Acceleration of experimental endochondral ossification by biophysical stimulation of the progenitor cell pool.

Endochondral ossification can be modulated by a number of biochemical and biophysical stimuli. This study uses the experimental model of decalcified bone matrix-induced endochondral ossification to examine the effect of one biophysical stimulus, an electromagnetic field, on chondrogenesis, calcification, and osteogenesis. A temporal acceleration and quantitative increase in sulfate incorporation, glycosaminoglycan content, and calcification suggests that the stimulation of endochondral ossification is due to an increase in extracellular matrix synthesis. The locus of that stimulation is identified in the mesenchymal stage of endochondral bone development, and stimulation at this stage is essential for accelerated bone formation. The data suggest that enhanced differentiation of mesenchymal stem cells present at this stage is most likely responsible for the increase in extracellular matrix synthesis and bone maturation.