Articular cartilage collagen and proteoglycans. Their functional interdependency

By use of an in vitro experimental system which permits the observation at high resolution of articular cartilage in a physiologic condition, its biomechanical response to compression was investigated before and after enzymatic digestion of the proteoglycan components with testicular hyaluronidase. The study provides further insight into the functional interplay between the collagen network and the hydrated proteoglycans. Certain structural features associated with age-related and osteoarthritic changes occurring in vivo in human articular cartilage were mimicked in the compressive response of the enzymatically digested tissue.