Suitability of porcine chondrocyte micromasses to model osteoarthritis in vitro

Abstract

Purpose: Today, for regenerative treatment of injured or early osteoarthritic cartilage, ACI and MACI are clinically applied. Also mesenchymal stem cell based approaches have reached the clinic. Here, AMICÒ combines microfracture with implantation of a collagen membrane, and ChondrotissueÒ microfracture with a PGA/hyaluronan scaffold. AMICÒ is a passive approach; endogenous MSC flow into the membrane. ChondrotissueÒ, in whose development we were involved, is between passive and active; MSC flow into the scaffold is enhanced by the addition of MSC recruiting serum. Our aim is to develop an active in situ approach, wherein the implantation of scaffolds, loaded with MSC recruiting chemokines and differentiation factors, combined with microfracture, allows the use of endogenous MSC to promote OA cartilage regeneration. Methods: MSC were isolated from bone marrow of normal donor and OA hip joint cancellous bone and characterized (morphology, growth, surface marker, multilineage potential). Also their Ck receptor profile was elucidated (qPCR, immunohistochemistry). Cartilage and chondrocytes were harvested from ND and OA femoral heads, and supernatants were analyzed for their Ck profile (protein array). Then, the recruitment potential of supernatants and Ck on MSC was examined (chemotaxis assay), and Pertussis toxin, siRNA and antibodies were applied to block Ck receptors. Moreover, expression profiles of Ck