Bone morphogenetic proteins in fracture repair

Bone fractures represent a significant medical morbidity among aged population with osteoporosis. Bone morphogenetic proteins (BMPs) are suggested to have therapeutic potential to enhance fracture healing in such patients. Though BMP-mediated fracture healing has been well-documented in preclinical models, there has been no clinical study that demonstrated unequivocally that indeed a BMP when presented with an appropriate scaffold could provide basis for robust outcome for delayed or non-union diaphyseal bone fractures. This review presents a comprehensive insight towards the existing knowledge on the role of BMP signaling in bone formation and maintenance. Also therapeutic options based on BMP biology are discussed. A novel osteoinductive autologous bone graft substitute (ABGS) aimed to accelerate bone regeneration was developed and is currently being tested in the clinical setting. It comprises of a biologically compatible autologous carrier made from the patient's peripheral blood (autologous blood coagulum, ABC) and of rhBMP6 as an active ingredient. Such formulation circumvents the use of animal-derived materials, significantly limits inflammatory processes common in commercial bone devices and renders the carrier flexible, malleable, and injectable ensuring the ease of use. The ongoing clinical trials result will provide more detailed insights into the safety, tolerability, pharmacokinetics, and bone healing effects in humans and potentially provide novel and safe therapeutic options for bone repair.