Characterization of a novel microfluidic platform for the isolation of rare single cells to enable CTC analysis from head and neck squamous cell carcinoma patients.

Detailed examination of tumor components is leading-edge to establish personalized cancer therapy. Accompanying research on cell-free DNA, the cell count of circulating tumor cells (CTCs) in patient blood is seen as a crucial prognostic factor. The potential of CTC analysis is further not limited to the determination of the overall survival rate but sheds light on understanding inter- and intratumoral heterogeneity. In this regard, commercial CTC isolation devices combining an efficient enrichment of rare cells with a droplet deposition of single cells for downstream analysis are highly appreciated. The Liquid biopsy platform CTCelect was developed to realize a fully-automated enrichment and single cell dispensing of CTCs from whole blood without pre-processing. We characterized each process step with two different carcinoma cell lines demonstrating up to 87 % enrichment (n = 10) with EpCAM coupled immunomagnetic beads, 73 % optical detection and dispensing efficiency (n = 5). 40 to 56.7 % of cells were recovered after complete isolation from 7.5 ml untreated whole blood (n = 6). In this study, CTCelect enabled automated dispensing of single circulating tumor cells from HNSCC patient samples, qPCR-based confirmation of tumor-related biomarkers and immunostaining. Finally, the platform was compared to commercial CTC isolation technologies to highlight advantages and limitations of CTCelect . This system offers new possibilities for single cell screening in cancer diagnostics, individual therapy approaches and real-time monitoring.
Competing Interests: The authors have declared no conflicts of interest. All authors have read and agreed to the published version of the manuscript.
(© 2022 The Authors. Engineering in Life Sciences published by Wiley‐VCH GmbH.)