Scientists develop ‘vein-on-a-chip’ to study blood clots

A new device that mimics a human vein could replace the need for animals in medical studies that look into cardiac diseases. 

The vein-on-a-chip model has been developed by scientists at the University of Birmingham. It looks like a tiny channel, and incorporates valves that ensure the correct direction of blood flow.

The device is more advanced than previous models because the valves can open and close, mimicking the mechanism seen in a real vein. It also contains a single layer of cells, called endothelial cells, covering the inside of the vessel.

These two advances allow the device to be biologically reflective of a real vein, and it also replicates blood flow in a life-like manner.

“Organ-on-a-chip devices, such as ours, are not only created to help researchers move away from the need for animal models, but they also advance our understanding of biology as they are more closely representative of how the human body works,” said Dr Alexander Brill, one of the leaders of the research. 

The research team was able to use the device to demonstrate one of the basic mechanisms underlying venous clot formation using their newly developed model. Namely, the role of a bridge between a molecule called von Willebrand Factor and a surface receptor on platelets called glycoprotein Ib-alpha.

“The principles of the 3Rs – to replace, reduce and refine the use of animals in research – are embedded in national and international legislation and regulations on the use of animals in scientific procedures," Brill. "But there is always more that can be done. Innovations such as the new device created for use in thrombosis research are a step in the right direction.”

Deep vein thrombosis is the development of blood clots in veins, usually in the legs. It is a serious condition because the clot can detach and travel to the lungs, where it may block blood vessels, causing difficulty in breathing that may be fatal.

Deep vein thrombosis is the third most common cardiovascular disease after myocardial infarction and stroke, with tens of thousands of people in the UK developing this condition every year. With this new artificial vein, the Birmingham researchers hope to drive forward further investigations into this condition.

The researchers' findings have been described in a recent paper published in Frontiers in Cardiovascular Medicine.