The main objective of Professor Athanasiou’s research is to understand and enhance the healing processes of cartilage. Indeed, successful cartilage regeneration continues to be the most vexing problem in musculoskeletal medicine. Following trauma (such as sports injuries) or pathologic affliction (such as osteoarthritis), cartilage is unable to heal itself in a way that would allow it to function properly under its strenuous and biomechanically difficult environment.
Of particular interest in our efforts are 1) hyaline articular cartilage, found in diarthrodial joints such as the knee, hip, and shoulder, 2) menisci, in the knee and temporomandibular joint (TMJ), and 3) fibrocartilage in the TMJ. Our approach entails the use of biodegradable scaffolds designed to incorporate suitable bioactive agents and signals to regenerate cartilage. We also place particular emphasis on certain aspects of scaffold design and overall approach. These include 1) biomechanical characterization of cartilage, 2) cell adhesion to substrata, and 3) attachment and effects of growth factors on chondrocytes.
In terms of cartilage biomechanics, we perform topographical characterizations of articulating surfaces using compressive indentation loading and tensile testing. To this end, we use custom-made instruments which allow us to obtain these tissues’ viscoelastic properties. We also develop biomechanical approaches to quantify cartilage structural integrity in vivo and arthroscopically. One of the main issues in scaffold design is to encourage cells to adhere correctly. A significant portion of our efforts centers around the elucidation of mechanisms of cell adhesion, defined as cell attachment, cell spreading, organization of actin cytoskeleton, and formation of focal adhesions. We use cytomechanical techniques to measure the mechanical adhesiveness and mechanical properties of individual cells as a function of peptide substrata. We believe that a deeper understanding and control of cell adhesion will result in better tissue engineered cartilage.