Non-physiologic Bioreactor Processing Conditions for Heart Valve Tissue Engineering.

Purpose: Conventional methods of seeding decellularized heart valves for heart valve tissue engineering have led to inconsistent results in interstitial cellular repopulation, particularly of the distal valve leaflet, and notably distinct from documented re-endothelialization. The use of bioreactor conditioning mimicking physiologic parameters has been well explored but cellular infiltration remains challenging. Non-characteristic, non-physiologic conditioning parameters within a bioreactor, such as hypoxia and cyclic chamber pressure, may be used to increase the cellular infiltration leading to increased recellularization.

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

Introduction: 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.

Methods: 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).

Extended bioreactor conditioning of mononuclear cell-seeded heart valve scaffolds.

The tissue-engineered heart valve may be the ideal valve replacement option but still must overcome challenges in leaflet recellularization. This study sought to investigate the potential for leaflet matrix restoration and repopulation following mononuclear cell seeding and extended periods of bioreactor conditioning. Human aortic heart valves were seeded with mononuclear cells and conditioned in a pulsatile bioreactor for 3 days, 3 weeks, or 6 weeks.

Recellularization of decellularized heart valves: Progress toward the tissue-engineered heart valve.

The tissue-engineered heart valve portends a new era in the field of valve replacement. Decellularized heart valves are of great interest as a scaffold for the tissue-engineered heart valve due to their naturally bioactive composition, clinical relevance as a stand-alone implant, and partial recellularization in vivo. However, a significant challenge remains in realizing the tissue-engineered heart valve: assuring consistent recellularization of the entire valve leaflets by phenotypically appropriate cells.

Species-specific effects of aortic valve decellularization.

Unlabelled: Decellularized heart valves have great potential as a stand-alone valve replacement or as a scaffold for tissue engineering heart valves. Before decellularized valves can be widely used clinically, regulatory standards require pre-clinical testing in an animal model, often sheep. Numerous decellularization protocols have been applied to both human and ovine valves; however, the ways in which a specific process may affect valves of these species differently have not been reported.

Pulse Duplicator Hydrodynamic Testing of Bioengineered Biological Heart Valves.

There are many heart valve replacements currently available on the market; however, these devices are not ideal for pediatric patients with congenital heart valve defects. Decellularized valve substitutes offer potential for improved clinical outcomes and require pre-clinical testing guidelines and testing systems suitable for non-crosslinked, biological heart valves. The objective of this study was to assess the hydrodynamic performance of intact, bioengineered pulmonary valves using a custom pulse duplicator capable of testing intact biological valved conduits.