Selective, user-friendly, highly porous, efficient, and rapid (SUPER) filter for isolation and analysis of rare tumor cells

Rapid, efficient, and selective separation of tumor cells from complex body fluids is urgently needed for clinical application of tumor-cell-based liquid biopsy. Herein, a size-selective affinity filtration system, named Selective, User-friendly, highly Porous, Efficient, and Rapid filter (SUPER Filter), was developed for high-performance tumor cell isolation and analysis. SUPER Filter enabled selective interaction of tumor cells with size-optimized and antibody-coated micropore walls during filtration, achieving high efficiency of 91.0 ± 6.1% in PBS and 83.7 ± 6.4% in whole blood. Meanwhile, its larger micropore size than traditional filtration devices greatly reduced nonspecific capture of background cells (55-126 cells/mL blood) with enrichment factors of 1.1 × 104 - 1.0 × 105 and purity of 52.7 ± 4.2%. Moreover, its high porosity enabled ultra-fast (< 5 s for 1 mL of blood or 10 mL of buffer samples) and user-friendly gravity-driven filtration. Finally, SUPER Filter demonstrated rapid, efficient, and selective separation of tumor cells from blood and large-volume pleural and ascetic fluid samples of cancer patients for morphological and molecular analysis. We expect that this size-selective affinity filtration strategy facilitates clinical application of tumor-cell-based liquid biopsy.