Aim: The aim of this study was to investigate whether viable chondrocytes can be isolated and subsequently expanded in culture, from cryopreserved intact human articular cartilage.

Method: Human articular cartilage samples, retrieved from patient undergoing total knee replacement, were cored as 5 mm diameter discs then minced to approximately 0.1 mm³ size pieces. Samples were cryopreserved at the following stages; intact cartilage discs, minced cartilage and chondrocytes immediately after enzymatic isolation. After completing of isolation, cell viability was examined using LIVE/DEAD fluorescent staining. Isolated chondrocytes were then cultured and a cell proliferation assay was performed at day 4, 7, 14, 21 and 28 days.

Results: The results showed that the viability of isolated chondrocytes from control, cryopreserved intact AC discs, minced AC and isolated then frozen samples were 71.84 ± 2.63%, 25.61 ± 2.41%, 31.32 ± 2.47 % and 42.53 ± 4.66% respectively. Isolated chondrocytes from all groups were expanded by following degrees after 28 days of culture; Group A: 10 times, Group B: 18 times, Group C: 106 times, and Group D: 154 times.

Conclusion: We conclude that viable chondrocytes can be isolated from cryopreserved intact human AC and then cultured to expand their number. This method could be employed to patients benefit undergoing autologous chondrocyte implantation.

Macrophages and their fused products are commonly found at the polymethylmethacrylate cement-bone interface, but it is not known if they contribute directly to the osteolysis associated with loosening of the cemented prosthesis. We isolated mononuclear phagocytes from granulomas formed by subcutaneous implantation of polymethylmethacrylate into mice and incubated them on bone slices in which they formed resorption lacunae after co-culture for seven to 14 days with both marrow stromal cells and osteoblast-like cells (in the presence of 1 alpha,25-dihydroxyvitamin D3 and dexamethasone). Increased numbers of tartrate-resistant acid phosphatase-positive mononuclear and multinucleated cells formed in these cultures. Both in the presence and absence of stromal cells, macrophages produced extensive superficial roughening of the bone surface. Polymethylmethacrylate-induced macrophages are thus capable of low-grade surface and high-grade lacunar osteolysis, the latter requiring the presence of specific hormonal and stromal cell elements. These two forms of bone resorption could account for the pathogenesis and clinical patterns associated with loosening of the cemented prosthesis.