title: Cryopreservation of porcine articular cartilage: MRI and biochemical results after different freezing protocols.
abstract: The objective of this study was to investigate the effects of cryopreservation on the components of articular cartilage (AC) matrix by utilizing magnetic resonance imaging (MRI) and biochemical assessments. Porcine AC (10mm osteochondral dowels) was collected into four groups - (1) phosphate buffered saline (PBS) control, (2) PBS snap frozen in liquid nitrogen, (3) slow-cooled in dimethyl sulfoxide (DMSO), and (4) slow cooled in PBS (in absence of DMSO). MRI results demonstrated three distinct zones in the cartilage. After exposure to ice formation during cryopreservation procedures, alterations in MRI determined matrix fixed charged density and magnetization transfer rate were noted. In addition, biochemical assays demonstrated significant alterations in chondroitin sulfate and hydroxyproline content over time without differences in hydration or DNA content. In conclusion, MRI was able to detect some changes in the intact cartilage matrix structure consistent with biochemical assessments after ice formation during cryopreservation of intact porcine AC. Furthermore, biochemical assessments supported some of these findings and changed significantly after incubating the cartilage matrix for 36-72 h in PBS in terms of chondroitin sulfate and hydroxyproline content.
authors.affiliation: 2D2.32 WMC, Department of Surgery, University of Alberta Hospital, 8440-112St Edmonton, Alta., Canada T6G 2B7.
authors.forename: Leila
authors.initials: L
authors.lastname: Laouar
authors.forename: Ken
authors.initials: K
authors.lastname: Fishbein
authors.forename: Locksley E
authors.initials: LE
authors.lastname: McGann
authors.forename: Walter E
authors.initials: WE
authors.lastname: Horton
authors.forename: Richard G
authors.initials: RG
authors.lastname: Spencer
authors.forename: Nadr M
authors.initials: NM
authors.lastname: Jomha
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000033:anatomy & histology / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000378:metabolism; D015925:Cryopreservation / Q000379:methods*; D005615:Freezing; D006909:Hydroxyproline / Q000378:metabolism; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D013552:Swine
chemical_list: D002809:Chondroitin Sulfates; D006909:Hydroxyproline