acellularisation and consecutive in vitro autogeneic re-seeding of valved venous conduits can lead to immunologically acceptable, patent, and competent implants in sheep.

Treatment with SD and DNase enables complete decellularisation of human valve containing veins whereas 3D matrix components such as collagen and elastin remain preserved. The lumen of the scaffold including the valves can be successfully re-seeded with a human EC monolayer in a 3D bioreactor. There is substantial evidence that hABS and not FCS is essential for the completion of cell-matrix contacts in human veins.

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Objective Degradation mechanisms of cardiovascular bioprostheses may play an important role in bioartificial implants. The fate of acellular implanted and cellular cardiovascular scaffolds was examined in an in vivo model. Methods Decellularized or native ovine carotid artery (CA, n=42) and aorta (AO, n=42) were implanted subcutaneously into rats for 2, 4 and 8 weeks. Immunohistochemical methods were used to monitor repopulation. Desmin-vimentin, CD31-, CD4- and CD18-antibodies for myocytes, endothelium, and inflammatory cell-infiltration, respectively. Calcification was detected by von-Kossa staining. Cell density was quantified by DNA-isolation. Results Acellular AO and CA matrices showed progressive calcification. Cellular AO and CA matrices trigger a strong inflammatory reaction which subsides after two weeks. CA scaffolds are revascularized progressively, whereas AO biocomposites degenerate. Calcification is less pronounced in cellular AO scaffolds and lacking in CA. Conclusions Acellular bioartificial implants demonstrate degradation mechanisms similar to currently applied cardiovascular bioprostheses. Cellularized viable implants are promising clinical alternatives.

Acellularised porcine matrix scaffolds can be used for cardiovascular tissue engineering of autologous grafts without risk of PERV transmission.