Mansoor Haider, Department of Mathematics, North Carolina State University

Multiphasic models of cell-matrix interactions in articular cartilage

Friday October 26th, 4pm, Phillips 332
(refreshments served in Phillips 330 starting at 3:30)

Abstract: Articular cartilage is the primary load-bearing soft tissue in diarthrodial joints such as the knee, shoulder and hip. Cartilage can be modeled as a multiphasic continuum mixture of collagen, (negatively charged) proteoglycan, and interstitial fluid with dissolved ions. Degradation of cartilage leads to osteoarthritis, a painful condition that is associated with aging. In contrast to many other tissues, cartilage is avascular and aneural. Consequently, mechanical and chemical variables in the local environment of its cells (chondrocytes) strongly influence their metabolic activity and, ultimately, the maintenance of tissue structural integrity. In this talk, biphasic (solid-fluid) and triphasic (solid-fluid-ion) models of cell-matrix interactions will be presented. Solutions of micron- scale boundary value and interface problems that model in vitro experiments of cyclic compressive loading and free swelling will be presented. Significance of the mathematical modeling will be discussed in the context of understanding mechanical factors in osteoarthritis and developing tissue engineering strategies for cartilage repair.