(A) Representative images of calcification within GF-BP and ePC-UPy as indicated by radiographic imaging. Red dotted lines define the edge of the material, yellow arrows indicate focal calcification. (B) Mineralization of GF-BP observed histologically by von Kossa (black arrow) and lack of mineralization observed in ePC-UPy, UBM-ECM, and PP at day 21. These comparisons indicate that the susceptibility to calcification often observed for bioprosthetic material, exemplified here for GF-BP, is absent with ePC-UPy, UBM-ECM and PP. (B) von Kossa stain, scale bars 400μm.