Non-Invasive analysis of synthetic and decellularized scaffolds for heart valve tissue engineering

Aims: Micro computerized tomography (µ-CT) is a non-destructive, high-resolution, three dimensional analysis of objects. The aim of this study was to evaluate the feasibility of using µ-CT scanner as a non-invasive evaluation method for tissue engineering applications. Material and methods: Polyurethane aortic valve scaffolds were produced at the ITV-Denkendorf by the spraying technique. Cryopreserved/thawed homografts and biological valves were decellularized by using a detergent mixture (0.5% sodium deoxycholate and 0.5% sodium dodecyl sulfate). Human vascular fibroblasts (FBs) and endothelial cells (ECs) were isolated from saphenous vein segments and expanded in culture. Scaffolds of all groups were primarily seeded with human FBs followed by a colonization with ECs. Scaffolds were scanned before, after decellularization and after cell colonization with a µ-CT scanner. Colonization efficiency was additionally controlled by scanning electron microscopy (SEM) and immunohistochemical staining (IHC). Results: SEM results showed a confluent cell layer on all scaffold materials. IHC staining with CD31 (EC-Antibody) and TE-7 (FB-Antibody) revealed a positive reaction of both cell layers after a rest period of 7 days. Micro-CT Data allowed a quantitative visualization of the decellularization and seeding steps. Conclusion: Micro-CT offers a non-invasive effective method for the visualization and analysis of tissue engineering processes.