With the aim to design addressable magnetically-active carbon nanotubes (CNTs) for cancer treatment, the use of Fe-fi lled CNTs (Fe@MWCNTs) as multifunctional scaffolds is reported for exohedrally anchoring a monoclonal antibody (mAb) known to bind a plasma membrane receptor over-expressed in several cancer cells (EGFR). Comprehensive microscopic (transmission electron microscopy, atomic force microscopy, and scanning electron microscopy) and spectroscopic (Raman, 57 Fe Mossbauer, energy dispersive spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction) characterizations reveal the effi cient confi nement of magnetically-active Fe phases ( α -Fe and Fe 3 C), while compositional evaluations through XPS, thermogravimetric analysis and gel electrophoresis confi rm that mAb immobilization onto Fe@MWCNTs occurs.
Enzyme-linked immunosorbent assay (ELISA), confocal microscopy imaging and western blotting confi rm the targeting action toward EGFR-overexpressing cell lines (EGFR + ). In vitro magnetic fi ltration experiments demonstrate that a selective removal of EGFR + cells from a mixed population of healthy cell linescould be obtained in very short times ( ≈ 10 min). Cytotoxicity evaluations by classic cell staining procedures after application of an electromagnetic radiation inducing magnetic fl uid hyperthermia (MFH), show a selective suppression of the EGFR + cell line. Molecular dynamics and docking simulations of the hybrid mAb/Fe@MWCNTs conjugates nicely show how the presence of the CNT framework does not sterically affect the conformational properties of the two antigen binding regions, further supporting the biochemical fi ndings.