Be Brief: Stent

close-up of a young woman holding a crocheted heart
close-up of a young woman holding a crocheted heart
Biodegradable zinc-based stents are both mechanically strong and biocompatible, making them good candidates for treating coronary heart problems.

Happy Valentine's Day. We're celebrating hearts with biodegradable stents that can help save lives now—but dissolve away when they're no longer needed and the body's natural healing process takes over.

The challenge is the same process that heals also covers up and prevents a biodegradable stent from fully disappearing. That's why Jeremy Goldman, a professor of biomedical engineering, is looking into different options.

Stents are designed to act like a culvert for weakened or damaged arteries. The most common expandable tubes made today are formed out of noncorrosive metals like stainless steel, but if they stick around too long then complications related to chronic inflammation set in long after stent deployment. Bioabsorbable polymers like poly L-lactic acid (PLLA) are one alternative, being both more flexible and better understood, but they lack the mechanical strength of metals. Iron and magnesium alloys have been the focus of biodegradable metal stents for the past two decades, but they also have problems, namely premature degradation (for magnesium) and oxide corrosion products that are poorly metabolized (for iron). 

Zinc and its alloys are the most promising candidates for stents designed to last one to two years. Goldman's lab has looked at the corrosion rates, inflammatory response, biocompatibility, surface interactions, and mechanical properties of zinc-based biodegradable stents. One of their studies—a long-term, 20-month survey in rats—shows the metal steadily corrodes and not too quickly. Another study focused on cell-zinc interactions and demonstrates the need for ongoing research to understand how zinc stents might work in a human body. The next step: Design the smartest stent with the best alloy.

 Be Brief Series

Some people think the sciences and arts can't mix. They haven't seen our staff photographer Sarah Bird's work. A research photo is worth a whole essay.

We writers like to tease Sarah. Sometimes in response to our long email explanations, she sends back: "Too many words." So in her honor, we started a blog series dedicated to the impact of research imagery. Enjoy.

 Grants and Funding

NIH National Heart, Lung, and Blood Institute 1R15HL129199-01

NIH National Institute of Biomedical Imaging and Bioengineering 5R21 EB 019118-02

Michigan Initiative for Innovation and Entrepreneurship, Technology Commercialization Fund, Grant #3093231

Original research conducted with research collaborators Jaroslaw Drelich, professor of materials science and engineering, and PhD graduate student Pat Bowen. 

Michigan Technological University is a public research university founded in 1885 in Houghton, Michigan, and is home to more than 7,000 students from 55 countries around the world. Consistently ranked among the best universities in the country for return on investment, Michigan’s flagship technological university offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, computing, forestry, business and economics, health professions, humanities, mathematics, social sciences, and the arts. The rural campus is situated just miles from Lake Superior in Michigan's Upper Peninsula, offering year-round opportunities for outdoor adventure.