Despite modern surgical trauma care, bleeding contributes to one-third of trauma-related death. A significant improvement was obtained through the introduction of tranexamic acid (TXA), which today is widely used in emergency and elective orthopedic surgery to control bleeding. However, concerns remain regarding potential adverse effects on bone turnover and regeneration. Therefore, we employed standardized cell culture systems including primary osteoblasts, osteoclasts, and macrophages to evaluate potential effects of TXA on murine bone cells. While osteoblasts derived from calvarial digestion were not affected, TXA increased cell proliferation and matrix mineralization in bone marrow-derived osteoblasts. Short-term TXA treatment (6 h) failed to alter the expression of osteoblast markers; however, long-term TXA stimulation (10 days) was associated with the increased expression of genes involved in osteoblast differentiation and extracellular matrix synthesis. Similarly, whereas short-term TXA treatment did not affect gene expression in terminally differentiated osteoclasts, long-term TXA stimulation resulted in the potent inhibition of osteoclastogenesis. Finally, in bone marrow-derived macrophages activated with LPS, simultaneous TXA treatment led to a reduced expression of inflammatory cytokines and chemokines. Collectively, our study demonstrates a differential action of TXA on bone cells including osteoanabolic, anti-resorptive, and anti-inflammatory effects in vitro which suggests novel treatment applications.
Keywords: bone regeneration; macrophages; osteoblast; osteoclast; tranexamic acid.