(P 331) Re-Endothelialization of Decellularized Pulmonary Valve Scaffold Under Simulated Physiological Dynamic Conditions In-Vitro

• Published in: Tissue engineering. Part A 2008-05, Vol.14 (5), p.903-903
• Main Authors: Lichtenberg, A, Tudorache, I, Cebotari, S, Suprunov, M, Akhyari, P, Tudorache, G, Haverich, A, Hilfiker, A
• Format: Article
• Language: English
• ISSN: 1937-3341; 1937-335X

Objective: Optimization of techniques for serial production of viable biological heart valves is of central interest in bio-engineering. The aim of study was to generate decellularized heart valves with preserved ultra-structure and to repopulate those with endothelial cells (EC) under simulated physiological conditions. Methods: Ovine pulmonary valve conduits (n = 16) were decellularized in detergents (Sodium-deoxycholate/SDS) followed by 8 wash cycles in PBS (12 h each). Viability of EC cultures exposed to washing solution served to prove efficiency of washing. Luminal surfaces of decellularized grafts (n = 11) were seeded with ovine jugular vein EC (1.2x 10 super(7) cells) in special bioreactors. After rolling culture for 48h, pulsatile circulation was started with a flow of 0.1 L/min (system mean pressure: 25 plus or minus 4 mmHg). The flow rate was gradually increased with 0.3 L/day to a final rate of 2.0 L/ min (cycle rate: 60 beats/min), while pH, pO sub(2), pCO sub(2), lactate and glucose in the medium were maintained at constant physiological levels. Results: Resulting scaffolds were cell-free with preserved architectonic of extracellular matrix. Biomechanical tests demonstrated comparable properties to native tissue (n = 5). Histological examination, after 7d of dynamic cultivation, revealed a cells monolayer covering the inner valve surface. Metabolic assays demonstrated high activity of these cells, which express im-munohistochemically vWF/eNOS, indicating an endothelial origin. Electron microscopy revealed their, typical endothelial, cobble-stone arrangement. Conclusion: Complete and flow-resistant re-endothelialization of detergent decellularized matrix can be achieved in a pulsatile bioreactor system under conditions simulating physiological environment. Permanent monitoring of biotechnological processes and continuous adjustment to physiological parameters is essential for cardiac valve engineering.