Microfluidic System Consisting of a Magnetic 3D-Printed Microchannel Filter for Isolation and Enrichment of Circulating Tumor Cells Targeted by Anti-HER2/MOF@Ferrite Core–Shell Nanostructures: A Theranostic CTC Dialysis System

Low number of circulating tumor cells (CTCs) in the blood samples and time-consuming properties of the current CTC isolation methods for processing a small volume of blood are the biggest obstacles to CTC usage in practice. Therefore, we aimed to design a CTC dialysis system with the ability to process cancer patients' whole blood within a reasonable time. Two strategies were employed for developing this dialysis setup, including (i) synthesizing novel in situ core–shell Cu ferrites consisting of the Cu-CuFe2O4 core and the MIL-88A shell, which are targeted by the anti-HER2 antibody for the efficient targeting and trapping of CTCs; and (ii) fabricating a microfluidic system containing a three-dimensional (3D)-printed microchannel filter composed of a polycaprolactone/Fe3O4 nanoparticle composite with pore diameter less than 200 μm on which a high-voltage magnetic field is focused to enrich and isolate the magnetic nanoparticle-targeted CTCs from a large volume of blood. The system was assessed in different aspects including capturing the efficacy of the magnetic nanoparticles, CTC enrichment and isolation from large volumes of human blood, side effects on blood cells, and the viability of CTCs after isolation for further analysis. Under the optimized conditions, the CTC dialysis system exhibited more than 80% efficacy in the isolation of CTCs from blood samples. The isolated CTCs were viable and were able to proliferate. Moreover, the CTC dialysis system was safe and did not cause side effects on normal blood cells. Taken together, the designed CTC dialysis system can process a high volume of blood for efficient dual diagnostic and therapeutic purposes.