Photo by Rob Felt
Study authors Yongzhi Qiu (left) and Wilbur Lam
Researchers have engineered a miniature model system for studying hemostasis.
They believe the device could serve as a drug discovery platform and potential diagnostic tool.
The team has already used the device to assess the effects of an antiplatelet agent and analyze blood from hemophilia A patients.
The researchers described this work in Nature Communications.
The team noted that hemostasis encompasses the interactions of platelets, coagulation factors, blood cells, endothelium, and hemodynamic forces.
“Current methods to study blood clotting require isolation of each of these components, which prevents us from seeing the big picture of what’s going with the patient’s blood clotting system,” said study author Wilbur Lam, MD, PhD, of Georgia Institute of Technology and Emory University in Atlanta, Georgia.
With this in mind, Dr Lam and his colleagues developed their device.
They believe it is the first system to reproduce all aspects of blood vessel injury seen in the microvasculature—blood loss due to trauma, clot formation by whole blood, and repair of the blood vessel lining. However, it does not reproduce aspects of larger blood vessels.
The researchers’ device has 3 layers. The top “vascular” layer consists of human endothelial cells cultured in a microchannel. The middle valve layer consists of a polydimethylsiloxane membrane, and the bottom is a “valve actuator” layer.
To assess hemostatic response, the researchers create a “wound” in this system. They exert both positive and negative pressure to create an opening about 130 micrometers across. Donated human blood can flow through this opening for testing.
The researchers said they used this system to demonstrate the importance of von Willebrand factor and endothelial phosphatidylserine in hemostasis.
The team used the device to test the antiplatelet agent eptifibatide as well. They found the drug leads to decreased clot contraction and a lower density of platelets within the hemostatic plug.
Finally, the researchers analyzed blood from hemophilia A patients and found that it “confers unstable hemostatic plug formation and altered fibrin architecture.”