Simulating the formation of blood clots

Christian Spieker, Gábor Závodszky and Alfons Hoekstra have published a new paper in Physics of Fluids, highlighted as a special article and published in conjunction with a Scilight article.

During a bleeding injury, the body defends itself by initiating the process of blood clotting called hemostasis. However, in the case of thrombosis, this clotting process is mistakenly activated without any external injury. The improperly activated clot is called a thrombus and narrows the diameter of the blood vessel or blocks it completely, which can lead to a heart attack or stroke.

Blood thinners can reduce patients’ risk of thrombosis but are associated with significant side effects. Spieker et al. simulated the initial hemostasis environment to understand how the state of the blood vessel affects the early stages of platelet aggregation.

“The main motivation of this work is very basic,” said author Christian Spieker. “We want to improve our understanding of exactly how hemostasis differs from thrombosis to advance the development of antithrombotic agents.”

Their simulation mimics the flow of a vessel pierced by a micro-needle, an injury the size of a mosquito bite. They modeled both a cylindrical vessel and the space around the wound opening. Additional microfluidic experiments were performed using multiple pumps to control blood flow and pressure.

“The experiments in our study show that the initial step of this process (platelet aggregation) depends on the local flow environment,” Spieker said. “We concluded that certain flow conditions allow the formation of platelet aggregates, while cell divisions can determine their location and thus are highly relevant.”

With more information about thrombus formation, it will be easier to diagnose conditions at increased risk of thrombosis. They also hope that their work will lead to blood thinners that work based on specific flow conditions.