Figure 15.

Leaflets of two different electrospun heart valves made of the biodegradable supra-molecular polymer bisurea-modified poly-carbonate (PC-BU) after 24 weeks of trans-catheter pulmonary valve replacement in the sheep. The leaflet cellularity generally decreased with distance to the leaflet base with minimal tissue deposition observed toward the free edges. Leaflet remodeling depended on stent integration in the surrounding tissue with transmural population of the leaflet base with polymer absorption and ECM deposition in the well-integrated valve (A) and poor cell population, surface overgrowth of tissue and a lack of collagen deposition in valve (B), which was in line with its poor stent integration and migration over time indicating the dependence of the cell population of the leaflet scaffold on transmural ingrowth. From (158) with permission.