A Formula for Success
From energy storage to drug delivery, various fields may benefit from U of G chemist's work
BY ANDREW VOWLES
|Chemistry professor Dmitriy Soldatov studies arrays for holding gases and chemicals. Photo by Martin Schwalbe|
What do new vehicle fuels have to do with improved pharmaceuticals or the burgeoning field of nanoscience? Look at the underlying chemistry and you begin to see connections between seemingly disparate fields. They all fall under the research eye of Prof. Dmitriy Soldatov, a Russian-trained inorganic chemist who recently joined U of G`s Department of Chemistry.
Call it supramolecular chemistry, or understanding how molecules come together to make new entities like the ones studied by Soldatov. Among the building-block units he uses are dipeptides — chains of amino acids smaller than proteins. Bring together dipeptides and you make a porous crystalline framework whose micro-sized gaps can hold various compounds, similar to the way a sponge holds water in its pores.
The chemist's interests lie in two main areas: energy and drug delivery.
He's looking at ways to use these molecular arrays to hold gases and chemicals. Held in a matrix, hydrogen or methane might be separated and stored apart safely until needed — a key benefit for gases that normally mix with potentially deadly consequences.
Soldatov points to a naturally occurring example from both Canada and his native Siberia. Gas hydrates are ice-like substances whose water framework contains natural gas in its pores. Gas hydrates are a potential source of energy found in most parts of the world, including Northern Canada and Siberia, where he studied chemistry at Novosibirsk State University.
Dipeptides might also find use in biomedical applications as new forms of pharmaceuticals. Suppose a particular compound dissolves more readily when it's contained in a matrix, says Soldatov — or, conversely, becomes more stable. Perhaps consumers prefer to take a particular liquid drug in pill form, or maybe a particular substance needs to be kept dry until used.
Held in a dipeptide array, the substances take on new properties, almost as if they'd become new drugs, he says.
“The basic formulation remains the same, but placed in a matrix they may have a different solubility.”
Pharmacists might not be the only applied chemists interested in these products, he says, pointing to food scientists who might find ways to use them to capture and preserve flavouring in foods. Dipeptides also hold potential as sensors for detecting various substances in water or air, including dangerous gases or pollutants.
Elsewhere they may actually trap and store harmful materials, such as zeolites used to encapsulate radioactive waste after the Chernobyl nuclear accident in 1986.
Soldatov has experimented with combining metals and organic substances to mimic inorganic zeolites, a family of silicates whose major use lies in making vehicle fuels. He did some of that work at the National Research Council (NRC) in Ottawa, where he worked until joining Guelph this summer.
Along with chemist John Ripmeester at the NRC's Steacie Institute for Molecular Sciences, he studied the use of these metal-organic and peptide-based materials. The researchers were interested in their potential to become porous or non-porous, a property that might be useful in on-off sensing devices that switch from one state to the other. Or imagine a hospital having not bottles of oxygen on hand for patients but a simple device that could use these chemical principles to pull oxygen from the air.
In 2004, the Canadian and Russian collaborators discovered a new class of “biozeolites” that might find uses as catalysts, molecular storage houses or molecular sieves.
Soldatov, who has published more than 80 peer-reviewed articles and has edited the Journal of Structural Chemistry, stresses that he's working at the fundamental end rather than with direct applications. Before coming to Canada, he worked at the Institute of Inorganic Chemistry, part of the Russian Academy of Sciences, and at the Institute of Physical Chemistry in Poland.
He says the city of Guelph is similar in size to his home city in Russia. “Coming to Guelph is kind of coming back to where I started.”
Here, he's found a number of like-minded chemists in his department. He's also exploring links with various scientists on campus involved in nanoscience research and teaching, including planning for next year's launch of a nanoscience degree.
Soldatov plans to apply for funding to acquire an X-ray diffractometer, a key instrument for studying materials on that tiny scale.