A pivotal moment in Polina Anikeeva’s career was when she looked at an MRI scan of Parkinson’s disease patient, about a decade ago.
Now professor of materials science and engineering and brain and cognitive sciences at MIT, Anikeeva had recently worked on optoelectronics, devices that can detect and control light, and her work was used to illuminate the quantum-dot displays on Samsung TVs. But Anikeeva’s research interests started to stray into biology and neuroscience, disciplines outside her immediate orbit.
“I wanted to apply my knowledge as a materials scientist and engineer to problems that were unsolved, to devices that didn’t exist,” said Anikeeva on April 22, while delivering the Department of Materials Science and Engineering’s twice-yearly Wulff Lecture.
She found those problems in nervous system disorders such as Parkinson’s. In Parkinson’s disease, neurons that produce the neurotransmitter dopamine in the brain begin to die off. Patients often have difficulty controlling or initiating movement, and symptoms get worse over time. Drugs help, but stop working after several years.
Deep brain stimulation (DBS) therapy is often the last resort. It has promising results; patients who undergo DBS often can better control their movement. But the procedure, involving placing electrodes into the brain, can have profound side effects, including a change in personality. There are two problems: the first is size. Electrodes are a thousand times larger than the brain cells they’re trying to stimulate. Complexity is an even bigger problem, Anikeeva said: different cells have different functions. “And if you're stimulating all of them at once, you don't know what's going to happen.”
Anikeeva and her research team draw from disciplines as diverse as materials science, neuroscience, and telecommunications to improve treatment for nervous system disorders. In pursuit of that goal, they’ve developed neural probes that match the brain’s physiology, so they can stimulate brain cells without causing damage to delicate tissues.
At last month’s public event, targeted toward first-year students, Anikeeva was introduced by DMSE department head Jeff Grossman, who gave a brief introduction to materials sciences and engineering. “We build matter from the atom up,” he said. The goal is to build materials with better properties and performance. “And we think about how to do that from a really broad range of other disciplines and ways of thinking.”
The Wulff Lecture series, created in 1977, honors John Wulff, a longtime MIT materials science professor who spearheaded the popular course 3.091 (Introduction to Solid State Chemistry). The idea of the series is to “inspire anyone who’s interested in understanding what our discipline does, what our discipline is about, why it’s exciting and impactful,” Grossman said.
Throughout her lecture, Anikeeva credited any impact her work could have on society on the interdisciplinary nature of materials science — the willingness to look to other fields for answers to hard-to-crack problems.
For example, figuring out how to trigger the right neuron would come from microbiology. Anikeeva turned to the work of a Stanford University bioengineering team that applied proteins from a microorganism called Chlamydomonas reinhardtii, a single-cell algae that uses light to propel hairlike appendages called flagella and swim. That same, light-driven mechanism can be used to stimulate a particular neuron. It’s a neuroscience research method known as optogenetics.
“We can now manipulate neurons that we want by using light and leave the rest — bystander neurons — alone, avoiding side effects,” Anikeeva said.
The problem of size would require a different type of thinking. For a material that could snake through the squishy softness of an organ like the brain — Anikeeva brought a food-grade brain from the butcher to display — she turned to telecommunications. Fiber-optic cables like those used to make long-distance calls were engineered to deliver electrical, optical, and chemical signals to the brain. But the material that makes up such fibers is stiff and could damage brain tissue.
Room for Jell-O?
As it turns out, the hydrogels that give the dessert its jiggly texture are similar to the elastic properties of the brain.
“Those are polymers that can absorb significant quantities of water and swell and assume the mechanics of the brain quite precisely,” Anikeeva said. Researchers can tune the material to mimic “every type of neural tissue.”
But to push a fiber with the property of a “wet noodle” into the brain requires yet another disciplinary detour — this time into the art world. Think of a paint brush, Anikeeva said. Its soft bristles couldn’t puncture anything, never mind a mass like a brain.
When dipped into paint and allowed to dry, though, its bristles harden and can serve as a wedge to penetrate soft tissue. This is exactly the way Anikeeva’s hydrogel-fiber device works in lab experiments on mice. On entering the brain, “it re-hydrates, and now assumes the mechanics of the brain and can move stealthily together with the brain, producing no damage.”
Another piece of Anikeeva’s research examines the way cells respond to thermal stimulation, which could lead to new kinds of therapeutic treatments. First, minuscule nanoparticles are injected into the body; then they’re heated up with a magnetic field. That opens up channels in nearby neurons, activating them.
Figuring out how to do that, again, required working across several fields. For example, using heat to stimulate neuronal activity comes from knowledge and application of cellular biology — “You drink hot tea, your tongue burns. You go out for Thai food, your tongue burns,” Anikeeva said, because the protein that responds to heat also responds to the spice in hot peppers. To ensure that nanoparticles can dissipate heat efficiently, Anikeeva’s team relies on materials chemistry and knowledge of crystal structure — the ordered arrangement of atoms in their makeup — to engineer their magnetic responses.
Combining it all
The mix of disciplines on view was what brought Catherine Song to the event. She went to Princeton University as an undergraduate and moved to the Boston area to work at Massachusetts General Hospital in a neurology lab.
“In undergrad I did a lot of organic chemistry — that’s cool, but I felt a lot of the movement in that is toward drug development and looking at specific enzymes and metabolic pathways,” says Song, who is thinking about doing graduate work in interdisciplinary research. “I really like the granular aspect of research and chemistry and materials, but how to combine all that is really exciting.”
First-year undergraduate students Mishael Quraishi and Karen Lei were also drawn to the lecture’s multifaceted topic. Quraishi, a newly declared materials science major, heard in the talk proof that she’s in the right area of study.
“I’m interested in not only materials problems but also how they can be applied to greater social issues, so health-care spheres — entrepreneurship is also something I’m interested in,” Quraishi says. “All of these interdisciplinary things I feel like DMSE allows me to explore multiple of those passions.”
Lei, who along with Quraishi also attended the Wulff Lecture in October featuring Department of Biological Engineering head Angela Belcher, noted the recent trend of connecting disciplines specifically with biology.
“If you looked at the 1900s, biology was very much more pure science — molecular biology looking into DNA structure, RNA,” says Lei, who’s majoring in physics. “Now, more and more people are looking at biology as a new kind of frontier where you integrate it with engineering, you integrate it with materials science, integrate it with electronic engineering as well.”
Adds Quraishi: “It also tends to be more about innovation and design rather than discovery. Once you discover the finished DNA, how can you iterate upon it?”