Dynamics of Cryoprotectant Permeation in Porcine Heart Valve Leaflets
Source: Cell Transplantation, Volume 12, Number 2, 2003 , pp. 123-128(6)
Publisher: Cognizant Communication Corporation
Abstract:Valve replacement is a common cardiovascular procedure for the treatment of a variety of congenital and acquired defects. Many surgical programs rely on cryopreserved heart valves from regional tissue bank programs to meet clinical demands. Current cryopreservation strategies for heart valves are empirically derived. The aim of this study was to use proton nuclear magnetic resonance spectroscopy (NMR) to monitor changes in cryoprotectant concentration in isolated heart valve leaflets. Porcine aortic valves were locally obtained, freshly isolated, and allowed to equilibrate at various experimental temperatures (22°C, 10°C, 4°C) for 1 h prior to immersion in 1 M Me2SO solution. At defined intervals (0, 0.25, 0.5, 1, 2, 6, and 24 h) the valves were removed from the Me2SO and the leaflets were rapidly dissected and equilibrated in deuterium oxide (D2O). Using previously described techniques the Me2SO concentration in the heart valve leaflets was determined by NMR and the diffusion coefficient was calculated as a function of time and temperature. Heart valve leaflets were fully equilibrated with Me2SO after approximately 2 h of exposure at 22°C while equilibrium was not reached >6 h or more at 10°C and 4°C. These results indicate that that permeation of Me2SO in heart valves is strongly temperature dependent. Furthermore, this study provides a quantitative measure of Me2SO permeation and cryoprotectant at equilibration in heart valve leaflets. The clinical applications of these findings may help to optimize the balance between the protective and toxic effects of cryoprotectants and lead to improved methods of preservation of heart valves.
Document Type: Research article
Affiliations: 1: *Surgical-Medical Research Institute, University of Alberta, Edmonton, Canada 2: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada 3: §Protein Engineering Network Centres of Excellence, University of Alberta, Edmonton, Canada 4: Department of Surgery, University of Alberta, Edmonton, Canada
Publication date: 2003-01-01
- Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.