Electrical Profiling and Aptamer Functionalized Nanotextured Surface in a Single Biochip for the Detection of Tumor Cells

Abstract

Early detection and accurate enumeration of rare tumor cells in the peripheral blood of cancer patients has enormous diagnostic potential. Highly sensitive approaches are needed for screening and timely diagnosis due to the scarcity of circulating tumor cells (CTCs) at early stages of cancer. Microfluidic devices have emerged as important platforms to detect and quantify tumor cells. This article reports a nanotextured microfluidic device to capture tumor cells with surface grafted anti-EGFR RNA aptamers coupled with translocation behavior based enumeration. Nanotextured polydimethylsiloxane (PDMS) surface was functionalized with aptamers to capture human glioblastoma (hGBM) cells while microchannels on either side of the capture region discriminated tumor cells based on their translocation behavior at single cell level. The translocation profile depended on mechanophysical properties of the cells. First of all, cell capture efficiency and translocation behavior of tumor and blood cells were determined. Eventually, tumor cells were mixed in blood at a concentration of 100 cells/ml and detected using the microfluidic device. The efficiency of the device was above 83% to detect metastatic hGBM cells from blood. The device facilitated multistage detection of tumor cells based on both their mechanophysical and biochemical properties. This lab-on-a-chip approach can be used for cancer screenings at point-of-care.