TENSILE BEHAVIOR OF FIBROBLASTS CULTURED IN COLLAGEN GEL

An in vitro morphological study on the relation of the stress field an d the orientation of cells with the use of the time lapse video record ing system was carried out. Specimens of thin collagen gel membrane, w ithin which cells are proliferating, were examined under various mecha nical conditions. Cell stretching, cell orientation, cell migration, c ell proliferation and generation of tensile stress in collagen gel wer e recorded. It was demonstrated that fibroblasts generate tension and change their orientation along the tensile direction. A hypothetical m echanism for such phenomena is proposed, that is, fibroblasts generate tension and make tense collagen fibres, then cells stretch themselves along the tense fibres and increase tension in this direction. Thus, this mechanism works as a positive feedback loop which enables cells t o make tensile stresses and align along them in accordance with the me chanical environment. (C) 1996 Elsevier Science Limited