ORIGINAL ARTICLE Development and Characterization of a Porcine Mitral Valve Scaffold for Tissue Engineering M. Granados 1 & L. Morticelli 1 & S. Andriopoulou 1 & P. Kalozoumis 1 & M. Pflaum 1 & P. Iablonskii 2 & B. Glasmacher 3 & M. Harder 4 & J. Hegermann 5 & C. Wrede 5 & I. Tudorache 2 & S. Cebotari 2 & A. Hilfiker 2,6 & A. Haverich 1,2 & Sotirios Korossis 1,2 Received: 17 November 2016 /Accepted: 10 April 2017 # Springer Science+Business Media New York 2017 Abstract Decellularized scaffolds represent a promising al- ternative for mitral valve (MV) replacement. This work devel- oped and characterized a protocol for the decellularization of whole MVs. Porcine MVs were decellularized with 0.5% (w/ v) SDS and 0.5% (w/v) SD and sterilized with 0.1% (v/v) PAA. Decellularized samples were seeded with human foreskin fi- broblasts and human adipose-derived stem cells to investigate cellular repopulation and infiltration, and with human colony- forming endothelial cells to investigate collagen IV formation. Histology revealed an acellular scaffold with a generally con- served histoarchitecture, but collagen IV loss. Following decellularization, no significant changes were observed in the hydroxyproline content, but there was a significant reduc- tion in the glycosaminoglycan content. SEM/TEM analysis confirmed cellular removal and loss of some extracellular ma- trix components. Collagen and elastin were generally preserved. The endothelial cells produced newly formed col- lagen IVon the non-cytotoxic scaffold. The protocol produced acellular scaffolds with generally preserved histoarchitecture, biochemistry, and biomechanics. Keywords Mitral valve . Heart valve replacement . Decellularization . Biomechanics . Histology . Immunohistochemistry . Biochemistry . α-Gal . Xenoepitope . Collagen IV . Biocompatibility . Tissue engineering . Scaffold . Transmission electron microscopy . Scanning electron microscopy . Cytotoxicity . Scaffold seeding . Humanforeskinfibroblasts . Humanadipose-derived stem cells . Human colony-forming endothelial cells Introduction Heart valve replacement becomes necessary when repair is not possible, or when a previously implanted prosthesis has failed. Current replacement valves include mechanical, bioprosthetic, and cryopreserved homograft valves. Mechanical valves offer excellent long-term durability, but require lifelong anticoagulation therapy. Bioprosthetic valves offer improved hemodynamics, without requiring aggressive anticoagulation. However, they are prone to calcification and structural degra- dation, resulting in limited durability [1]. Currently, cryopre- served pulmonary and aortic valve homografts represent the gold standard in heart valve replacement. However, homo- grafts are associated with limited availability, complex surgi- cal technique, and limited durability [2], the latter of which has been associated to the presence of viable cells that can elicit an immune response [3]. A number of studies have also reported on the clinical use of cryopreserved mitral valve (MV) homografts, with favorable short- and mid-term results, but high long-term failure due to calcification and structural degradation [4–7]. In addition, none of the aforementioned heart valve replacements is able to grow in the pediatric M. Granados and L. Morticelli contributed equally to this work as first authors. Associate Editor Adrian Chester oversaw the review of this article * Sotirios Korossis korossis.sotirios@mh-hannover.de 1 Lower Saxony Centre for Biomedical Engineering, Implant Research and Development, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany 2 Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany 3 Institute for Multiphase Processes, Leibniz University Hannover, Callinstrasse 36, 30167 Hannover, Germany 4 Corlife oHG, Feodor-Lynen-Straße 23, 30625 Hannover, Germany 5 Institute of Functional and Applied Anatomy, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany 6 Leibniz Research Laboratories for Biotechnology and Artificial Organs, Carl-Neuberg-Straße 1, 30625 Hannover, Germany J. of Cardiovasc. Trans. Res. DOI 10.1007/s12265-017-9747-z