title: Permeation of several cryoprotectant agents into porcine articular cartilage.
abstract: OBJECTIVE
  Osteochondral allografting is an effective method to treat large osteochondral defects but difficulties in tissue preservation have significantly limited the application of this technique. Successful cryopreservation of articular cartilage (AC) could improve the clinical availability of osteochondral tissue and enhance clinical outcomes but cryopreservation of large tissues is hampered by a lack of knowledge of permeation kinetics within these tissues. This study describes the refinement and extension of a recently published technique to measure the permeation kinetics of cryoprotectant agents (CPAs) within porcine AC.
  
  
  METHODS
  Dowels of porcine AC (10mm diameter) were immersed in solutions containing 6.5 M concentrations of four commonly used CPAs [dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG) and glycerol] for different times (1s, 1, 2, 5, 10, 15, 30, 60, 120, 180 min , 24h) at three different temperatures (4, 22, and 37 degrees C). The cartilage was isolated and the amount of CPA within the matrix was determined.
  
  
  RESULTS
  Diffusion coefficients (DMSO=2.4-6.2x10(-6)cm2/s; PG=0.8-2.7x10(-6)cm2/s; EG=1.7-4.2x10(-6)cm2/s; and glycerol=0.8-2.4x10(-6)cm2/s) and activation energies (DMSO=4.33 kcal/mol, PG=6.29 kcal/mol, EG=3.77 kcal/mol, and glycerol=5.56 kcal/mol) were determined for each CPA.
  
  
  CONCLUSIONS
  The results of this experiment provide accurate permeation kinetics of four commonly used CPAs in porcine articular cartilage. This information will be useful for developing effective vitrification protocols for cryopreservation of AC.
authors.affiliation: Department of Surgery, University of Alberta Hospital, 2D2.32 WMC, University of Alberta, 8440-112St Edmonton, Alta., Canada T6G 2B7. Electronic address: njomha@ualberta.ca.
authors.forename: Nadr M
authors.initials: NM
authors.lastname: Jomha
authors.affiliation: Department of Surgery, University of Alberta Hospital, 2D2.32 WMC, University of Alberta, 8440-112St Edmonton, Alta., Canada T6G 2B7.
authors.forename: Garson K
authors.initials: GK
authors.lastname: Law
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Alireza
authors.initials: A
authors.lastname: Abazari
authors.affiliation: Department of Surgery, University of Alberta Hospital, 2D2.32 WMC, University of Alberta, 8440-112St Edmonton, Alta., Canada T6G 2B7.
authors.forename: Kassim
authors.initials: K
authors.lastname: Rekieh
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada.
authors.forename: Janet A W
authors.initials: JAW
authors.lastname: Elliott
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada.
authors.forename: Locksley E
authors.initials: LE
authors.lastname: McGann
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000737:chemistry / Q000378:metabolism*; D004058:Diffusion; D007700:Kinetics; D010539:Permeability; D013552:Swine; D013696:Temperature
chemical_list: D003451:Cryoprotective Agents