A novel 3D microdevice for the in vivo capture of cancer‐associated cells

Circulating tumour cells (CTCs) correlate by their number to the lethal potential of the tumour and can be characterized in terms of molecular properties. The repeated isolation of living CTCs has now appeared as an unavoidable step towards their use as biomarkers in clinical routine. We introduce a 3D stealthy microdevice adapted to the in vivo capture of CTCs in the venous blood flow, on the basis of their physical characteristics, size and rigidity. Embedded in a fluidic bench mimicking an artificial arm vein, it readily captured human prostate cancer cells spiked into donor blood down to a concentration of 1,000 cells/ml. The isolation of cancer cells in venous circulation was validated in an animal model in vivo. These results open new avenues to the characterization of CTCs in prognosis, personalization of treatments and follow‐up, not only as a research tool, but also for repeated monitoring in clinical practice.