February 9, 2021

photo of manuel rauschManuel Rausch, an assistant professor in the Department of Aerospace Engineering and Engineering Mechanics and the Department of Biomedical Engineering, was selected to receive a National Science Foundation (NSF) Faculty Early Career Development Program (CAREER) award for 2021.

Rausch was awarded for his proposal “Toward a Fundamental Understanding of Why Thrombus Dissolves, Persists, or Breaks Off.” Over the next five years he will use the award to develop experimental and computational strategies that will provide a better understanding of the biophysical properties of blood clots.

When a thrombus, or blood clot, forms in a vein or artery it can take one of several paths: it can eventually dissolve, causing no health issues; it might sit there for a while, or persist; or in the worst-case scenario, it can embolize, or break off, then travel within the blood stream and become “stuck” in an artery. If the clot blocks a main artery, it could lead to a number of serious medical conditions including stroke, heart attack or pulmonary embolism, making it one of the most common causes of death.

Although there are a number of known factors associated with patients who are more likely to develop blood clots, Rausch said why and when a clot takes one path over another is not currently understood in the medical community. He aims to offer some answers to these questions with this new research.

Rausch and his graduate students will conduct the research in the Soft Tissue Biomechanics Lab, where they will study the biophysical properties of blood to gain a better understanding of why a blood clot takes one path over another. The team will then develop computational models based on the results from the physical experiments.

For the physical experiments, they will perform a number of fracture and strength tests on samples of animal blood. Since the blood will arrive uncoagulated, they will first need to change it back into the form of a clot. Because blood clots are 90% water, their consistency makes it difficult to work with, so the researchers will cast and mold the clots into a more manageable shape for testing before beginning the experiments.

“The consistency of a blood clot is like half-digested jello, so it can be hard to work with,” Rausch said. “But the nice thing is, we can cast it into any shape for testing. We could make it into a gummy bear shape, for example.”

Once the clot has been casted and molded, Rausch will test the blood’s physical properties such as stiffness, fracture toughness and permeability using mechanical equipment in the lab.

Testing for stiffness, which Rausch said is the most fundamental property, will assess how the clot reacts when being pulled. Fracture toughness will measure how it resists being torn apart, which correlates with the likelihood of the clot breaking off. And permeability tells researchers how easily a thrombus can be penetrated by a fluid. If the permeability is high, for example, the blood-borne factors that help dissolve blood clots can make their way into the clots more easily, helping them to dissolve.

Using the results from the physical experiments, Rausch will then develop two types of computational models – a microstructural model and a predictive, continuum model – to help understand and predict the fate of a blood clot.

“The computational models developed from this research will provide the framework to aid in the optimization of treatment and therapeutic technologies for patients suffering from blot-clot related diseases,” Rausch said.

Rausch’s team is also conducting research using the blood of COVID-19 patients to see if they have an elevated risk for developing blood clots that embolize. To do this, they will compare the blood of coronavirus patients with that of healthy people to see whether it is more likely to break apart under pressure.

The NSF CAREER award is among the most prestigious offered to junior faculty, providing up to five years of funding to those who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of their organizations' missions.