Fibrinogen Affects Blood and Bone Marrow Cell Functions on Titanium in vitro

Host derived blood protein adsorption is much more rapid than the migration of cells to foreign surfaces, so the effect of host proteins in blood on blood cells and bone marrow cells was investigated by means ofin vitroculturing of blood and bone marrow cells on titanium. A material preincubated with plasma induced high nonspecific esterase (NSE) activity and polymor-phonuclear neutrophil (PMN) elastase activity, but neither a serum- nor albumincoated material had the same effect as the plasmacoated material. Therefore, attention was paid to fibrinogen. On titanium coated with fibrinogen increases in not only NSE activity and PMN elastase activity in blood and bone marrow, but also tartrate-resistant acid phosphatase (TRACP) activity were observed in bone marrow cultures. A decrease in alkaline phosphatase (ALP) activity was also observed in the cultures. These changes of bone marrow cultures were reversed by the addition of recombinant human bone morphogenetic protein-2 to the cultures. These results suggested that bleeding around titanium affects the function of macrophages or neutrophils due to the effect of fibrinogen. Furthermore, it was suggested that this factor may affect the functions of osteoblasts and osteoclasts around a titanium implant with the inevitable side effects of implantation in bone tissue: bleeding and clotting.