A MECHANICAL MODEL FOR THE FORMATION OF VASCULAR NETWORKS IN-VITRO

Endothelial cells, when cultured on gelled basement membrane matrix ex ert forces of tension through which they deform the matrix and at the same time they aggregate into clusters. The cells eventually form a ne twork of cord-like structures connecting cell aggregates. In this netw ork, almost all of the matrix has been pulled underneath the cell cord s and cell clusters. This phenomenon has been proposed as a possible m odel for the growth and development of planar vascular systems in vitr o. Our hypothesis is that the matrix is reorganized and the cellular n etworks form as a result of traction forces exerted by the cells on th e matrix and the latter's elasticity. We construct and analyze a mathe matical model based on this hypothesis and examine conditions necessar y for the formation of the pattern. We show cell migration is not nece ssary for pattern formation and that isotropic, strains-stimulated tra ction is sufficient to form the observed patterns.