gms | German Medical Science

Objectives: There has long been a lack of effective treatments for osteochondral lesions, a common condition in orthopedics. This work should provide new ideas and clinical strategies for the treatment of large osteochondral lesions in weight-bearing areas in goats and make it possible to form a bionic joint in a laboratory setting.

Methods: In vitro, the bone marrow stromal stem cells (BMSCs) were identified by immunofluorescence staining and flow cytometry with CD90, CD44, CD29, CD45 and CD34. Meanwhile, we did the osteogenesis induction from stem cells, the cell proliferation test by CCK8 kits. Scanning electron microscopy observed adhesion and growth of BMSCs in porous tantalum (pTa) as well as the morphology of chondrocytes on collagen membrane (CM). Then, the mechanism of osteogenesis and chondrogenesis and related signal pathways were interpreted by real-time PCR; In vivo, a novel and biomimetic complex was constructed by BMSCs/porous tantalum associated with chondrocyte/collagen membranes to repair large osteochondral defects in a weight-bearing area. After 16 weeks, goat femoral head samples were taken out for immunohistochemistry and hard tissue sliced.

Results and conclusion: We used porous SiC as a scaffold and prepared a tantalum coating by chemical vapor deposition, whose pore size and porosity are very similar to trabecular. Moreover, the pTa also had sufficient mechanical properties and non-cytotoxicity to support growth of BMSCs, chondrocytes and MG63. The SEM demonstrated that pTa was evenly filled with BMSCs. CM was beneficial to chondrocyte adhesion. A large amount of matrix secretion was visible around chondrocytes. The real-time PCR results showed that the expression of osteogenic genes, such as ALP, OSX, OCN, Collage I and OSN in porous tantalum metal were higher than these in porous titanium alloys. Meanwhile, collagen membrane can promote chondrocyte to secrete Collage II and AGG. In vivo, 16 weeks after implantation, osteochondral defects in almost half of the femoral heads had been successfully repaired by BMSCs/pTa-chondrocytes/CM biphasic scaffold.

In conclusion, the present study demonstrated the potential for clinical transformation of the repair of large osteochondral defects in weight-bearing areas. This work should provide new ideas and strategies for the treatment of large osteochondral lesions in clinical settings.