Cell-based therapies for regenerating bone

Osteo-integration of bone grafts or bone substitutes is a very long process, which is suboptimal in the majority of clinical situations. We are continuing research into the mechanisms underlying the remodeling at the graft-host interface. Our earlier studies showed that supplementation of blood-derived product either as platelet rich plasma (PRP) or serum albumin can markedly improve bone remodeling. However, in order to create clinically feasible treatment protocols the biology of graft integration must be understood in greater detail and the mode of action of serum-supplemented bone grafts should be clarified. Under the present proposal we aim to investigate the allograft-stem cell composite under in vitro simulated ischemia and test its vascularization potential. Human bone explant will be harvested from femoral heads and exposed to oxygen-glucose deprivation in order to simulate ischemia. Cell viability will be monitored through fluorescent dyes and metabolic assays. Serum albumin and PRP coating will be investigated as potential growth-promoting factors after ischemia. In another line of experiment we shall implant bone chips in chicken egg the chorioallantoic membrane and monitor the vascularization potential. We expect that these experiments will allow a deeper understanding of bone graft remodeling and will lead to the design of better bone substitutes. This project is funded by the NFB (NÖ Forschungs- und Bildungsges.m.b.H.).