(229p) Adhesion-Based Tumor Cells Capture Using Nanotopography

Circulating tumor cells (CTCs) shed from primary tumors, transport through the blood stream to distant sites, and cause 90% of cancer deaths. Although different techniques have been developed to isolate CTCs for cancer detection, diagnosis and treatment, the heterogeneity of expression of the target antigen and the significant size variance in CTCs limit clinical applications of antibody- and size-based isolation techniques. Cell adhesion using nanotopography has been suggested as a promising approach to isolate CTCs independent of surface marker expression or size of CTCs. However, the influence of nanotopography configuration (geometry and dimensions) on CTC capture efficiency has not been fully investigated. This study examined capture performance of several cancer cell lines of different types, surface marker expression and metastatic status on nanotopographies of various geometries and dimensions. The cancer cells exhibited differential capture performance with an efficiency up to 52% on the nanotopographies without antibody conjugation. Compared with flat surfaces and isotropic, discrete nanopillars, anisotropic nanogratings favored cancer cell adhesion, thus improving the capture efficiency. The cancer cells were less sensitive to the height range studied. By optimizing the nanotopography configuration and performing appropriate surface modification, the CTC capture efficiency was further improved. This study is expected to shed light on optimization of nanotopography to improve adhesion-based CTC capture technique.