TiO nanopillar arrays coated with gelatin film for efficient capture and undamaged release of circulating tumor cells.

Circulating tumor cells (CTCs) are important for the detection and treatment of cancer. Nevertheless, a low density of circulating tumor cells makes the capture and release of CTCs an obstacle. In this work, TiO nanopillar arrays coated with gelatin film were synthesized for efficient capture and undamaged release of circulating tumor cells. The scanning electron microscope and atomic force microscope images demonstrate that the substrate has a certain roughness. The interaction between the cell membrane and the nanostructure substrate contributes to the efficient capture of CTC (capture efficiency up to 94.98%). The gelatin layer has excellent biocompatibility and can be rapidly digested by matrix metalloproteinase (MMP9), which realizes the non-destructive release of CTCs (0.1 mg ml, 5 min, nearly 100% release efficiency, activity 100%). Therefore, by our strategy, the CTCs can be efficiently captured and released undamaged, which is important for subsequent analysis.