Issue Date: September 20, 2010
Research efforts to purify drinking water contaminated with arsenic, identify carotenoids that can help prevent age-related macular degeneration, and elucidate the role of lung surfactants in respiratory distress syndrome were honored during a presidential event at the American Chemical Society national meeting in Boston last month.
Arup K. SenGupta, Frederick Khachik, and Ka Yee C. Lee are the 2009 recipients of the Astellas USA Foundation Awards, which recognize individuals or teams that have significantly contributed to scientific research that improved public health through their contributions in the chemical and related sciences. Each investigator received a $30,000 research grant from the Astellas USA Foundation’s Astellas Awards program, which is administered by the ACS Office of Research Grants.
During the symposium, SenGupta, a professor and past-chair of the department of civil and environmental engineering at Lehigh University, described his search for a sustainable solution to the arsenic crisis in developing countries. Despite heavy rainfall, countries such as India, Bangladesh, Laos, Vietnam, and Cambodia lack safe drinking water because poor sanitation practices make surface water undrinkable, SenGupta noted. Water drawn from underground sources contains trace amounts of arsenic, caused by soil leaching.
Symptoms of arsenic poisoning include severe skin lesions and cancer. “This is a crisis,” SenGupta said. “But at the same time, this is also an opportunity.”
In the 1990s, SenGupta invented the first polymer-based reusable arsenic-selective adsorbent that removes arsenic from water. The filtration systems use a hybrid anion exchanger that disperses iron nanoparticles throughout a polymer-based bead; the nanoparticles selectively adsorb arsenic and other contaminants from groundwater used for drinking. The systems have succeeded in reducing arsenic levels in drinking water from 100–500 ppb to well below the 50-ppb limit set by the Indian government, SenGupta noted.
SenGupta and his colleagues have since installed more than 200 arsenic-removal systems in the remote villages of eastern India near Bangladesh and Cambodia.
Another pressing issue that was addressed by one of the awardees is age-related macular degeneration (AMD). This condition is the leading cause of blindness and vision loss in adults who are age 60 and older. Studies have shown that the consumption of carotenoid-rich fruits and vegetables can protect against AMD and other chronic diseases.
Many people are familiar with the beneficial effects of α- and β-carotene, which, in part, are converted by the human body to vitamin A. But Khachik, a senior research scientist in the College of Chemical & Life Sciences at the University of Maryland, pointed out that other carotenoids that have no vitamin A activity can also have a protective effect against chronic diseases such as AMD.
Khachik has isolated and characterized roughly 50 different carotenoids in fruits and vegetables commonly consumed in the U.S. He focused on the carotenoids that do not have vitamin A activity, such as lutein, zeaxanthin, and lycopene, in an attempt to discover whether these compounds also have beneficial effects on human health. After conducting the first human supplementation studies with those three carotenoids, he discovered that they act as antioxidants in humans.
In the mid-1990s, Khachik developed a process for isolating lutein and zeaxanthin from marigold flowers. As a result of this research, lutein dietary supplements containing 5–7% zeaxanthin have been commercially available since 1995.
Khachik also discovered that in addition to lutein, zeaxanthin, and their metabolites, a wide range of dietary carotenoids accumulates in various human ocular tissues such as the retina. These carotenoids can protect the eye against AMD by acting as antioxidants and optical filters. The National Eye Institute of the National Institutes of Health is conducting an ongoing clinical trial (www.areds2.org) of approximately 4,000 participants to study the effects of oral supplementation of lutein and zeaxanthin for the treatment of AMD and cataracts.
Respiratory distress syndrome, another pressing public health issue, is caused by a lack of or insufficient lung surfactant, which is a complex mixture of lipids and proteins that helps reduce the work of breathing. Neonatal respiratory distress syndrome is a common complication in premature babies born with underdeveloped lungs. Current approaches to surfactant replacement therapy involve the use of animal products, which have worked well for premature infants but which would be too expensive to scale up for the lungs of adults suffering from acute respiratory distress syndrome.
Lee, a professor of chemistry and director of the Chicago Materials Research Center at the University of Chicago, described her lab’s efforts to develop a purely synthetic approach to surfactant replacement therapy. “But in order to really get at that, we need to understand the lipids and proteins in the native lung surfactant,” she said. “How do they work, and how do they give rise to proper lung function?” she asked.
Lee is also studying the mechanisms involved in the accumulation of β-amyloid deposits in the brain, which are associated with the development and progression of Alzheimer’s disease.
For more information about the Astellas USA Foundation Awards program, visit www.acs.org/awards and click on “Other ACS Awards.”
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