Endothelialization of heart valve matrix using a computer-assisted pulsatile bioreactor

Area of Science:

• Biomaterials Science
• Cardiovascular Engineering
• Tissue Engineering

Background:

• Bioprosthetic heart valves are prone to calcification and tissue deterioration, leading to thromboembolism.
• Endothelialization of valve surfaces is a strategy to minimize thrombosis.
• Optimal conditions for endothelialization of decellularized heart valves require investigation.

Purpose of the Study:

• To define optimal flow parameters for endothelialization of decellularized heart valves using endothelial progenitor cell (EPC)-derived endothelial cells (ECs).
• To assess the thrombogenic characteristics of endothelialized heart valve surfaces using a bioreactor.

Main Methods:

• Decellularized porcine valve scaffolds were seeded with EPC-derived ECs.
• A computer-controlled bioreactor system was used to determine optimal flow rates.
• Successful endothelialization was achieved by preconditioning cell-seeded valves with stepwise increases in volume flow rate up to 2 L/min for 7 days.

Main Results:

• EC-seeded decellularized valve scaffolds demonstrated improved anti-thrombotic properties.
• Unseeded scaffolds showed an escalation of the coagulation process.
• Bioreactor preconditioning facilitated uniform endothelialization of valve scaffolds.

Conclusions:

• Bioreactor-mediated preconditioning is essential for uniform endothelialization of EC-seeded valve scaffolds.
• This approach may significantly reduce thrombotic activity after in vivo implantation of bioprosthetic heart valves.
• Optimized endothelialization enhances the safety and efficacy of bioprosthetic heart valves.