Effect of osteogenic protein‐1 on the matrix metabolism of bovine tendon cells

Tendon rupture is a common sports injury in adults. However, the mechanical properties of repair tissue are inferior to those of normal tissue. To accelerate tendon healing, an in vivo approach using growth factors has been applied and has shown evidence for the efficacy of biological stimulation of the repair process. Recombinant human osteogenic protein‐1 (rhOP‐1) has been shown to be effective in stimulating matrix production by various connective tissues. To test the effect of rhOP‐1 on the matrix metabolism of tendon cells in vitro, bovine tendon cells were cultured in monolayer with various doses of rhOP‐1 for 7 days. The addition of rhOP‐1 to cell culture media resulted in significant increases in cell proliferation, DNA content, and the synthesis of proteoglycans (PGs) and collagen, compared to control cultures. The relative percentage of large PGs in the OP‐1 culture was higher than that in the control culture. In conclusion, we show for the first time that rhOP‐1 stimulates the proliferation of tendon cells and their ability to synthesize and accumulate PGs and collagen in their extracellular matrix. These biological properties may be used in the tissue‐engineering of tendon tissues. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:42–48, 2008