Fig. 5

a Schematic representation and b photograph of the microfluidic device for capturing and releasing CTCs, consisting of a PLGA nanofiber array–coated glass cover slip (as the NanoVelcro bottom substrate) and a PMMA top plate (as the chaotic mixing module). c Performance observed for the prevention of nonspecific cell adhesion (EpCAM-positive HCT116 and EpCAM-negative THP1) on random and aligned PLGA nanofiber arrays (without anti-EpCAM coating). d–f Optimization of operational parameters for purifying CTCs: Cell-capture performance d when using various concentrations of biotin–(PEG)₇–amine (50, 200, and 500 µg mL⁻¹) on random and aligned PLGA nanofiber arrays (with anti-EpCAM coating) under a flow rate of 1.5 mL h⁻¹; e at various flow rates (1, 1.5, 2, and 3 mL h⁻¹); and f at various diameter distribution of PLGA fiber arrays (500, 900, and 2500 nm)