title: Age dependent differences in collagen alignment of glutaraldehyde fixed bovine pericardium.
abstract: Bovine pericardium is used for heart valve leaflet replacement where the strength and thinness are critical properties. Pericardium from neonatal animals (4-7 days old) is advantageously thinner and is considered as an alternative to that from adult animals. Here, the structures of adult and neonatal bovine pericardium tissues fixed with glutaraldehyde are characterized by synchrotron-based small angle X-ray scattering (SAXS) and compared with the mechanical properties of these materials. Significant differences are observed between adult and neonatal tissue. The glutaraldehyde fixed neonatal tissue has a higher modulus of elasticity (83.7 MPa) than adult pericardium (33.5 MPa) and a higher normalised ultimate tensile strength (32.9 MPa) than adult pericardium (19.1 MPa). Measured edge on to the tissue, the collagen in neonatal pericardium is significantly more aligned (orientation index (OI) 0.78) than that in adult pericardium (OI 0.62). There is no difference in the fibril diameter between neonatal and adult pericardium. It is shown that high alignment in the plane of the tissue provides the mechanism for the increased strength of the neonatal material. The superior strength of neonatal compared with adult tissue supports the use of neonatal bovine pericardium in heterografts.
authors.affiliation: School of Engineering and Advanced Technology, Massey University, Palmerston North 4472, New Zealand.
authors.forename: Katie H
authors.initials: KH
authors.lastname: Sizeland
authors.affiliation: School of Engineering and Advanced Technology, Massey University, Palmerston North 4472, New Zealand.
authors.forename: Hannah C
authors.initials: HC
authors.lastname: Wells
authors.affiliation: Southern Lights Biomaterials, Palmerston North 4110, New Zealand.
authors.forename: John
authors.initials: J
authors.lastname: Higgins
authors.affiliation: Structural Heart Division, Boston Scientific, Los Gatos, CA 95032, USA.
authors.forename: Crystal M
authors.initials: CM
authors.lastname: Cunanan
authors.affiliation: Australian Synchrotron, Clayton, VIC 3168, Australia.
authors.forename: Nigel
authors.initials: N
authors.lastname: Kirby
authors.affiliation: Australian Synchrotron, Clayton, VIC 3168, Australia.
authors.forename: Adrian
authors.initials: A
authors.lastname: Hawley
authors.affiliation: Australian Synchrotron, Clayton, VIC 3168, Australia.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Mudie
authors.affiliation: School of Engineering and Advanced Technology, Massey University, Palmerston North 4472, New Zealand.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Haverkamp
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006348:Cardiac Surgical Procedures; D002417:Cattle; D003094:Collagen / Q000378:metabolism* / Q000648:ultrastructure; D005976:Glutaral / Q000737:chemistry; D006351:Heart Valves / Q000378:metabolism / Q000637:transplantation / Q000648:ultrastructure*; D010496:Pericardium / Q000473:pathology / Q000637:transplantation / Q000648:ultrastructure*; D053838:Scattering, Small Angle; D016707:Tissue Fixation; D014961:X-Ray Diffraction
chemical_list: D003094:Collagen; D005976:Glutaral