Efficient Detection and Single-Cell Extraction of Circulating Tumor Cells in Peripheral Blood.

Circulating tumor cells (CTCs) play an important role in cancer biology studies. To further elucidate the role of single CTCs in tumor metastasis and prognosis, effective methods must be developed to isolate and encapsulate single CTCs. In this work, a single CTC capture and encapsulation platform based on ZnO nanofibers and surface acoustic waves was constructed. We also demonstrated that this platform can capture and encapsulate single CTCs efficiently. We first validated that the dense ZnO nanofibers provide additional binding sites, resulting in an increased capture efficiency of up to 93.3%. We then demonstrated that the release efficiency was increased to 100% by dissolving the substrate with ultralow concentration (25 mM) phosphoric acid, and the activity of the released cells was not affected. Furthermore, the released cells were suspended in alginate solution and encapsulated single CTCs via droplet-based surface acoustic wave devices. The encapsulating rate of a single cell is up to 13% under a pulse width duration of 520 μs. Few technology based on nanofibers and acoustic tweezers for single-cell encapsulation via acoustic droplet vaporization has been reported. It has a wide range of potential applications to acquire single target cells, which may facilitate further early clinical diagnosis and treatment of cancer patients.