Engineering biomechanically functional neocartilage derived from expanded articular chondrocytes through the manipulation of cell‐seeding density and dexamethasone concentration |
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| Authors: | Brian J. Huang Daniel J. Huey Jerry C. Hu Kyriacos A. Athanasiou |
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| Affiliation: | 1. Department of Biomedical Engineering, University of California, Davis, CA, USA;2. Department of Orthopedic Surgery, University of California, Davis, CA, USA |
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| Abstract: | Recent work has established methods to engineer self‐assembled, scaffold‐free neocartilage from an expanded articular chondrocyte (AC) cell source. In continuing such work, the objective of the present study was to investigate the effects of cell‐seeding density and dexamethasone concentration on these neocartilage constructs. Neocartilage discs (5 mm diameter) were formed by self‐assembling passaged leporine articular chondrocytes into non‐adherent agarose moulds. The cell‐seeding densities (2, 3, 4, 5 and 6 million cells/construct) and dexamethasone concentrations (10 and 100 nm ) in the culture medium were varied in a full‐factorial study. After 4 weeks, the neocartilage constructs were assessed for morphological, biochemical and biomechanical properties. The cell‐seeding density profoundly affected neocartilage properties. The two dexamethasone concentrations explored did not induce overall significant differences. Constructs formed using lower cell‐seeding densities possessed much higher biochemical and biomechanical properties than constructs seeded with higher cell densities. Notably, the 2 million cells/construct group formed hyaline‐like neocartilage with a collagen wet weight (WW) content of ~7% and a Young's modulus of ~4 MPa, representing the high end of values achieved in self‐assembled neocartilage. Excitingly, the mechanical properties of these constructs were on a par with that of native cartilage tissues tested under similar conditions. Through optimization of cell‐seeding density, this study shows for the first time the use of expanded ACs to form homogeneous self‐assembled neocartilage with exceptionally high tensile strength. With such functional properties, these engineered neocartilage constructs provide a promising alternative for treating articular lesions. Copyright © 2016 John Wiley & Sons, Ltd. |
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| Keywords: | cell density dexamethasone cartilage tissue engineering juvenile chondrocytes cartilage repair hyaline cartilage neocartilage |
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