Quick look
Iowa State's Aaron Rossini has developed solid-state nuclear magnetic resonance spectroscopy methods that are helping design better drugs, catalysts and semiconductors. He was just part of a national panel that explained how NMR tools are "a cornerstone of modern research."
AMES, Iowa - A tiny, solid sample of a drug, complete with active and inactive ingredients, spun at 50,000 revolutions per second while tilted at the "magic angle" of nearly 55 degrees relative to a high magnetic field.
A special instrument at the National Magnetic Resonance Facility at the University of Wisconsin-Madison produced all that spinning and angling so researchers could probe the nuclei of the sample's atoms. Some 270 miles away, the real-time results showed up as a blue line on the desktop computer of Aaron Rossini, a chemistry professor at Iowa State University and a faculty scientist at the U.S. Department of Energy's Ames National Laboratory.
That blue line showed several peaks of varying intensity and position. The position of these peaks offered clues about the structure of the solid drug, helping to locate the position of the hydrogen, oxygen and nitrogen atoms.
The solid-state nuclear magnetic resonance (NMR) spectroscopy methods developed by Rossini and his research group can help resolve "a persistent challenge in the pharmaceutical industry," according to a summary of one of Rossini's projects. That's "the successful design of the formulations for the administration of active pharmaceutical ingredients."
Rossini shared his NMR expertise during a panel discussion about "Pushing the Frontiers of Magnetic Imaging and Spectroscopy" at last week's annual meeting of the American Association for the Advancement of Science.
What is an NMR instrument?
Just down the hall from Rossini's basement office in Hach Hall is an instrument that looks sort of like a huge version of the propane tank under your household grill. Rossini's tank is elevated a few feet off the ground by three thick and sturdy legs. Cables run underneath. Piping and tubing extend from the top.
It's very, very cold inside - roughly -450 Fahrenheit, only a few degrees above absolute zero. An outer layer of liquid nitrogen and an inner layer of liquid helium provide the chill. In the middle is a superconducting magnet that conducts electricity without resistance and subjects samples to a strong magnetic field.
In Rossini's lab, the instrument's magnet is rated at 9.4 Tesla. It's a size, power and capability that's widely used in chemistry labs to study and determine atomic-level structures.
A few specialty labs around the country - such as the Madison lab and the National High Magnetic Field Laboratory (the "MagLab") in Tallahassee, Florida - have instruments with much more powerful magnets. The MagLab, for example, has an $18.7 million instrument rated at 35 Tesla. Researchers across the country, including Rossini, reserve time at the national labs for some of their experiments.
The 'magnetic moment'
Rossini, speaking in his Hach Hall office and regularly pausing to diagram molecules and their bonds on the back of an envelope, often mentioned the "magnetic moment" of atoms that NMR studies.
The NMR instrument's magnetic field aligns the nuclei. Radio pulses then knock the nuclei out of alignment - going from lower to higher energies - and the instrument records those differences.
The data come back as the peaks that Rossini, for example, was collecting from his Madison experiment.
A national talk about NMR methods
At his recent talk organized by Laura Greene, the chief scientist of the MagLab and a physics professor at Florida State University, Rossini spoke about "Unlocking the Periodic Table with NMR."
His message: "Solid-state nuclear magnetic resonance spectroscopy can be applied to determine the atomic-level structure of materials such as heterogeneous catalysts, next-generation semiconductors, and formulated solid pharmaceuticals."
Can any of that apply to your daily life?
Well, yes. NMR tools are "a cornerstone of modern research in drug design, sustainable energy materials, and quantum systems," according to a summary of the panel discussion.
Studying drug ingredients
Rossini is leading a new three-year, $492,000 study of the structures of active pharmaceutical ingredients and commercial drug products. The U.S. National Science Foundation is supporting the work.
The first part of the study is developing new methods that improve the sensitivity and resolution of NMR data. Graduate students and undergraduates will be part of the project, learning to prepare drug samples, perform NMR experiments and computationally model atomic structures.
As Rossini explains his work, he mentions a 2024 report by the National Academies of Sciences, Engineering and Medicine, "The Current Status and Future Direction of High-Magnetic-Field Science and Technology in the United States."
One major conclusion: "The United States needs to reestablish a level of support for state-of-the-art NMR research that will allow laboratories in the United States to regain a position of leadership in NMR-based research areas."
That means more instruments producing ultra-high magnetic fields which sharpen resolution and improve the data collected.
"NMR signals are very broad," Rossini said. "Some of our studies need these very high magnetic fields to improve resolution and sensitivity. With these capabilities, we will be able to study NMR signals from elements like oxygen and nitrogen that are difficult to study with lower field instruments. Ultimately, this will help chemists to design better materials and pharmaceutical companies to design improved drug formulations."
