Perfusion and cyclic compression of mesenchymal cell-loaded and clinically applicable osteochondral grafts.

Osteochondral lesions are often seen in orthopedics, but the available treatment strategies are limited in success. Regenerative medicine provides novel concepts for curing them. The purpose of this study was to test the effects of perfusion and cyclic compression on cell differentiation and mechanical properties using a custom-made biomechanoreactor in a recently established system of human bone marrow stromal cells (hBMSC) cultured in a 3-D collagen I-bone hybrid matrix out of commercially available and separately in human-certified products. Seeded hBMSC were viable for 88 +/- 8.9% during the entire experimental period in the constructs. GAG and DNA levels did not change. Perfusion induced collagen II and cyclic compression increased collagen X expression. Matrix stiffness was significantly increased after 28 days of cyclic compression. Cyclic compression of cell-loaded hybrid constructs enhanced chondrocyte differentiation and matrix stiffness. This system is a promising tool with a view to a later clinical application.