Morphogenesis and Tissue Engineering

Morphogenesis is the developmental cascade of pattern formation and body plan establishment, culminating in the adult form. It is the basis for the emerging discipline of tissue engineering. This exciting field is based on principles of molecular development biology and morphogenesis, gleaned through studies of inductive signals, responding stem cells, and the extracellular matrix scaffolds, which are used to design and construct spare parts to restore function to the human body. Among the many organs in the body, bone has considerable powers for regeneration and is a prototype model for tissue engineering. Implantation of demineralized bone matrix into subcutaneous sites results in local bone induction. This model mimics the steps sequential bone morphogenesis and has permitted the isolation of bone morphogens, such as bone morphogenetic proteins (BMPs). BMPs are also involved in the morphogenesis of cartilage and other organs. The symbiosis of the mechanisms underlying bone induction and differentiation is critical for tissue engineering and is governed by both biomechanics (physical forces) and context (microenvironment/extracellular matrix scaffold), which can be duplicated by biomimetic biomaterials such as collagens, hydroxyapatite, proteoglycans, and cell adhesion glycoproteins, including fibronectins and laminin. Rules of tissue architecture elucidated in bone morphogenesis may provide insights into tissue engineering of bone and cartilage and be universally applicable to other organs/tissues, including the entire joints in the musculoskeletal system.