title: Readily available porcine aortic valve matrices for use in tissue valve engineering. Is cryopreservation an option?
abstract: The clinical use of acellular biological valves as scaffolds in tissue valve engineering would require them to be readily available. This study examines the feasibility of cryopreserving porcine aortic valve matrices for use in tissue valve engineering. Matrices prepared using an enzymatic-detergent decellularization protocol were examined before and after cryopreservation. The biochemical status of tissues were evaluated by collagen and uronic acid (proteoglycan) determination and their mechanical properties were determined using a burst test. The histological and ultrastructural properties were evaluated by light and electron microscopy. Cryopreservation did not significantly affect the collagen and uronic acid content of aortic leaflet matrices. Histological and ultrastructural sections, however, confirmed extensive disruption of the extracellular collagen matrix and inter-fibrillar proteoglycan associations following cryopreservation. Although neither the breakage force nor the maximum force at failure was significantly different in matrices before and after cryopreservation, the strain observed in matrices was significantly higher after cryopreservation. To our knowledge this is the first study to investigate the effects of cryopreservation on aortic valve matrices. Cryopreservation did not significantly alter the biochemical properties of porcine aortic valve matrices. Nevertheless, cryopreservation had significant adverse effects on the structural and mechanical properties of matrices. Cryopreserved matrices showed significantly higher strain when stressed compared to non cryopreserved matrices. While, theoretically matrices are only expected to be functional for a limited time until regenerated in vivo, further mechanical testing is necessary to evaluate the effects of these changes on the durability of porcine aortic valve matrices for use in tissue valve engineering.
authors.affiliation: Department of Cardiac Surgery K12 5Ve, The University Hospital Ghent, De Pintelaan 185, 9000 Ghent, Belgium. kishan.narine@UGent.be
authors.forename: Kishan
authors.initials: K
authors.lastname: Narine
authors.forename: Erik Claeys
authors.initials: EC
authors.lastname: Ing
authors.forename: Maria
authors.initials: M
authors.lastname: Cornelissen
authors.forename: Filip
authors.initials: F
authors.lastname: Desomer
authors.forename: Hilde
authors.initials: H
authors.lastname: Beele
authors.forename: Lieva
authors.initials: L
authors.lastname: Vanlangenhove
authors.forename: Stefaan De
authors.initials: SD
authors.lastname: Smet
authors.forename: Guido Van
authors.initials: GV
authors.lastname: Nooten
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism*; D001021:Aortic Valve / Q000378:metabolism* / Q000473:pathology*; D003094:Collagen / Q000737:chemistry; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D003902:Detergents / Q000494:pharmacology; D004798:Enzymes / Q000737:chemistry; D005109:Extracellular Matrix / Q000378:metabolism; D006350:Heart Valve Prosthesis; D011509:Proteoglycans / Q000737:chemistry; D013314:Stress, Mechanical; D013552:Swine; D023822:Tissue Engineering / Q000379:methods*; D014574:Uronic Acids / Q000737:chemistry
chemical_list: D003451:Cryoprotective Agents; D003902:Detergents; D004798:Enzymes; D011509:Proteoglycans; D014574:Uronic Acids; D003094:Collagen