Smart biomaterials and constructs for Bone tissue regeneration

The skeleton contains 99% of the body's calcium and is crucial to maintaining extracellular calcium levels within the very narrow limits essential to life. The primary functions of the skeleton are to provide structural support, maintain calcium homeostasis, and replace old or compromised bone so as to maintain structural integrity under normal loading conditions. These functions are carried out by bone-resorbing cells (osteoclasts) and bone-forming cells (osteoblasts) that may change the size, shape, and mass of the bone, particularly during growth, through the process of modeling. During modeling, bone resorption and formation occur independently of one another on different surfaces. As the skeleton matures, the process of remodeling predominates, in which osteoclasts and osteoblasts work in coordinated groups called bone remodeling units, to maintain bone mass and structure while replacing old bone.