A Cascaded Phase-Transfer Microfluidic Chip with Magnetic Probe for High-Activity Sorting, Purification, Release, and Detection of Circulating Tumor Cells.

Microfluidic chips have emerged as a promising tool for sorting and enriching circulating tumor cells (CTCs) in blood, while the efficacy and purity of CTC sorting greatly depend on chip design. Herein, a novel cascaded phase-transfer microfluidic chip was developed for high-efficiency sorting, purification, release, and detection of MCF-7 cells (as a model CTC) in blood samples. MCF-7 cells were specifically captured by EpCAM aptamer-modified magnetic beads and then introduced into the designed cascaded phase-transfer microfluidic chip that consisted of three functional regions (sorting, purification, and release zone). In the sorting zone, the MCF-7 cells moved toward the inner wall of the channel and entered the purification zone for primary separation from white blood cells; in the purification zone, the MCF-7 cells were transferred to the phosphate-buffered saline flow under the interaction of Dean forces and central magnetic force, achieving high purification of MCF-7 cells from blood samples; in the release zone, MCF-7 cells were further transferred into the nuclease solution and fixed in groove by the strong magnetic force and hydrodynamic force, and the continuously flowing nuclease solution cleaved the aptamer on the trapped MCF-7 cells, causing gentle release of MCF-7 cells for subsequent inductively coupled plasma mass spectrometry (ICP-MS) detection or further cultivation. By measurement of the endogenous element Zn in the cells using ICP-MS for cell counting, an average cell recovery of 84% for MCF-7 cells was obtained in spiked blood samples. The developed method was applied in the analysis of real blood samples from healthy people and breast cancer patients, and CTCs were successfully detected in all tested patient samples (16/16). Additionally, the removal of the magnetic probes on the cell surface significantly improved cell viability up to 99.3%. Therefore, the developed cascaded phase-transfer microfluidic chip ICP-MS system possessed high integration for CTCs analysis with high cell viability, cell recovery, and purity, showing great advantages in early clinical cancer diagnosis.

Efficient preparation of hyperoside and quercitrin from Zanthoxylum bungeanum Maxim leaves using an integrated surfactant-based aqueous two-phase system, back-extraction and adsorption separation.

Zanthoxylum bungeanum leaves (ZBL) are of great medicinal value for being rich in hyperoside and quercitrin. In this study, a novel, efficient and economical continuous process was established. First, aqueous two-phase system (ATPS) composed of Triton X-100/(NH4)2SO4 was employed to enrich hyperoside and quercitrin from ZBL extracts and the recoveries reached 98.53% and 99.12%. Then back-extraction with dichloromethane-water system was adopted to separate hyperoside and quercitrin from Triton X-100 micelles which were recycled and the recoveries reached 86.58% and 85.19%. Finally, S-8 macroporous resin was used for removing the salt introduced in ATPS and the final recoveries reached 82.38% and 81.81%, much higher than the total flavonoids recovery as 69.08%. Furthermore, scale-up experiment certified that the continuous process was feasible for industrial production. Efficiently and economically, this method achieved a great breakthrough in purity and provided a novel reference for further purification and phase-forming component recycle.