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Archive - Oct 27, 2009

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New Medical Adhesive May Come from Sandcastle Worm

Scientists questing after a long-sought new medical adhesive describe copying the natural glue secreted by a tiny sea creature called the sandcastle worm in the latest episode in the American Chemical Society's (ACS) award-winning podcast series, "Global Challenges/Chemistry Solutions." Such an adhesive is needed to repair bones shattered in battlefield injuries, car crashes, and other accidents. The traditional method of repairing shattered bones involves use of mechanical fasteners like pins and metal screws to support the bone during healing. But achieving and maintaining alignment of small bone fragments using screws and wires is challenging, according to researchers who presented their study results at the ACS 238th National Meeting in Washington, D.C. in mid-August. The podcast is available without charge at iTunes and from the ACS at www.acs.org/globalchallenges. It features audio clips of Dr. Russell Stewart, a bioengineer at the University of Utah in Salt Lake City. Dr. Stewart says this synthetic glue is based on complex coacervates, an ideal, but so far unused, method for making injectable adhesives. Coacervates are tiny spherical droplets of assorted organic molecules (specifically, lipid molecules) that are held together by hydrophobic forces from a surrounding liquid. He explains that the idea of using natural adhesives in medicine is an old one dating back to the first investigations of mussel adhesives in the 1980s. Yet almost 30 years later, there are no adhesives based on natural adhesives used in the clinic.

Tel Aviv Researchers Search for “Prozac Gene”

In an effort to develop “best-fit, personalized regimen(s)” for treating depression, researchers at Tel Aviv University in Israel are undertaking a research program designed to identify genes that are associated with extreme responses to particular antidepressants such as Prozac. "Many drugs for treating depression are on the market," said Dr. David Gurwitz, leader of the new program. "The most popular ones, including Prozac, are the selective serotonin reuptake inhibitors (SSRIs). But they only work for about 60% of people with depression. A drug from other families of antidepressants could be effective for the other 40%," he said. "We are working to move the treatment of depression from a trial-and-error approach to a best-fit, personalized regimen. We've designed an experiment to search for elements that can determine who will, and who won't, benefit from drugs such as Prozac." The researchers will explore whole-genome gene expression profiles in cell lines from healthy people. Because Prozac and similar antidepressants are known to inhibit the growth of blood cells, the researchers are now screening a large collection of cell lines to determine which have the strongest and weakest growth-inhibition responses to SSRIs like Prozac. Those cells that exhibit extreme responses will then be screened across the entire human genome, to find out which genetic make-up works best with SSRIs. "Psychiatric pharmacology remains a black box," said Dr. Gurwitz. "Nobody knows why some people respond to Prozac-type SSRI anti-depressants, while others are helped by other kinds of antidepressants. The World Health Organization predicts by the year 2020, costs and lost productivity from depression will exceed those of cardiovascular disease as the leading cause of health expenditure in developed countries.