SDSU researches DDGS zein protein in cancer drug

By Ryan C. Christiansen | July 08, 2008
Web exclusive posted July 10, 2008 at 3:11 p.m. CST

The zein protein from distillers grains might someday help women in the fight against breast cancer, according to research being conducted at the South Dakota State University College of Pharmacy in Brookings, S.D.

Omathanu Perumal, assistant professor in pharmaceutical sciences at SDSU, said that while zein is predominantly used today as a moisture barrier coating in pharmaceutical tablets, candies, and paper products, it can be used in its nanoparticle form to deliver cancer drugs to cancer cells while bypassing healthy cells. He said initial tests using zein have produced "very promising" results in delivering the cancer-fighting drug Doxorubicin into breast cancer cells. According to the drug information provider Gold Standard, Doxorubicin is a chemotherapy drug used to treat a number of cancers, including bone, breast, stomach, lung, bladder, thyroid, ovarian, as well as leukemia, Wilms' tumor, and lymphoma.

"I was looking for a biopolymer which is biodegradable and safe to use in human applications and that is how I came across zein," Perumal said. "Nobody has looked at it from a drug delivery point of view and so I thought I might kind of explore those applications here."

Perumal said his first challenge was to break down the zein protein particles into their nanoparticle form, approximately 500 times smaller than the diameter of a human hair. He said that delivering chemotherapy drugs in nanoparticle-sized packets helps to kill cancer cells without killing healthy cells, because while nanoparticles are able to pass through the walls of blood vessels in tumor tissue, they are not able to pass through the walls of normal blood vessels.

Perumal said the second challenge was to prevent the human immune system from adversely reacting to having a protein injected into the bloodstream. However, he added that the second challenge was solved by the first, because the immune system does not react to the protein in its nanoparticle form.

One of the advantages of using zein is that it can prevent water absorption, Perumal said. "As far as drug delivery is concerned, when something is not water soluble, that means it is going to retain a sustained drug release for a longer period of time," he said. "In fact, we have shown that it can sustain a drug release for up to a week or so, maybe more than that."

Perumal said human clinical trials using the zein protein to deliver drugs might be possible in eight to 10 years.