Fig. 1

The 3D Ni/PLGA micro-/nano-chip local topographic interactions among the micropillars, nanofibers and CTCs. The SEM images of a, b Ni micropillars, c PLGA nanofibers and d MCF7 cells were captured on 3D Ni/PLGA micro-/nano-chip. FDA fluorescence micrographs of target cells were captured on e Ni micropillars substrate, f PLGA nanofibers substrate and g 3D Ni/PLGA patterned substrate