title: Changes in denaturation and rheological properties of collagen-hyaluronic acid scaffolds as a result of temperature dependencies.
abstract: This report describes the effect of temperature on the mechanical viscoelastic properties such as: storage modulus (E'), loss modulus (E''), and loss tangent (tandelta) of the collagen sponges modified with hyaluronic acid (HA). In order to detect collagen-HA copolymer denaturation and to assess its thermal stability, the differential scanning calorimetry (DSC) supplemented by thermogravimetric (TG) measurements was used. The denaturation temperature (T(d)) of unmodified collagen samples increased from 69 to 86 degrees C for cross-linked samples, respectively. These temperature dependencies show remarkable changes in E' and E'' at selected temperature up to 226 degrees C for all samples due to the release of loosely and strongly bound water. The influence of HA on the viscoelastic behavior of collagen is manifested by a shift of the tandelta peak associated with the process of decomposition towards higher temperatures resulting in a higher thermo-stability of the modified scaffolds.
authors.affiliation: Institute of Polymer & Dye Technology, Technical University of Łódź, Chemistry Department, Stefanowskiego 12/16, 90-924 Łódź, Poland. krystp@p.lodz.pl
authors.forename: Krystyna
authors.initials: K
authors.lastname: Pietrucha
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002152:Calorimetry, Differential Scanning; D024042:Collagen Type I / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D006358:Hot Temperature; D006820:Hyaluronic Acid / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008956:Models, Chemical; D008968:Molecular Conformation; D010434:Pepsin A / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013552:Swine; D013696:Temperature; D013710:Tendons / Q000378:metabolism; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
chemical_list: D024042:Collagen Type I; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D011108:Polymers; D014867:Water; D006820:Hyaluronic Acid; D010434:Pepsin A