Bledsoe J G, Slack S M
Department of Biomedical Engineering, The University of Memphis, TN 38152-6582, USA.
J Biomater Sci Polym Ed. 1998;9(12):1305-12. doi: 10.1163/156856298x00406.
Tissue factor (TF), a transmembrane glycoprotein expressed by numerous cell types, plays a critical role in the initiation of blood coagulation at sites of vascular injury. Activated products of the coagulation cascade may then enhance the inflammatory responses associated with wound healing. In the present investigation the ability of rat osteosarcoma (ROS) cells to express TF activity was examined following their growth on tissue-culture polystyrene (TCPS) and selected orthopedic biomaterials (titanium and zirconium alloys, and stainless steel). ROS cells exhibited significant TF activity as evidenced by the conversion of Factor X to Factor Xa in the presence of TF, Factor VIIa, and Ca2+. Factor Xa concentrations ranged from 1.0 fM per cell at 10 min to 6.0 fM per cell after 60 min. Additionally, ROS cells stimulated with calcium ionophore (A23187) exhibited approximately twice the activity of non-stimulated cells when grown on TCPS but not on the metallic substrates. ROS cells (stimulated or unstimulated) adherent to the zirconium alloy generated lower amounts of Factor Xa compared to those bound to the other alloys and unstimulated cells grown on TCPS. These results indicate that ROS cells cultured on these synthetic surfaces differentially express procoagulant activity and that cells grown on TCPS, but not the metallic alloys, exhibit increased TF activity in response to stimulation by calcium ionophore. This procoagulant activity may potentiate subsequent inflammatory responses associated with the use of orthopedic biomaterials and thereby influence the tissue compatibility of the implant.
组织因子（TF）是一种由多种细胞类型表达的跨膜糖蛋白，在血管损伤部位启动血液凝固过程中起关键作用。凝血级联反应的激活产物随后可能增强与伤口愈合相关的炎症反应。在本研究中，检测了大鼠骨肉瘤（ROS）细胞在组织培养聚苯乙烯（TCPS）和选定的骨科生物材料（钛合金、锆合金和不锈钢）上生长后表达TF活性的能力。ROS细胞表现出显著的TF活性，在TF、因子VIIa和Ca2+存在的情况下，因子X转化为因子Xa即可证明这一点。因子Xa的浓度范围从10分钟时的每细胞1.0飞摩尔到60分钟后的每细胞6.0飞摩尔。此外，在用钙离子载体（A23187）刺激时，ROS细胞在TCPS上生长时的活性约为未刺激细胞的两倍，但在金属基质上生长时则不然。与附着在其他合金上的细胞以及在TCPS上生长的未刺激细胞相比，附着在锆合金上的ROS细胞（无论是否受到刺激）产生的因子Xa量较低。这些结果表明，在这些合成表面上培养的ROS细胞差异表达促凝活性，并且在TCPS上生长的细胞（而非金属合金上生长的细胞）在受到钙离子载体刺激时表现出增强的TF活性。这种促凝活性可能会增强与骨科生物材料使用相关的后续炎症反应，从而影响植入物的组织相容性。
