Static and dynamic compression modulate matrix metabolism in tissue engineered cartilage.
Static and dynamic compression are known to modulate the metabolism of articular cartilage. The present study focused on determining the effects of compressive loading on the metabolism of sulfated glycosaminoglycans (S-GAG) and protein in tissue engineered cartilage constructs. Cartilage constructs were subjected to static or dynamic compression for 24 h and radiolabeled with 35SO4 and 3H-proline to assess the total synthesis and percentage retention of S-GAG and total protein, respectively. Static compression at an amplitude of 50% suppressed the synthesis of both S-GAG and protein by 35% and 57%, respectively. Dynamic compression at an amplitude of 5% had stimulatory effects on synthesis that were dependent on the static offset compression amplitude (10% or 50%) and dynamic compression frequency (0.001 or 0.1 Hz). Thus, tissue engineered cartilage demonstrated the ability to respond to mechanical loading in a manner similar to that observed with articular cartilage. Mechanical loading may therefore potentially be used to modulate the growth of cartilaginous tissues in vitrd, potentially facilitating the culture of functional cartilage tissues suitable for implantation.