The scientists also fitted some nanowires in the arrays with nucleic acid receptors for telomerase, an enzyme inactive in most of the body's somatic cells but active in at least 80 percent of known human cancers. In testing of extracts from as few as 10 tumor cells, these receptors allowed real-time monitoring of telomerase binding and activity.
Lieber says nanowire arrays could easily be scaled up to detect many different cancer markers -- more of which are being found all the time, thanks to the current boom in proteomics. Widespread use of these cancer markers in healthcare will ultimately depend upon the development of techniques that allow rapid detection of many markers with high selectivity and sensitivity.
"Genomics and proteomics research has elucidated many new biomarkers that have the potential to greatly improve disease diagnosis," the scientists write. "The availability of multiple biomarkers is believed to be especially important in the diagnosis of complex diseases like cancer, for which disease heterogeneity makes tests of single markers inadequate. Patterns of multiple cancer markers might, however, provide the information necessary for robust diagnosis of disease ?[and] detection of markers associated with different stages of disease pathogenesis could further facilitate early detection."
While initial rounds of cancer testing today identify only whether or not cancer is present, nanowire arrays have the potential to immediately fill in details on exactly what type of cancer is present. Nanowires could also track patients' health as treatment progresses. Because the arrays detect molecules suspended in fluids, drops of blood could be tested directly, in a physician's office, without any need for biochemical manipulation.
Lieber's co-authors are Gengfeng Zheng, Fernando Patolsky, Yi Cui and Wayne
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Source:Harvard University