Drug resistance is one of the major challenges for successful cancer treatment. Intratumoral cell heterogeneity is found to be the major cause of drug resistance. Therefore, identification of cancer cells resistant to drug is crucial for the development of better curative drugs. However, identifying these cells in a heterogeneous cell population is difficult with existing technologies; thereof novel methodologies are needed in order to identify and characterize resistance cancer cells in a heterogeneous population. To address this gap, we developed nanopipette-based sensors for intracellular assessment of metabolic activity at single-cell level. Nanopipette technology was employed to develop intracellular pH and glucose nanosensors to perform at a single-cell level. Intracellular pH plays an essential role in regulation of cellular behavior while glucose is the most abundant energy supply for cells; both species may be utilized as a marker for peculiar cell in a heterogeneous population. Nanosensors display direct real-time single-cell manipulation capability with high sensitivity and selectivity while providing high spatial resolution and low invasiveness due to their small sizes. In this presentation, fabrication, characterization and in vitro pH and glucose measurements of functionalized nanopipettes will be discussed. The newly developed intracellular pH and glucose measurement technique applied to several cancer cell lines, as a proof-of-concept, will be presented. Results of these assays showed evidence of metabolic heterogeneity of different cell lines. We are expanding the use of nanosensors for single-cell nanometabolomics to study intracellular variation of these metabolites over the course of drug exposure. Changes in the metabolome over time can help identification of outlier cells and those cells can be sequenced to investigate their genomic or transcriptomic differences.

Direct investigation of metabolomics at single-cell level with nanopipettes

251st National Meeting (2016)

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