A Chemical Method for Specific Capture of Circulating Tumor Cells Using Label-Free Polyphenol-Functionalized Films

The capture of circulating tumor cells (CTCs) mainly depends on the biological affinity and differences in physical properties between tumor cells and peripheral blood mononuclear cells (PBMCs), but the effective capture of CTCs using only a chemical method is still rare. Inspired by the excellent anti-inflammatory effects of polyphenols, we used polyphenol tannic acid-functionalized (TA-functionalized) film to develop a simple and yet effective chemical strategy for label-free capture of CTCs. The film could be easily prepared within minutes by metal–polyphenol coordination interaction while tactfully integrating the effects of repelling PBMC adhesion and enhancing cancer cell adhesion. The galloyl groups of TA were found to play a crucial role in the enhanced adhesion of cancer cells to the film. As a result of the preference of TA film for cancer cells over PBMCs, the film could effectively capture a broad range of cancer cells without the aid of capture antibodies (yield >76%). Importantly, the viability of the captured cells was as high as 90%, which is conducive to subsequent biological assays. This easy and label-free platform would provide new clues for developing chemical-based CTC capture methods and open up opportunities in designing next-generation devices for the detection and analysis of CTCs.