title: Protein stability in stored decellularized heart valve scaffolds and diffusion kinetics of protective molecules.
abstract: Decellularized tissues can be used as matrix implants. The aims of this study were to investigate protein stability and solvent accessibility in decellularized pulmonary heart valve tissues. Protein denaturation profiles of tissues were studied by differential scanning calorimetry. Protein solvent accessibility of tissue exposed to D2O, and diffusion kinetics of various protective molecules were studied by Fourier transform infrared spectroscopy. Little changes were observed in the protein denaturation temperature during storage, at either 5 or 40°C. Glycerol was found to stabilize proteins; it increased the protein denaturation temperature. The stabilizing effect of glycerol disappeared after washing the sample with saline solution. Hydrogen-to-deuterium exchange rates of protein amide groups were fastest in leaflet tissue, followed by artery and muscle tissue. Diffusion of glycerol was found to be fastest in muscle tissue, followed by artery and leaflet tissue. Diffusion coefficients were derived and used to estimate the time needed to reach saturation. Fixation of tissue with glutaraldehyde had little effects on exchange and diffusion rates. Diffusion rates decreased with increasing molecular size. Proteins in decellularized heart valve tissue are stable during storage. Glycerol increases protein stability in a reversible manner. Solvent accessibility studies of protein amide groups provide an additional tool to study proteins in tissues. Diffusion coefficients can be derived to simulate diffusion kinetics of protective molecules in tissues. This study provides novel tools to evaluate protein stability and solvent accessibility in tissues, which can be used to develop biopreservation strategies.
authors: Institute of Multiphase Processes, Leibniz Universität Hannover, Hannover, Germany.
authors: Shangping
authors: S
authors: Wang
authors: Clinic for Horses - Unit for Reproductive Medicine, University of Veterinary Medicine Hannover, Hannover, Germany.
authors: Harriëtte
authors: H
authors: Oldenhof
authors: Institute of Multiphase Processes, Leibniz Universität Hannover, Hannover, Germany.
authors: Xiaolei
authors: X
authors: Dai
authors: Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School, Hannover, Germany.
authors: Axel
authors: A
authors: Haverich
authors: Leibniz Research Laboratories for Biotechnology and Artificial Organs, Hannover Medical School, Hannover, Germany.
authors: Andres
authors: A
authors: Hilfiker
authors: Corlife GbR, Hannover, Germany.
authors: Michael
authors: M
authors: Harder
authors: Institute of Multiphase Processes, Leibniz Universität Hannover, Hannover, Germany. Electronic address: wolkers@imp.uni-hannover.de.
authors: Willem F
authors: WF
authors: Wolkers
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D019610:Cytoprotection / Q000187:drug effects; D004058:Diffusion; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000494:pharmacology; D006351:Heart Valves / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology; D007700:Kinetics; D011489:Protein Denaturation / Q000187:drug effects; D055550:Protein Stability; D012997:Solvents / Q000494:pharmacology*; D013048:Specimen Handling; D017550:Spectroscopy, Fourier Transform Infrared; D013395:Sucrose / Q000494:pharmacology; D013552:Swine; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D012997:Solvents; D013395:Sucrose; D005947:Glucose; D005990:Glycerol
keywords: ATR; DSC; Diffusion; FTIR; Fourier transform infrared spectroscopy; HES; Matrix implants; Protein stability; Pulmonary heart valve conduits; attenuated total reflection; differential scanning calorimetry; hydroxyethyl starch