Munir, Samir3; Søballe, Kjeld4; Ulrich-Vinther, Michael4; Koch, Thomas Gadegaard3
1 Department of Clinical Medicine - The Department of Orthopaedics E, ?AS, Department of Clinical Medicine, Health, Aarhus University2 Department of Clinical Medicine - Ortopædkirurgisk afdeling E, THG, Department of Clinical Medicine, Health, Aarhus University3 Department of Clinical Medicine - The Department of Orthopaedics E, ?AS, Department of Clinical Medicine, Health, Aarhus University4 Department of Clinical Medicine - Ortopædkirurgisk afdeling E, THG, Department of Clinical Medicine, Health, Aarhus University
Background: Articular chondrocytes and bone marrow-derived multipotent mesenchymal stromal cells (MSCs) are the favoured cells for cartilage tissue engineering. Umbilical cord blood has proven an alternative source of MSCs and moreover they may be more potent chondroprogenitor cells than bonemarrow MSCs. Purpose / Aim of Study: Multilineage progenitor cells (MLPCs) are clonal cord blood-derived MSCs and may therefore provide a cell source with more reproducible outcomes compared to heterogeneous primary MSC cultures. Materials and Methods: We evaluated the chondrogenic potency of MLPCs in standard micromass pellet system, layered on calcium polyphosphate (CPP), and on semi-permeable polytetrafluoroethane membranes with and without collagen type I, II or IV pre-coating. Findings / Results: The MPLC cell line used in this study possessed poor chondrogenic potency overall, but membrane culturing resulted in a multicellular layer tissue with formation of more cartilaginous tissue compared to micromass or CPP culture. In the membrane system MLPCs produced pellucid discs, 12 mm in diameter by 1 mm in thickness from 2x10^6 cells. The discs had hyaline-like cartilage extracellular matrix, with 4-fold greater proteoglycan content compared to MLPCs differentiated in standard micromass pellet cultures. The expression of cartilage specific genes for aggrecan, collagen II and SOX9 was significantly increased in uncoated as well as collagen type I and IV coated membrane cultures compared with micromass or CPP cultures. Conclusions: In conclusion, we demonstrate that MLPCs possess’ chondrogenic potency, which increased when cultured scaffold-free on membrane inserts resulting in multicellular-layered hyaline-like cartilage tissue. Evaluating the effect of culturing pre-differentiated MLPCs on CPP is an obvious next step since direct seeding of MLPCs on CPP did not yield satisfactory biphasic constructs.