Chondrocytes from patients with osteoarthritis express typical extracellular matrix molecules once grown onto a...

The opportunity to apply autologous chondrocyte transplantation in repairing cartilage lesions in osteoarthritis (OA) is of great interest. To this end, chondrocytes from cartilage of these patients and from healthy donors were used to evaluate the expression of some extracellular matrix molecules once these cells were grown onto a hyaluronan-based scaffold already used in clinical practice. Constructs were analyzed by immunohistochemical and real-time PCR analyses. Chondrocytes from control and patients with OA cartilages expressed the same extracellular matrix molecules even if at different amount. These differences, which were appreciable both at protein and molecular levels, were not evident once the cells were grown onto Hyaff-11 scaffold. In this experimental culture condition, the cells derived from control and patients with OA showed a significant increase of collagen type II, Sox-9, and aggrecan and a decrease of collagen type I compared with chondrocytes grown in monolayer. On the other hand, MMPs were downregulated in both the cell types evaluated by the specific action of TIMP-1 which was highly expressed at molecular and protein levels in the two groups. The growth of chondrocytes onto Hyaff-11 membrane seems to erase the differences between the cells derived from normal and OA cartilages. The cells seem to benefit of the "hyaluronan" presence which is able to create an ideal environment for the expression of cartilage genes even in absence of specific growth factors. This is of particular relevance hypothesizing the use of tissue engineering therapeutical approach also in patients with OA.