization

Heart valve disease (HVD) is a globally increasing problem and
accounts for thousands of deaths yearly. Currently end-stage HVD
can only be treated by total valve replacement, however with major
drawbacks. To overcome the limitations of conventional substitutes,
a new clinical approach based on cell colonization of artificially
manufactured heart valves has been developed. Even though this
attempt seems promising, a confluent and stable cell layer has not
yet been achieved due to the high stresses present in this area of
the human heart. This study describes a bioreactor with a new
approach to cell conditioning of tissue engineered heart valves.
The bioreactor provides a low pulsatile flow that grants the
correct opening and closing of the valve without high shear
stresses. The flow rate can be regulated allowing a steady and
sensitive conditioning process. Furthermore, the correct
functioning of the valve can be monitored by endoscope surveillance
in real-time. The tubeless and modular design allows an accurate,
simple and faultless assembly of the reactor in a laminar flow
chamber. It can be concluded that the bioreactor provides a strong
tool for dynamic pre-conditioning and monitoring of colonized heart
valve prostheses physiologically exposed to shear stress.