Fishing antitumor ingredients by G-quadruplex affinity from herbal extract on a three-phase-laminar-flow microfluidic chip.

A new method for fishing antitumor ingredients by G-quadruplex recognition from Macleaya cordata seeds extracts was established using a three-phase-laminar-flow-chip (TPL chip). The TPL chip integrated the separation of drugs from the complex ingredients and organic solvent extraction, simplifying pretreatment processes and reducing reagents and time. In addition, the chip method showed a lower false negative result, owing to the gentle membrane-free filtration process based on diffusion separation in microchannel. Four ligands with high content in alkaloids of Macleaya cordata seeds were selected, those are chelerythrine (CHE), sanguinarine (SAN), protopine (PRO), and allocryptopine (ALL), which demonstrated affinity with G-quadruplex and were potential for antitumor.

Simultaneous determination of free and total paclitaxel in blood in a three-phase laminar flow microchip.

In this study, a three-phase laminar flow microfluidic chip (TPL chip) combined with HPLC was developed for monitoring free and total concentrations of paclitaxel (PTX) in blood simultaneously. A diluted whole blood sample (aqueous phase) was introduced into the chip, ethyl acetate (organic phase) was introduced into the chip for extraction, and an interphase was used to prevent the blood sample from coming into direct contact with the organic phase. Because only free drug can quantitatively diffuse into the organic extraction phase and the free drug fraction has a linear relationship with the dilution factor of blood, both the free and total drug concentrations can be obtained by detecting the concentration of paclitaxel in the organic extraction phase. The governing factor such as flow rate for extraction was optimized. Docetaxel was used as an internal standard. The reliability of the quantitative diffusion of molecules in the TPL chip was proved by the methodological investigation of PTX in PBS sample, which showed a good linearity in the concentration range of 0.5 - 100 µg/mL and a detection limit of 7 ng/mL. Good repeatibilities for retention time (RSD of PTX is 1.23%, docetaxel is 1.14%, n = 5) and peak area ratio of PTX to docetaxel (RSD is 4.38%) were obtained. For blood sample analysis, only 100 µL of sample was needed and whole pretreatment was finished in 35 min, and a recovery of 94~117% were obtained. The provided method showed advantages in fast analysis speed, minimum sample handing, and potential ability of automation, and integration.