IGF-I and mechanical environment interact to modulate engineered cartilagedevelopment

Bovine calf articular chondrocytes were seeded onto biodegradable polyglyco lic acid scaffolds and cultured for four weeks using in vitro systems provi ding different mechanical environments (static and mixed Petri dishes, stat ic and mixed flasks, and rotating vessels) and different biochemical enviro nments (medium with and without supplemental insulin-like growth factor I, IGF-I). Under all conditions, the resulting engineered tissue histologicall y resembled cartilage and contained its major constituents: glycosaminoglyc ans, collagen, and cells. The mechanical environment and supplemental IGF-I (a) independently modulated tissue morphology, growth, biochemical composi tion, and mechanical properties (equilibrium modulus) of engineered cartila ge as previously reported; (b) interacted additively or in some cases nonad ditively producing results not suggested by the independent responses, and (c) in combination produced tissue superior to that obtained by modifying t hese factors individually. (C) 2001 Academic Press.