Nanowire Biosensors for Detection of Cancer Biomarkers

Nanowires can electronically detect a few proteins molecules along with other biomarkers that are early signs of cancer. Nanowire sensors are in development at California Institute of Technology (Pasadena, CA) for very early diagnosis of cancer, when there are just a few thousand cells. Nanowires in a set are coated with different compounds, each of which binds to a particular biomarker, and changes the conductivity of the nanowire that can be measured. Thousands of such nanowires are combined on a single chip that enables identification of the type of cancer. Currently such a chip can detect between 20 to 30 biomarkers and is being used for the early diagnosis of brain cancer.

NP-Peptide Complexes for Detection of Cancer Biomarkers in Urine

Exogenously administered ‘synthetic biomarkers’ composed of mass-encoded peptides conjugated to nanoparticles (NPs) have been developed for noninvasive urinary monitoring to detect cancer biomarkers (Kwong et al. 2012). The NP complexes accumulate at the tumor site, where matrix metalloproteinases (MMPs) from cancer cells are expected to cleave the NP-bound peptides, releasing them into the bloodstream. The peptides would then accumulate in the kidneys and be excreted in the urine, which could be analyzed using MS. The NPs are engineered to express 10 different peptides, each with a specific corresponding MMP and size making them distinguishable by MS. In mouse models of liver cancer, these agents were shown to substantially improve early detection of cancer compared with current clinically used blood biomarkers. This method has potential for development as point-of-care diagnostics to detect metastasis and measure tumor response to chemotherapy.

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