Strengthening of fibrous tissues under mechanical stimuli (in vitro experiments)

The effects of mechanical stimuli on fibroblasts have been investigated, us ing the collagen gel culture method. A specimen of thin collagen gel membra ne, involving cells, was supported by stainless steel wire mesh and subject ed to static or dynamic uniaxial tensile/compressive load in an incubator. The cell alignment, the shrinkage of collagen gel matrix, and mechanical pr operties of the specimens have been examined. We found that both of static and dynamic loads strengthened the collagen matrix. From the morphological evidences, the dynamic stimuli were concluded to be effective in matrix str engthening. However, since the specimens were not strengthened uniformly an d portions of compressive stresses remained weak, the macroscopic tensile t est failed to show the differences of the mechanical properties between the specimens under static and dynamic stimuli.