ABSTRACT
This chapter summarizes experimental data showing the role of some cell-matrix interactions, cell orientation patterns, and mechanical factors in the formation of spatial orientation of different matrix constituents. Polarization and electron microscopic investigations revealed orientation patterns of some extracellular matrix (ECM) constituents. The following patterns proved to be constant ultrastructural features of different embryonic and postembryonic connective tissues: sulfated glycosarninoglycans (GAGs) and collagen fibrils are oriented parallel to each other if they are in interaction with each other, and both sulfated GAGs and collagen are tangentially arranged in the vicinity of the cell membrane. The chapter shows that the following factors might be involved in formation and maintenance of the oriented microstructural patterns in the ECM: cell-matrix interactions; cell shape and orientation of cells and cell groups; interactions of matrix constituents with each other; and mechanical factors. Collagen gels made from soluble collagen are widely used in tissue culture laboratories.
