A University of Minnesota research team, led by electrical and computer engineering professor Jian-Ping Wang and medicinal chemistry associate professor Chengguo Xing, has demonstrated a magnetic nanotechnology-based diagnostic technique that can accurately identify disease biomarkers and detect diseases in their early stages in unprocessed human blood, saliva or urine.
This research, published in the March 31 issue of the Journal of the American Chemical Society (JACS), highlights technology that may lead to performing accurate, multiple tests enabling early detection and monitoring of chronic disease, disease reoccurrence, and therapy efficacy. Their research also paves the way for identifying bio-molecules that make up various diseases, immune defense mechanisms, environmental and biosafety monitoring.
"Our current health care system is facing an enormous financial burden mainly due to increasing cases of chronic diseases such as cancer," says Wang. "Due to the complexity of human biology and the chronic nature of cancer, it is extremely challenging to identify valid cancer biomarkers and to detect cancers in their early stages. Patients must always visit a clinic for testing. A low-cost, family-based medical device, which would allow patients to monitor cancer developments over a period of time by simply testing droplets of blood, saliva or urine for cancer biomarker changes, could have a major impact on cancer control through early detection."
Traditional detection methods, like the ELISA test, take a long time to process, require high-cost equipment and professional training of staff, and do not provide the precision needed. The new method could provide portable, low-cost, rapid, multiplex, background/matrix-insensitive and more precise testing.
The current giant magnetoresistive (GMR) detecting principle employs a sandwich-based approach and uses iron oxide nanoparticles. This method compromises the detection sensitivity and monotonicity that cannot provide an accurate quantification.
The University team demonstrated the new, two-layer detection scheme where distance of the disease biomarkers to the sensor is minimized. This two-layer approach enhances the detection over the traditional sandwich-based approach by 3.4 to 39 times, depending on the size and orientation of the antibody and protein used. The University team used their unique high-magnetic-moment nanoparticles, which are 3 to 10 times higher in signal than traditional iron oxide nanoparticles, depending on the particle size and applied field. Another key invention enabling this demonstration is their novel GMR sensor. With the integration of all these characteristics, the team demonstrated the detection of low concentration biomarker in unprocessed human sera samples based on magnetic nanotechnology for the first time. The research has been partially supported by National Science Foundation. Entities at the University of Minnesota that provided support include the Center for Nanostructure Application, Nanobiotechnology Initiative and Institute for Engineering in Medicine. For the abstract and full text of the research report, visit http://z.umn.edu/biomarker.