Micromechanical properties of chondrocytes and chondrons: Relevance to articular cartilage tissue engineering

Abstract

Articular cartilage is a highly mechanical tissue, performing multiple functions to ensure proper joint movement. Degradation of this tissue may be due to improper loading conditions that lead to a debilitating condition known as osteoarthritis. Furthermore, it is believed that mechanical signals transmitted from the tissue to cellular levels are necessary for the production of essential extracellular matrix components responsible for cartilage viability. Examinations of the tissue on its most rudimentary level elucidate mechanical regimens related to cartilage health and disease. A fundamental unit approach has been employed to study the biomechanical properties of single cells with discrete pericellular and extracellular matrix layers. This approach enables researchers to develop definitive relationships between mechanical stimulation and changes in gene expression corresponding to regenerative or catabolic processes. The knowledge gained from these studies sheds light on the etiology of osteoarthritis and elucidate the mechanical loading regimens useful for promoting articular cartilage health. This review article discusses the micromechanical environment of the cartilage cell, the chondrocyte, and the mechanical models and experimental techniques utilized to examine its physical characteristics. This information is then related to changes in cellular behavior and its potential toward tissue engineering of articular cartilage.