Samantha Sullivan
samanthasullivan.md@gmail.com
Cal Poly engineering seems to have no bounds. Students learn to engineer cars, tractors and even planes. However, in the biomedical field, students are learning something relatively new, and rather mysterious: They’re learning how to engineer tissues.
Biomedical and general engineering associate professor Kristen O’Halloran Cardinal runs the tissue engineering research lab on campus. Undergraduate and graduate students alike grow coronary artery-sized blood vessels to test stents — small mesh tubes used to treat weak arteries, according to the National Heart, Lung and Blood Institute.
“Tissue engineering is such a new field, it’s sounds sexy and mysterious,” Cardinal said.
Cardinal said the purpose of her research lab is to test these stents before they are tested in animals. She hopes this will reduce the need for animal studies; however, until the model is “really sound,” Cardinal said the Food and Drug Administration (FDA) and other regulatory groups will want to see the animal data before approving the stents for humans.
What Cardinal and her students do in the lab is different from what her colleagues do, she said.
When someone has a heart attack, doctors can take a blood vessel from the person’s leg to replace the blocked one during bypass surgery. Or, scientists can take cells and grow a new blood vessel.
The problem with the latter, according to Cardinal, is a person wouldn’t know they could have a heart attack until they have one. Tissue engineering takes time, and if someone is undergoing a heart attack, they need something right away.
In the future, it would be nice to have blood vessel banks (much like today’s blood banks) so a replacement is always on hand, Cardinal said.
Another function of tissue engineering happens through the Cal Poly Cartilage Biomechanics Group run by adviser and mechanical engineering professor Stephen Klisch. The group’s focus is to create cartilage for people with damaged joints, graduate student Nathan Balcom said.
Other functions of tissue engineering include creating patches to fix small problems. For example, scientists can tissue-engineer a piece of a heart or bone but not the whole thing — yet.
“People are starting to work on that,” Cardinal said.
Graduate student and lab manager Rachel Gohres took Cardinal’s biomaterials class and found the material extremely interesting, she said.
“It was the first thing that got me excited about my major,” Gohres said.
Like most future prospects, Gohres shadowed students working in the lab before joining. She shadowed then-graduate-student Aubrey Smith, becoming her “minion.” Gohres watched Smith’s experiments and conducted image analysis, she said.
Each student in the lab has his or her own project to work on. Gohres’ project is a spin-off of Smith’s work, she said. Biomedical engineering sophomore and youngest lab student Scott Herting is poised to take over that project. However, he is looking at a different cell type.
Gohres’ project consists of looking into different extra cellular matrix proteins, otherwise known as proteins coatings. She is looking into implementing them into a tissue-engineered blood vessel mimic to enhance cell adhesion.
Gohres hopes coating the polymer can encourage the cells to attach more efficiently and approve viability — keeping more of the cells alive.
Herting is looking at the effects of different protein coating on the adhesiveness of smooth muscle cells to the blood vessel mimics in the lab.
In the lab, students try to grow blood vessel mimics in a bioreactor, which Herting said looks like Tupperware with tubes. Cells are pumped through a tube in the hope they will stick to the polymer scaffold and form like they would in a blood vessel.
Herting is looking at how the conditioning media used in the lab compare to more expensive media and whether it is worth the upgrade.
The lab work taught Herting that tissue engineering is actually something he likes and is interested in pursuing, he said.
“Tissue engineering blows my mind,” Herting said. “It’s fascinating and cool that I have a chance to be a part of it.”
When Gohres first started at the lab, she was doing experiments she had never done before. With experiments like that, they tend to fail, she said. Gohres thought she was wasting everyone’s time and money, and talked to Cardinal about her concerns. Cardinal told Gohres she should never think like that, and if she walked away from the experiment having learned something, then it was not a failure.
“I applied that to life as well,” Gohres said. “As long as you learn something, it’s not a failure. It’s success in another way.”
Cardinal hopes her students learn how to work with cells and tissues, as well as merge their engineering knowledge with the tissue medical knowledge. In the bigger picture, Cardinal hopes her students learn how to do research to answer questions no one knows yet.
“I hope my students come out and say, ‘Yeah, I know how to tissue engineer something,’” Cardinal said.
Typically, the lab contains approximately 10 to 15 students. However, because Cardinal was on maternity leave, the lab currently holds seven.
This is Cardinal’s first quarter back after having her daughter, Bridget, whom she called “her ultimate tissue engineering experiment.”
“Nature has it all figured out already,” Cardinal said, gesturing to the seven-month old baby sitting on her lap, “and we can’t even grow a blood vessel right.” (CE NOTE- The part about Bridget is the best part, move it to the top???)