NEWS OF THE W EEK
CONGRESS INVESTIGATES TAINTED HEPARIN FDA: Lawmakers probe agency’s
foreign plant inspections
BAXTER HEALTHCARE
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APITOL HILL LAWMAKERS have launched an investigation into the events leading up to the distribution of contaminated batches of the blood-thinning drug heparin. The lots of heparin, whose active pharmaceutical ingredient (API) was made in China, have been linked to multiple deaths and hundreds of serious allergic reactions in the U.S. FDA has identified the contaminant as oversulfated chondroitin sulfate, a chemical that does not occur naturally (C&EN, March 24, page 13). A House Energy & Commerce Committee panel plans to hold hearings in April to examine issues surrounding the matter. Congressional investigators have been sent to Scientific Protein Laboratories (SPL) in Waunakee, Wis., to interview company officials. SPL co-owns a production facility in Changzhou,
THE SECRET OF IVY’S STICKING POWER NANOSCIENCE: Creeping vine secretes adhesive nanoparticles
SHUT TERSTO CK
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N ANOTHER EXAMPLE of nature making the
most of nanotechnology, scientists have discovered that ivy uses organic nanoparticles to cling to and climb up virtually any surface (Nano Lett., DOI: 10.1021/ nl0725704). The small and flexible nanoparticles fit easily into even the tiniest crevices, thereby allowing ivy to generate enough force for climbing and giving it an incredible affixing power, which anyone who has ever tried to remove the resilient vine can attest to. According to the researchers, engineers could exploit this novel adhesive mechanism for a range of engineering applications, including the development of climbing robots. Mingjun Zhang, the University of Tennessee, Knoxville, engineering professor who spearheaded the research, got the idea to study ivy while watching his son play outside one afternoon. He noWWW.C E N- ONLI NE .ORG
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China, and is a supplier of heparin API to Baxter Healthcare and B. Braun Medical, two U.S. companies that make and distribute the finished product. Baxter recalled nearly all of its heparin in February, and B. Braun said on March 21 that it was recalling 23 lots of the drug as a precautionary measure. Similar recalls of Chinesesourced heparin have happened in Europe and Japan. “This latest development underscores our concerns that FDA does not have a robust enough presence overseas in conducting inspections in plants that make drugs for the U.S. market,” Energy & Commerce Committee Chairman John D. Dingell (D-Mich.) says. “Ongoing surveillance inspections are critical.” Rep. Bart Stupak (D-Mich.), who leads the committee’s panel on oversight and investigations, says contaminated heparin is the second instance in the past year of “what appears to be intentional adulteration of food and drugs coming into this country from China.” Melamine was detected in imported Chinese pet food last year. “We need better processes for inspecting all foreignmade food and drugs, but at a minimum we must address the China issue now,” Stupak says. “The sad reality is that FDA’s inability to inspect foreign facilities has put American lives at risk. Our hearings will evaluate what went wrong leading up to the heparin recall and the role increased overseas inspections by FDA could play in preventing future incidents.”—GLENN HESS
ticed how the plant had woven its way around a nearby fence and wondered what the source of its climbing prowess was. Zhang wasn’t able to find much in the literature to satisfy his curiosity, aside from an 1876 report from Charles Darwin noting that ivy rootlets secrete a yellowish matter while climbing a surface. To get an idea of what makes this material stick, Zhang’s lab coaxed ivy into growing onto silicon and mica surfaces and then studied the secretions with optical and atomic force microscopy. “We were very surprised to see nanoparticles,” Zhang says of the mass of highly uniform particles roughly 70 nm in diameter that the secretions contained. Analysis with high-performance liquid chromatography revealed that the nanoparticles are made up of a complex mix of organic compounds. Zhang’s team, including Maozi Liu, Harry Prest, and Steve Fischer of Santa Clara, Calif.based Agilent Technologies, was able to determine the formulas for the 19 most prevalent compounds, although the team has not yet determined their structures. “It is fascinating how plants make use of nanotechnology for their livelihood,” comments Jeffrey M. Karp, a biomaterials and nanotechnology expert at Harvard Medical School. “Clearly this work provides an opportunity for inspiration that can be applied to solving human problems through biomimetic approaches. Although it is still early, harnessing nanoparticles capable of similar levels of adhesion through hydrogen-bonding mechanisms could be useful to design new industrial and medical adhesives.”—BETHANY HALFORD
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