Osteoblasts (OB)

Osteoblast are cells with single nuclei that synthesize bone.Osteoblasts are the major cellular component of bone. The functional part of bone, the bone matrix, is entirely extracellular. However, in the process of bone formation, osteoblasts function in groups of connected cells. Individual cells cannot make bone, and the group of organized osteoblasts together with the bone made by a unit of cells is usually called the osteon.Osteoblasts are specialized, terminally differentiated products of mesenchymal stem cells.Studies show that leukemia inhibitory factor can bind to the osteoblast cell surface and induce bone formation both in vitro and in vivo.They synthesize very dense, crosslinked collagen, and several additional specialized proteins in much smaller quantities, including osteocalcin and osteopontin, which compose the organic matrix of bone.The balance between osteoblast recruitment, proliferation, differentiation and apoptosis in sutures between cranial bones is essential for calvarial bone formation.