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

Area of Science:

• Biomedical Engineering
• Tissue Mechanics
• Computational Biology

Background:

• Articular cartilage exhibits complex mechano-electrochemical behavior due to anisotropy, inhomogeneity, and non-linearity.
• Understanding tissue heterogeneity is crucial for accurate simulations and biomaterial design.

Purpose of the Study:

• To incorporate thickness and radial dependence of cartilage properties into a 3D mechano-electrochemical model.
• To explore the relevance of heterogeneity in articular cartilage behavior.
• To investigate the impact of heterogeneity on tissue swelling and fluid/ion transport.

Main Methods:

• Developed a 3D mechano-electrochemical model accounting for osmotic pressure, convective/diffusive processes, chemical expansion, and through-the-thickness heterogeneity.
• Mechanically and biochemically tested in-vitro healthy porcine tibial plateaus.
• Integrated heterogeneous properties into the computational model to simulate tissue swelling.

Main Results:

• Simulations showed significantly lower swelling in heterogeneous cartilage samples compared to homogeneous/isotropic conditions.
• A significant reduction in water and ion flux was observed in heterogeneous samples.
• The model successfully predicted reduced swelling and altered transport due to heterogeneity.

Conclusions:

• Heterogeneity significantly influences articular cartilage behavior, reducing swelling and transport.
• The developed computational model is a valuable tool for predicting cartilage behavior and guiding biomaterial design for tissue engineering.
• The model aids in understanding swelling patterns and water/ion fluxes in articular cartilage.