Georgetown College. Georgetown University.

By Theodora Danylevich

A crystal is made of millions of molecules. They can grow quite large, into the beautiful arrangements that we are most familiar with in precious and semiprecious stones, but they can also be microscopic in size. Table salt, computer chips, and fireworks are all composed of crystals. They also play a crucial role in pharmaceuticals, making it possible for medications to be produced in tablet form. Unfortunately, however, crystals can also be implicated in ailments such as gallstones, kidney stones, or gout.

The researchers in Dr. Jennifer Swift’s lab are breaking ground by approaching the study of crystals in a very focused way: “Our key purpose is to understand how they grow and form,” says Dr. Swift, an associate professor in Georgetown University’s Department of Chemistry. To this end, she and her researchers spend much of their time using different analytical methods to synthetically grow and analyze crystals in the lab.

“Key properties to consider when assessing a crystal are its stability, solubility, and shape,” explains Dr. Swift. “Pharmaceutical companies spend a lot of time and effort trying to formulate tablets in a way that maximizes their shelf life and solubility profile. If the active ingredients in a tablet don’t dissolve, the drug won’t be properly absorbed and do what it’s supposed to do. On the other hand, some crystalline solids can decompose after some period of time into other molecules that the Food and Drug Administration may not consider to be safe. These factors can determine whether a drug candidate may be developed into an actual product.”

Crystal shape can also be an important factor. For example, table salt crystals are most useful in cube form—if salt were needle-shaped, it would be very difficult to dispense out of a salt shaker. Most people don’t really think about the fact that salt could come in different shapes, but Dr. Swift and her students not only know this, but are also able to manipulate the shapes of crystals in their lab.

While synthetic crystals like those in pharmaceuticals are grown in a controlled environment; pathogenic crystals, such as those found in kidney stones or gallstones, are developed in a much more complicated environment, with a variety of unpredictable variables and numerous other molecules present.

“Stones are heterogeneous deposits of lots of different crystals, held together by a kind of glue,” says Dr. Swift. “No two stones are exactly alike, and some of the components are metastable, meaning that the crystals can transform from one molecular arrangement to another.”

Predicting what type of crystal will form in a perfect solution is challenging, and in complex biological systems it can be even more so.

“As chemists, we work in model systems to help us nail down some of the basics in solutions with as few variables as possible,” says Dr. Swift. “As we gain a better understanding of a particular crystal system, we gradually include additional variables so that our model more closely resembles that of complex physiological fluids.”

Dr. Swift’s research team is interested not only in the molecular arrangements of molecules within crystals but also in crystal surfaces. Properties such as adhesion and aggregation are directly related to the “stickiness” of individual crystal surfaces.

“Making such measurements is not something that is routinely done in a lot of labs,” Swift says, “but for some molecules, such as the ones that aggregate together to form gallstones and kidney stones, we know that this is a property worth investigating.”

Through this research, Dr. Swift and her students are elucidating some of the fundamental steps that occur in the pathogenic formation of crystals and stones in the gall bladder, the kidney, and in cases of gout.

“We hope that this may one day lead to preventive treatments, as well as help physicians to recommend different treatment approaches,” says Dr. Swift.

Outside of her intensive laboratory work, Dr. Swift also teaches Organic Chemistry to more than 200 students a year. Her commitment to teaching has been recognized both on the college and national level. She is a past recipient of the College Dean’s Award for Excellence in Teaching (2005) and was named a Camille-Dreyfus Teacher Scholar (2004). Since 2006, she has also co-directed with Dr. Sarah Stoll the Chemistry Department’s National Science Foundation Research Experiences for Undergraduates (REU) program, which brings several other undergraduates to campus for an intensive summer research experience. Her care for and attention to her students pays off.

“I think the projects in my lab provide excellent fundamental scientific training opportunities for students at all levels, both graduate and undergraduates,” says Dr. Swift. “All of the students who have graduated from my group are either gainfully employed or in medical or professional school. That to me is how I measure my success.”

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