Cryopreserved articular chondrocytes grow in culture, maintain cartilage phenotype, and synthesize matrix components

Abstract

For osteochondral allograft transplantation to be successful, chondrocytes must survive preservation and retain their capacity to produce normal matrix components: proteoglycans and Type II collagen. Clinical success with osteochondral allograft transplantation has created an increased demand for supplies of suitable cartilage-bearing grafts. This demand has stimulated attempts to find successful methods for low temperature storage of cartilage for “banking” and heightened interest in cartilage cryobiology. In order to achieve the maximum viability of cryopreserved articular cartilage, previous comprehensive studies have focused on rates and temperatures of freezing, cryoprotective agents, and methods and influences of thawing. This study presents evidence that cryopreserved articular chondrocytes maintain their ability to grow in tissue culture following thawing and to produce normal matrix components. Chondrocytes isolated from Japanese white rabbits were divided into groups of fresh controls and experimental cryopreserved cells. Cells were incubated in dimethylsulfoxide, frozen at a rate of −1°C/min, stored at −79°C, rapidly thawed, and plated for culture, Growth rates were comparable in all groups. In all groups, typical chondroid characteristics were maintained throughout 14 days of culture. Typical cartilage phenotypic characteristics included maintenance of polygonal and rhomboidal cells, cell aggregation, proteoglycan production, and Type II collagen synthesis. This investigation strongly indicates that articular chondrocyte cryopreservation yields viable, functional cells and although these results cannot be directly extrapolated to intact adult articular cartilage, they do give further support for low temperature banking of cartilage-bearing allografts for transplantation.