University of Oregon bioengineers and chemists combine ring-shaped molecules with a novel 3D printing process.
Researchers at the University of Oregon have mixed fluorescent ring-shaped molecules into a novel 3D printing process to create intricate, glowing structures which could support the development of new kinds of biomedical implants.
The advance addresses a common design challenge by making the structures easier to track and monitor inside the body, enabling researchers to distinguish implants from internal tissues.
“I think it was one of those strange times when we said, ‘Let’s try it,’ and it pretty much worked immediately,” said Paul Dalton, associate professor in the department of bioengineering at the University of Oregon in a press release.
Dalton’s lab specializes in intricate, novel forms of 3D printing. His team’s signature development is a technique called melt electrowriting, which allows relatively large objects to be 3D printed at very fine resolution. Using that technique, the team has printed mesh scaffolds that could be used for various kinds of biomedical implants.
Such implants could be used for applications as diverse as new wound-healing technology, artificial blood vessels or structures to help regenerate nerves. In a recent project, the lab collaborated with the cosmetics company L’Oreal, using the scaffolds to create a realistic multilayered artificial skin.
Dalton collaborated with Ramesh Jasti, a professor in the department of chemistry and biochemistry whose lab is known for its work on nanohoops: ring-shaped carbon-based molecules that have a variety of interesting properties and are adjustable based on their precise size and structure. The nanohoops fluoresce brightly when exposed to ultraviolet light, emitting different colors depending on their configuration.
Dalton and Jasti discussed the idea of incorporating the nanohoops into 3D printed scaffolds to make the structures glow.
“We thought it probably won’t work,” Jasti said, but he was pleased to be proven wrong.
According to Dalton, people have tried to make the scaffolds glow in the past, but with little success. Most fluorescent molecules break down under the lengthy exposure to heat required for his 3D printing technique. Fortunately, Jasti’s lab’s nanohoops are much more stable under high temperatures.
Though both groups might make their craft look easy, “making nanohoops is really hard, and melt electrowriting is really hard to do, so the fact that we were able to merge these two really complex and different fields into something that’s really simple is incredible,” said Harrison Reid, a graduate student in Jasti’s lab.
Just a small amount of fluorescent nanohoops mixed in to the 3D printing material mixture yields long-lasting glowing structures, the researchers found. Moreover, because the fluorescence is activated by UV light, the scaffolds still look clear under normal conditions.
While the initial concept worked very quickly, it’s taken several years of further testing to fully scope out the material and assess its potential. Dalton and his team ran a battery of tests to confirm that adding the nanohoops didn’t affect the strength or stability of the 3D printed material. They also confirmed that adding the fluorescent molecules didn’t make the resulting material toxic to cells, which is obviously important for biomedical applications.
The team envisions a range of possible applications for the glowing materials they’ve created. Dalton is particularly interested in the biomedical potential, but a customizable material that glows under UV light might also have use in security applications, Jasti said.
They’ve filed a patent application for the advance and eventually hope to commercialize it. And both Jasti and Dalton are grateful for the serendipity that brought them together.
“We get cool new directions by having people who don’t usually discuss their science come together,” Dalton said.
Their research is published in the journal Small.
