Chondrocyte recovery in cryopreserved porcine articular cartilage after bone carrier alteration

In order to investigate the consequences on the distribution of cell recovery through a cross-section of articular cartilage, the pathway for ice nucleation and diffusion of water and solutes in porcine osteochondral tissue was altered by drilling a 2mm diameter hole through the subchondral bone to the base of the cartilage. Samples equilibrated with 1M dimethyl sulfoxide were cooled at 1 C/min to -30 degrees C then stored in liquid nitrogen. A significant increase in chondrocyte recovery was documented when compared to samples cryopreserved without holes (48.3 percent vs 28.6 percent, P=0.003). The most significant change due to bone base modification was an increase in recovery in the middle section of the cartilage. These results provide insight into mechanisms of cryoinjury in tissue systems.