Medical student receives award for finding out drugs to treat peripheral vascular disease

Working at a Saint Louis University laboratory, second-year medical student Weston Gordon performed several studies investigating two novel drug therapies that may be useful in the treatment of peripheral vascular disease in patients with Type 2 diabetes.

Gordon presented the findings of his research project at the 49th annual Alpha Omega Alpha Medical Student Research Forum at Saint Louis University and won first place.

He joined the lab of Randy Sprague, M.D., professor of pharmacological and physiological science at SLU last summer after taking his class in the first year.

"Weston did a lot of the heavy lifting for the project," Sprague said. "His experiments worked exceptionally well."

Gordon, a St. Louis native, contributed to the research study by applying a technique of delivering drugs to the red blood cells that could avoid the cardiac side effects.

Peripheral vascular disease, also known as peripheral arterial disease, is a common circulatory problem that compromises the appropriate amount of blood flow to the limbs.

"So far there have been limited drug therapy options for this condition," said Gordon. "One of the classes of drugs that are currently used to treat peripheral vascular disease can cause adverse cardiovascular side effects."

Gordon, who conducted the experiments in a lab setting, delivered the first drug, Cilostazol, using liposomes - tiny particles made from material similar to the cell membrane that interact extensively with red blood cells. These particles can be loaded with drugs for delivery to red blood cells from patients with diabetes. Once the drug reached the cells, Gordon saw signs of the drug's effectiveness.

Cilostazol is a drug that is used to treat intermittent claudication - pain in the legs that worsens when walking.

"We believe the side effects can be avoided if the drug is targeted to red blood cells using the liposomes," he said.

Gordon wanted to design a method that would directly target those cells with the drug.

"The reason we needed liposomes for Cilostazol delivery is because it is in a class of drugs that have been shown to cause adverse cardiac side effects," Gordon said. "Using liposomes allowed us to potentially avoid these side effects, so that this drug can be used to treat vascular disease in patients with Type 2 diabetes."

After seeing positive results from the first series of experiments, Gordon designed a second experiment with another drug but without using liposomes.

He used Zaprinast, a drug that works in a similar fashion to Viagra. Since this class of drugs does not have adverse cardiac side effects like Cilostazol, Gordon did not use liposomes but rather incubated the cells with the drugs directly.

"These drugs have never been tested to treat this disease in patients with Type 2 diabetes," he said. "Cilostazol is FDA-approved for treating these types of problems, but it is not an advisable treatment option for patients with certain types of heart disease. On the other hand, Zaprinast is not a drug used clinically, but our successful use of it is what makes us think that Cialis or Viagra would work in a similar fashion."

Unlike Cilostazol-loaded liposomes, which need to be delivered intravenously, Zaprinast and drugs that work similarly can be taken orally.

The next step would be to test the efficacy of these therapies on patients with diabetes-associated peripheral vascular disease.

Gordon feels fortunate to have collaborated on a high profile project with an accomplished researcher.

"These therapies can have immediate impact on how physicians treat vascular disease in patients with Type 2 diabetes," he said.

Gordon will present his work at the 55th Annual National Student Research Forum in Galveston, Texas, in April.

Source: Saint Louis University School of Medicine