Bioinspired three-dimensional hierarchical micro/nano-structured microdevice for enhanced capture and effective release of circulating tumor cells

The efficient capture and release of the circulating tumor cells (CTCs) are promising for the CTC related cancer diagnosis and subsequent analysis. However, it is a great challenge to isolate and enrich the rare CTCs from the complex peripheral blood sample, which inhibits its broad translating to the clinical applications. Although various papers reported that the nanostructure substrates can improve the capture efficiency of CTCs, few of researches constructed 3D hierarchical micro/nano-structured microdevice to enhance the efficiency of CTC capture and release with a simple manner. Herein, a bio-inspirited 3D epithelial cell adhesion molecule (EpCAM) aptamer modified rose petal derived ZnO microchip (EpCAM-RPD-ZnO-Chip) was designed to realize efficient capture and release of the CTCs. The 3D rough spherical concave surfaces on the EpCAM-RPD-ZnO-Chip guaranteed the maximum contact with the CTCs, thus improving the capture efficiency. Moreover, simple release of CTCs by dissolving ZnO under moderate acidic condition was achieved. The topographical and target molecular recognition cooperatively contributed to highly efficient capture of CTCs. The scanning electron microscope (SEM) image clearly showed that the filopodias and lamellipodias of CTCs stretched and attached to the ZnO nanomaterials. In sum, the proposed 3D EpCAM-RPD-ZnO-Chip is expected to be a promising tool for capture and release of CTCs in clinical trials, which might lay a foundation for downstream analysis and precise drug susceptibility test for the cancer treatment.