Helping keen brittle bones from breaking
There are two categories of bone cells:
1) Osteoclasts: these cells resorb or dissolve the bone, and;
2) Cells of the osteoblast family, which consist of osteoblaststhat form the bone, osteocytesthat help maintain bone, and lining cellsthat cover the surface of the bone
Although new bone formation and repair of the damaged bone are common but they are not always guaranteed. Three most commonly encountered conditions that need filling of a given space with bone tissue are fracture non-union, benign bone defects and spine fusion surgeries. Of these, fractures are the most prevalent bone pathology. While most of these fractures heal with no complications whether treated conservatively or surgically, some 5–20% of all fractures can result in delayed union or non-union. A fracture is considered ‘non-union’ when no improvement is detected for consecutive 3 months or no union is achieved over 8–9 months. Introduction of mesenchymal stem cells (MSCs) can support bone healing and regeneration when an optimal environment is provided by means of mechanical stability and establishment of a systemic anabolic state.
Osteogenesis imperfect is a group of genetic disease of the bone where abnormality of the collagen type I gene product is responsible. Clinically, these conditions are manifested by malfunctioning of the connective tissue leading to increased susceptibility to fractures, fragile and deformed bones, slow growth and low bone mass. Currently fractures are treated as they occur and bisphosphonates are administered to increase bone mass. However, there are concerns of potential adverse effects of the long-term treatment with these drugs in children. Transfusion of ex vivo expanded MSCs can help to increase bone mass and improve bone morphology and architecture in these cases.