Tissue morphogenesis is the process by which the form of the body and its various organs are established in the embryo, and by which normal and abnormal changes in the adult, such as wound healing and tumor invasion, are brought about. Dr. Newman and Dr. Forgacs propose to conduct interdisciplinary studies on the physical mechanism of "matrix-driven translocation", and adhesive interaction between particles or cells and extracellular macromolecules that resembles tissue morphogenesis in several respects. The movement of particles in this experimental system will be analyzed in terms of the physical theories of "wetting" and "percolation". They proposed that cells or particles and collagen fibers can form percolation networks, which constitute distinct physical phases. These phases can then spread along, or interpenetrate between, other phases or substrata. These ideas may account for certain fundamental properties of tissues. By manipulating various parameters in the matrix-driven translocation assay, such as particle concentration and size, and collagen concentration, these concepts can be tested in a manner not feasible with living tissues. Moreover, by studying mathematical models of systems that exhibit percolative and wetting behavior, they can assess the adequacy of these ideas to explain various properties and behaviors of tissues. %%% Tissue morphogenesis is a complex phenomenon involving cell movements resulting ultimately in the final form of the adult organism. Drs. Newman and Forgacs have attempted to isolate and characterize a subset of these complex processes in a model system that mimics some of the behavior of migrating cells. They will study this model in an attempt to gain some insight into the more complex phenomena of cell migration during embryogenesis
