Simple and efficient capture of EGFR-expressing tumor cells using magnetic nanoparticles

Capturing tumor cells has attracted the attention because such cells can be used for diagnosing the occurrence and progression of cancers. Here we present a simple and efficient capturing of tumor cells using anti-EGFR antibody-conjugated magnetic nanoparticles. EGFR is a well-established epithelial cancer-specific marker that is over-expressed in many types of tumor cells. The conjugation of an anti-EGFR antibody with magnetic nanoparticles through a PEG-linker was shown to be highly efficient for preventing the non-specific binding of cells and improving the stability of the resulting nanoparticles even at a high salt concentration. The use of EGFR-targetable nanoparticles resulted in about 57% capture efficiency in 20 min for two cancer cell lines, PC9 (lung cancer) and HeLa (cervical cancer). The survival rate of the captured cells was approximately 85%, and most of the cells were retrievable, providing options for a further analysis of captured cells such as a mutational investigation of EGFR-related cancers. The present approach can be used for capturing circulating tumor cells (CTCs) expressing EGFR and the subsequent diagnostic analysis of the captured cells.