Abstract
The knee meniscus, a complex fibrocartilaginous structure, is essential for load distribution, joint stability, and lubrication. Despite significant research, aspects of meniscal function and pathology remain unclear. Meniscal injuries and degeneration are common due to limited blood supply, highlighting the need for studies focused on developing tissue-engineered substitutes and drug-delivery therapies. Understanding meniscal mechanics and transport properties is critical for advancing these therapeutic approaches.
The meniscus structure primarily consists of circumferential collagen fibers, surrounded by a disorganized network on the femoral and tibial surfaces. These variations affect biomechanics and transport properties, informing insights into function, disease, and treatment. Integrating transport and biomechanics studies enables researchers to assess how compression impacts diffusion, while computational models assist in characterizing tissue behavior to support research and clinical applications.
Shear tests on porcine menisci examined viscoelastic properties, showing a correlation between high water content and low shear modulus. The femoral surface exhibited the lowest shear modulus, potentially explaining its greater susceptibility to tears.
Transport studies using a custom FRAP protocol measured diffusivity and partitioning. Results indicated that both properties decreased with larger solutes, impacted by extracellular matrix (ECM) hindrance. Tests on mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs), a promising therapeutic tool, showed similar trends but were unaffected by tissue variation, likely due to ECM affinity. Compressive strain reduced diffusivity by up to 45% without altering anisotropic diffusion ratios.
Finally, computational modeling effectively characterized ECM damage, enhancing our understanding of meniscal structure, mechanics, and transport. This research supports strategies in tissue engineering and treatment for meniscal repair and regeneration.