Figure 1.

Blood clotting activation on TF-expressing surfaces in a vessel (in vivo) and in a reaction-diffusion experimental model (in vitro). Under normal conditions, TF is expressed by subendothelial cells only. In many pathological conditions, such as inflammation and cancer, TF can also appear on the surface of blood cells and endothelial cells, either isolated or in monolayers. TF density varies over a wide range. By analogy, coagulation in the in vitro model system used herein was activated by films with either uniformly distributed TF or TF-bearing cells. In both cases, the average surface TF density varied over two orders of magnitude. Spatial clot growth was recorded by means of light scattering. Initiation times, clot growth rates, and clot sizes after 40 min were determined as shown.