Recovery of Passaged Cells Through the Recapitulation of the Pericellular Matrix

In order to create successful cartilage tissue engineered constructs, an abundant supply of healthy cartilage cells (chondrocytes) are required. Since only a small amount can be excised from a patient, chondrocytes must be expanded and passaged in vitro to reach the desired population numbers. As chondrocytes are expanded in vitro they start to lose their chondrogenic phenotype and synthesize less cartilaginous extracellular matrix (ECM); including a pericellular matrix (PCM). A promising method used to upregulate the synthesis of ECM constituents is mechanical stimulation. The objective of this study was to recover the PCM of passaged chondrocytes and determine whether mechanical stimuli could restore their phenotype and function. Although the passaged chondrocytes did not show an increase in cartilaginous ECM accumulation over the long-term culture, they did show a positive response to mechanical stimulation, highlighting the importance of the PCM in maintaining chondrocyte phenotype and mechanosensitivity.