EGFR-specific single-chain variable fragment antibody-conjugated Fe(3)O(4)/Au nanoparticles as an active MRI contrast agent for NSCLC

Overexpression of epidermal growth factor receptor (EGFR) is closely associated with a poor prognosis in non-small cell lung cancer (NSCLC), thus making it a promising biomarker for NSCLC diagnosis. Here, we conjugated a single-chain antibody (scFv) targeting EGFR with Fe(3)O(4)/Au nanoparticles to form an EGFR-specific molecular MRI bioprobe (scFv@Fe(3)O(4)/Au) to better detect EGFR-positive NSCLC tumors in vivo. In vitro, we demonstrated that the EGFR-specific scFv could specifically deliver Fe(3)O(4)/Au to EGFR-positive NSCLC cells. In vivo experiments showed that the accumulation of scFv@Fe(3)O(4)/Au in tumor tissue was detectable by magnetic resonance imaging (MRI) at the indicated time points after systemic injection. The T2W signal-to-noise ratio (SNR) of EGFR-positive SPC-A1 tumors was significantly decreased after scFv@Fe(3)O(4)/Au injection, which was not observed in the tumors of mice injected with BSA@Fe(3)O(4)/Au. Furthermore, transmission electron microscopy (TEM) analysis showed the specific localization of scFv@Fe(3)O(4)/Au in the SPC-A1 tumor cell cytoplasm. Collectively, the results of our study demonstrated that scFv@Fe(3)O(4)/Au might be a useful probe for the noninvasive diagnosis of EGFP-positive NSCLC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10334-021-00916-1.