BONE GRAFTS FOR RECONSTRUCTION OF BONE DEFECTS (REVIEW).

Reconstruction of large size defects of bone is a challenging task. To this date, discussions and controversies on selection of auto-, allo-, xeno- or synthetic grafts continue to take place. Vascularized autologous bone graft is considered as gold standard in reconstruction of large size defects of bone; however an additional surgery is required for obtaining it. Allografts and xenografts possess osteoconductive features, but osteogenesis is less expressed and risk of various infection transmissions is high and may have probability of developing immunological conflict. Main advantages of grafts created from synthetic materials through bioengineering methods are biocompatibility and good bioreabsorption. Despite these features, studies related to the creation of an ideal bone graft continue to take place that should have biomechanical stability, be able to degrade within an appropriate period, exhibit osteoconductive, osteogenic and osteoinductive properties. Nowadays, there is an attempt of creating grafts that contain platelet-rich plasma, growth factors or stem cells for strengthening osteoconduction and osteoinduction of bone grafts. In 2016, we created bioactive bone from decellularized bovine femoral bone and freeze-dried bone marrow stem cell paracrine factors. We hypothesized that freeze-dried BMSC paracrine factors would have ability to strengthen osteoinduction, osteoconduction and osteointegration. Experimental and preliminary clinical investigations indicated that bioactive bone grafts containing freeze-dried BMSC paracrine factors may be used for reconstruction of large size bone defects. Despite acquired positive results, it requires multiple experimental and clinical studies for further improvement of graft.