Circulating tumor cells (CTCs) in peripheral blood provide valuable genetic information for cancer diagnosis and overall disease monitoring. The analysis of “liquid biopsy” holds immense promise, as it may lead to new approaches for cancer treatment.

This study reports an effective continuous-flow microchannel system for isolating CTCs using a transferrin-conjugated 3D matrix synthesized by crosslinking polyethylene glycol–Fe₃O₄ nanostructures. This design enables rapid and efficient capture of CTCs. The platform also allows the use of multiple microchannel units in series, which can enhance cell capture efficiency by increasing the frequency of cell–substrate contact.

CTCs were captured with high efficiency even at low target cell concentrations, achieving approximately 90% capture efficiency at 25 cells per mL of blood. Furthermore, the study demonstrates that cell capture performance is influenced by topographic interactions between the nanostructure-based matrix and the cancer cells of interest.

In addition, this work presents a proof of concept using a 3D microchannel system capable of simultaneously capturing and permanently eliminating CTCs from peripheral blood samples. The study also evaluates clinical samples from colon and breast cancer patients for the rapid isolation of CTCs.

Conclusively, the platform demonstrates a strong capacity for cancer cell sorting, biological studies of CTCs, and investigation of cancer metastasis, potentially benefiting real-time liquid biopsy applications and early cancer prognosis.