Circulating tumor cells enrichment and phenotyping by combining dielectrophoresis and metasurface-enhanced infrared spectroscopy (Conference Presentation)

All-optical label-free approaches to phenotyping neoplastic cells can have a significant impact on clinical outcomes. One specific example is the so-called liquid biopsy, where small numbers of circulating tumor cells (CTCs) present in the blood are collected, counted, enriched, and analyzed. The obtained data provides important information about disease progression and prognosis, the aggressiveness of the metastatic cancer, the efficacy of the administered therapies, and the locations of primary and secondary tumors. CTCs are also emerging as an important biomarker for personalized therapy. One practical challenge is that the numbers of CTCs in whole blood is very small compared with other blood components (only one per million of leucocytes during the early stage of the metastatic progression). The second challenge is that the most approaches to capturing and counting the CTCs involve antibodies that bind to specific cancer cell markers. Those can evolve because of the heterogeneity of CTCs. Therefore, label-free approaches are needed. In this talk I will show how two physical tools, metallic AC electrodes for DEP cells capture, and plasmonic metasurfaces for enhanced mid-infrared reflection spectroscopy, can be combined to simultaneously capture the CTCs, and to spectroscopically phenotype them. The integration of the electrically-biased metasurfaces with microfluidics will be explained, and preliminary results based on dielectric beads and cultured cell lines (A431 skin carcinoma cells) will be presented in this talk. Future directions will be outlined.