The field of biomedical engineering is complex, to say the least. Out of all the sciences, it is one of the hardest to understand, as it centres around understanding and altering the millions of interactions occurring in our bodies everyday.
In a recent study published in Scientific Reports, McGill Alumni Hristo Valtchanov and his colleagues analyzed the intricacies of the human body, specifically blood flow, to determine if red blood cells (RBC) are negatively affected by intercellular collisions, where two or more cells come into direct contact with each other. Because of the density of our red blood cells and how small our blood vessels are in width, red blood cells frequently collide with each other when being pumped through our bodies.
Valtchanov believes that researchers have overlooked RBC collisions in the modeling of blood rheology—the science of blood flow—despite overall advances in said technology.
“In the biosciences, model representation is extremely important,” Valtchanov said in an interview with The Tribune. “It’s also important to challenge the assumptions people have on said models.”
He also argues that previous studies downplayed the importance of RBC collisions, suggesting they had a minimal impact on hemolysis—the destruction of RBCs. High levels of hemolysis is dangerous for the human body and can eventually lead to organ failure.
“It’s actually quite difficult to incorporate the effect of intercellular collisions, but no one had actually tried to quantify the effect, so we did a study doing just that,” Valtchanov said.
Thus, the researchers used viscoelastic simulations, measuring the RBC membranes’ responses to constant force or deformation to analyze how much strain intercellular collisions put on these membranes. They specifically analyzed this strain at different shear rates, which measure how fast layers of liquid move past one another.
“Basically, we made a simulation, and smashed the red blood cells together so that we could directly measure the effect of collisions on the strain experienced by the red blood cell membrane, and thus on hemolysis,” Valtchanov said. “We did this in simulation because the distribution of strain on the RBC membrane is exceedingly difficult to examine, particularly during a dynamic event like a collision.”
Their results showcased that overall, intercellular collision increased RBC membrane strain. In fact, they found that intercellular collisions were the main cause for membrane strain in RBC.
The importance of RBC collisions is made abundantly clear when considering what Valtchanov and colleagues had been examining beforehand.
“We began this study while we were trying to develop constitutive models for hemolysis. We use hemolysis modeling to try to predict the amount of damage to red blood cells when a medical device is implanted into a patient,” Vatlchanov explained.
These findings could help create new and improved biomedical devices, such as blood pumps, that are less likely to cause hemolysis, which could save lives as a result.
“A high degree of hemolysis is called ‘lethal hemolysis’ because it causes kidney failure and death. Lower doses have all sorts of other complications. It will slowly damage all of your other organs, and your kidneys will eventually give out.” Valtchanov said.
Ultimately, this study could help broaden current knowledge in modelling blood damage and creating biomedical devices.
“As engineers, our main challenge is to predict things,” Valtchanov added. “If you can predict something, you can control it, and design solutions to stop it from happening.”
Despite the progress that the researchers have made in this field, the work is far from over.
“The amount of knowledge you need to advance any science is a lot, to be frank,” Valtchanov said. “In general, there is so much work that needs to be done to improve our understanding of how the body works, to model the biomechanical processes that lead to diseases. The future of medicine is preventative, and harnesses data to take into account each individual person’s unique physiology.”
