Inhomogeneous Response of Articular Cartilage: A Three-Dimensional Multiphasic Heterogeneous Study

PLoS One. 2016 Jun 21;11(6):e0157967. doi: 10.1371/journal.pone.0157967. eCollection 2016.

Abstract

Articular cartilage exhibits complex mechano-electrochemical behaviour due to its anisotropy, inhomogeneity and material non-linearity. In this work, the thickness and radial dependence of cartilage properties are incorporated into a 3D mechano-electrochemical model to explore the relevance of heterogeneity in the behaviour of the tissue. The model considers four essential phenomena: (i) osmotic pressure, (ii) convective and diffusive processes, (iii) chemical expansion and (iv) three-dimensional through-the-thickness heterogeneity of the tissue. The need to consider heterogeneity in computational simulations of cartilage behaviour and in manufacturing biomaterials mimicking this tissue is discussed. To this end, healthy tibial plateaus from pigs were mechanically and biochemically tested in-vitro. Heterogeneous properties were included in the mechano-electrochemical computational model to simulate tissue swelling. The simulation results demonstrated that swelling of the heterogeneous samples was significantly lower than swelling under homogeneous and isotropic conditions. Furthermore, there was a significant reduction in the flux of water and ions in the former samples. In conclusion, the computational model presented here can be considered as a valuable tool for predicting how the variation of cartilage properties affects its behaviour, opening up possibilities for exploring the requirements of cartilage-mimicking biomaterials for tissue engineering. Besides, the model also allows the establishment of behavioural patterns of swelling and of water and ion fluxes in articular cartilage.

MeSH terms

  • Animals
  • Cartilage, Articular / physiology*
  • Cations
  • Elastic Modulus
  • Imaging, Three-Dimensional*
  • Joints / physiology
  • Models, Theoretical
  • Numerical Analysis, Computer-Assisted
  • Permeability
  • Sus scrofa
  • Tibia / physiology

Substances

  • Cations

Grants and funding

This work was supported by The Spanish Ministry of Economy and Competitiveness (MINECO), https://sede.micinn.gob.es/, MAT2013-46467-C4-3-R, to MHD; The Spanish Ministry of Economy and Competitiveness (MINECO), https://sede.micinn.gob.es/, FPU graduate research program AP2010/2557, to SM; The Government of Aragon (DGA), to MHD; Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), http://www.ciber-bbn.es/es/quienes-somos, to MHD; and the Nuffield Orthopaedic Centre NIHR Biomedical Research Unit funding and Orthopaedic Research of UK (ORUK), http://www.ndorms.ox.ac.uk/about/contact-us, to MA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.