title: The effects of anticalcification treatments and hydration on the molecular dynamics of bovine pericardium collagen as revealed by 13C solid-state NMR.
abstract: This article describes a solid-state NMR (SSNMR) investigation of the influence of hydration and chemical cross-linking on the molecular dynamics of the constituents of the bovine pericardium (BP) tissues and its relation to the mechanical properties of the tissue. Samples of natural phenethylamine-diepoxide (DE)- and glutaraldehyde (GL)-fixed BP were investigated by (13)C cross-polarization SSNMR to probe the dynamics of the collagen, and the results were correlated to the mechanical properties of the tissues, probed by dynamical mechanical analysis. For samples of natural BP, the NMR results show that the higher the hydration level the more pronounced the molecular dynamics of the collagen backbone and sidechains, decreasing the tissue's elastic modulus. In contrast, in DE- and GL-treated samples, the collagen molecules are more rigid, and the hydration seems to be less effective in increasing the collagen molecular dynamics and reducing the mechanical strength of the samples. This is mostly attributed to the presence of cross-links between the collagen plates, which renders the collagen mobility less dependent on the water absorption in chemically treated samples.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970 São Carlos, SP, Brazil. azevedo@ifsc.usp.br
authors.forename: E R
authors.initials: ER
authors.lastname: deAzevedo
authors.forename: A M I B
authors.initials: AM
authors.lastname: Ayrosa
authors.forename: G C
authors.initials: GC
authors.lastname: Faria
authors.forename: H J
authors.initials: HJ
authors.lastname: Cervantes
authors.forename: D
authors.initials: D
authors.lastname: Huster
authors.forename: T J
authors.initials: TJ
authors.lastname: Bonagamba
authors.forename: R N M
authors.initials: RN
authors.lastname: Pitombo
authors.forename: S R
authors.initials: SR
authors.lastname: Rabbani
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D010496:Pericardium / Q000737:chemistry*; D012015:Reference Standards
chemical_list: D002247:Carbon Isotopes; D003094:Collagen