Selective Isolation of Heterogenic Circulating Tumor Cells(CTCs) using Magnetic Gradient based Microfluidic System

Abstract

Circulating tumor cells(CTCs) is one of key marker of cancer metastasis in human body. Despite of the importance to diagnose the cancer metastasis by CTCs, still it is formidable challenge to use in the clinical purpose because of the rarity and the heterogeneity of CTCs in the cancerpatient’s peripheral blood sample. To solve those addressed limitations, we have developed magnetic force gradient based microfluidic system for isolating the total number of CTCs in the sample and characterizing the state of CTCs simultaneously with respect to the epithelial cell adhesionmolecule (EpCAM) expression level. We have synthesized magnetic nanoparticles (MNPs) using hydrothermal method and functionalized anti-EpCAM on their surface for the specific binding with EpCAM on the tumor cell membrane. The microfluidic system designed to isolate and classify the CTCs by isolating at the different location in the chip using magnetic force differences depending on the EpCAM expression level. We observed 95.7% of EpCAM positive and 79.3% of EpCAM negative CTCs isolated in the microfluidic system. At the same time, the 71.3% of isolated EpCAM positive CTCs were isolated at the first half area whereas the 76.9% of EpCAM negative CTCs were collected at the latter half area.