Biomedical engineering professor leading new blood vessel breakthrough

A medical engineering breakthrough by a team of researchers at the Wayne State University College of Engineering may revolutionize the way we treat a wide variety of diseases. The research creates customized blood vessels that conform to the varying sizes and thicknesses of arteries in the human body, aided by the utilization of unique, 3-D printed inserts.

"We're really excited about this," says Mai T. Lam, assistant professor of biomedical engineering and a member of the university's Cardiovascular Research Institute. "Our most recent work presents a new, neat way to engineer blood vessels. We're hoping it can help a lot of patients in the future."

Until now, techniques for tissue engineering of human blood vessels took a one-size-fits-all approach - existing processes didn't allow for natural variations in vascular size or vessel wall thickness. After more than a year and a half in the laboratory, Lam and her team - Cameron Pinnock, Elizabeth Meier, Neeraj Joshi and Bin Wu, all from the WSU College of Engineering - developed an innovative method of producing customizable, self-organizing vascular constructs built upon a major structural component of normal blood vessels: the smooth muscle layer, or tunica media.

"Our vessels are completely made out of cells, so you should have far fewer issues with rejection when they are inserted into the body," Lam says.

"We take human cells that are actually derived from the aorta, cardiac cells, then we make a cell sheet out of them," she explains. "You can put them in a Petri dish and they'll form a sheet. We take that sheet and let it form a ring around a plastic post we have in the middle of the dish, then we take that ring and stack it on top of other rings we have made out of human cardiac cells until we form a tube in the form of a blood vessel. That's how we're getting the blood vessel structure."

In today's bioengineering field, most techniques for replicating blood vessels, even from some industry leaders who have clinical trials in progress, also involve a plastic scaffolding or tube upon which cells are stacked, but the tube is placed inside the patient along with the cells. "There are inherent restrictions from the plastic itself, because it can't really move as well as natural tissue, and it can't grow with the body, either," says Lam.

A prime factor in the College of Engineering team's development of engineered vessels is the evolution of 3-D printed inserts. "Absolutely," Lam says. "The 3-D printing technology is a very easy and rapid prototyping method for us."

Lam's team is now entering the next phase of the project. "The natural blood vessel has three layers to it, and we've only finished one layer so far: the media layer," Lam clarifies. "So now we're working on the other two layers so that we can get full function out of the blood vessels. I think our ultimate goal is to combine this with our work in the lab with stem cells. You can derive stem cells from fat tissues, so we obtain the leftover tissue from cosmetic surgeries. We're looking at isolating those stem cells and, after we finish the three-layer blood vessel construct, changing those cells into vascular cells so that we can make patient-specific blood vessels."

Meanwhile, the team is working on its game-changing process with Wayne State Technology Commercialization. "The technique is a little hard to learn without having some experience already, so we still have some decisions to make," Lam says. "It depends on which direction our lab wants to take."

Could the stacks of customizable blood vessels eventually be called Lam Vasculature? "I'm a little too shy for that," she replies, laughing. "We'll probably call it something else.