Drug response of captured BT20 cells and evaluation of circulating tumor cells on a silicon nanowire platform.

Research on specific drug responses of circulating tumor cells (CTCs) provides very important information for treatment of cancer patients at a patient-specific level. For this reason, platforms for high capture efficiency of CTCs are essential for clinical evaluation of patient-specific drug responses of CTCs. Recently, nanostructure based platforms have been developed with a high capture efficiency of more than 93% due to high-affinity binding and the 3D nanotopographic features of the nanostructure substrate. In this study, the breast carcinoma cell-line (BT20) cells with an ultra-low abundance range were captured by streptavidin (STR)-functionalized silicon nanowire (SiNW) platforms for evaluation of capture efficiency. A capture efficiency of more than 90% was achieved. Specific drug responses of BT20 cells captured on STR-SiNW platforms were analyzed using tamoxifen or docetaxel as a function of incubation time and dose, and compared with a 96-well plate platform. The drug responses of CTCs on STR-SiNW platforms were more sensitive than a 96-well plate platform. In addition, CTCs were successfully captured and evaluated their size distribution from the blood of breast cancer patients using fluorescence imaging. In conclusion, we suggest that the SiNW platform is adaptable for clinical use in evaluation of CTCs and drug response tests.