Role of the extracellular matrix in morphogenesis.

The extracellular matrix is a complex, dynamic and critical component of all tissues. It functions as a scaffold for tissue morphogenesis, provides cues for cell proliferation and differentiation, promotes the maintenance of differentiated tissues and enhances the repair response after injury. Various amounts and types of collagens, adhesion molecules, proteoglycans, growth factors and cytokines or chemokines are present in the tissue- and temporal-specific extracellular matrices. Tissue morphogenesis is mediated by multiple extracellular matrix components and by multiple active sites on some of these components. Biologically active extracellular matrix components may have use in tissue repair, regeneration and engineering, and in programming stem cells for tissue replacement.