Plastic Aspirin Gets Rave Reviews

0 Comments | Insight on the News, Oct 2, 2000 | by August Gribbin

Someday soon, people are likely to take `PolyAspirin,' a new drug that eliminates stomach bleeding and other side effects. The medication may help mend broken bones and heal hearts.

Kathryn Uhrich, a professor of chemistry at Rutgers University in New Brunswick, N.J., has found a way to recast the essential component of aspirin, salicyclic acid, as an elastic polymer compound. The new drug, PolyAspirin, consists of some 100 molecules strung together in a compound that doctors hope will eliminate stomach bleeding and ulcers among patients who take conventional aspirin to combat heart disease, reduce arthritic pain and fight inflammatory ailments. What's more, studies with mice show the polymer aspirin stimulates bone growth.

PolyAspirin isn't aspirin in a plastic coating but a "plastic-like" pill, created through "a process that's hard to explain without drawing pictures," concedes Uhrich. Regular aspirin breaks down and releases its active ingredient within 15 minutes of reaching the stomach. There it can affect sensitive stomach tissue. But in plastic form, the drug maintains its integrity until reaching the intestines, where it can be released into the bloodstream to reduce pain and inflammation with no known harmful effects.

Although researchers anticipate that clinical trials in humans won't begin for about two years, medical scientists already predict great things from the drug. "I'm enthusiastic about Uhrich's work because, basically, she has found a way to deliver this strong anti-inflammatory drug directly to the site of inflamed tissue," says Eleni Kousvelari, chief of biomaterials, biomimetics and tissue engineering at the National Institutes of Health. "It's a new drug-delivery system. And to me, it's promising for the future."

As a practical matter, the discovery means that aspirin users in the future should be able to take smaller PolyAspirin pills and use them less frequently because the drug's effect lasts for 20 hours. Also, "since aspirin is used to treat inflammation, this could be useful in virtually any condition whose name ends in -itis," says Uhrich.

Drug and medical-device makers are as interested in the process that led to the creation of the drug as to the drug itself. It's apparent the polymer aspirin can be used as a coating, and it can be manipulated so that it releases its active ingredient quickly or slowly as required.

"That's an advantage. Take the metal stents used in angioplasty," explains Uhrich, referring to the pencil-thin mesh tubes placed in arteries to improve blood flow to the heart and keep the passageway permanently open. "They can be coated with the aspirin so that when they're implanted in an inflamed artery, the active ingredient will slowly release and reduce the swelling." Similarly, the pins and joints used as implants for securing broken bones could be coated with polymer aspirin, and dentists see a use for the plastic drug in treating periodontal disease.

Indeed, there are so many practical applications for Uhrich's basic research that Rutgers has established a company called the Polymeric Co. to direct manufacturing, work with partners and handle the administrative chores involved in meeting Food and Drug Administration requirements. "My idea is for consumers to see this soon," says Uhrich. "But I'm a research scientist and running a company isn't my kind of work. Rutgers has named me chair of the scientific advisory board."

RELATED ARTICLE: Healthier Hearts

Physicians in Boston have injected a gene into the hearts of chronically ill heart-attack victims, provoking the growth of new blood vessels and dramatically improving their health.

In previous trials, the genes were encapsulated in a virus, explains Jeffrey M. Isner, professor of medicine and pathology at Tufts University School of Medicine and a pioneer in the use of gene therapy to treat heart disease. His team defied conventional wisdom and directly injected small, circular pieces of DNA called plasmids into the heart. The gene, called VEGF (for vascular endothelial growth factor), promotes blood-vessel development.

"There has been great concern about whether gene therapy works," says Isner. "This is very solid evidence that it does."

All the chronically ill patients in the trial had experienced at least one heart attack. All had undergone bypass surgery. And all but one had undergone balloon angioplasty one or more times to open clogged arteries.

--AG