Improved Knee Cartilage Models Could Aid in Treatments
This engineered tissue replicates key features of degenerating tissue and can serve as a platform from which to test new physical therapy treatments or drug-based treatment strategies.
Fibrocartilage tissue in the knee consists of a more varied molecular structure than was previously realized, according to research published in Nature Materials.
This work, conducted by researchers at the University of Delaware and the Perelman School of Medicine at the University of Pennsylvania, informs ways to better treat injuries such as knee meniscus tears.
The development of effective treatment strategies to address pathologies of fibrocartillaginous tissue has been hindered by an incomplete understanding of the interplay between structure and function, as well as how cells within these tissues respond to mechanical inputs such as walking, running, and other physical activity.
Tissue-engineered models exist and can mimic aspects of healthy tissue structure and function, but they do not stimulate early tissue degeneration.
"To be able to probe natural tissue structure-function relationships, we developed micro-engineered models to advance our understanding of tissue development, homeostasis, degeneration, and regeneration in a more controlled manner," Robert Mauck, PhD, an associate professor of Orthopaedic Surgery and Bioengineering at the University of Pennsylvania, said in a statement. "Our tissue-engineered constructs match the structural, mechanical, and biological properties of native tissue during the process of tissue formation and degeneration."
He added: "Essentially, we are working to engineer tissues not just to provide healthy replacements, but also to better understand what is happening to cause degeneration in the first place."
Meniscus tissues of knees are comprised of fibrous regions that have long, aligned fibers that give the tissue strength and stiffness. Within this fibrous region are small non-fibrous regions called microdomains that have a different composition and correspondingly different mechanical properties. Even though the fibrous regions transmit mechanical deformation signals to surrounding cells, the microdomains do not deform.