Cetuximab-modified doxorubicin bovine serum albumin nanoparticles for the treatment of epidermal growth factor receptor-overexpressing colon cancer cells

Abstract

In this study, we developed an active targeting nano-immunoplatform of doxorubicin (DOX)-loaded bovine serum albumin (BSA) modified with the humanized antibody cetuximab, which can target the epidermal growth factor receptor (EGFR) of EGFR-overexpressing colon cancer, and subjected it to a series ofin vitroevaluation. The obtained cetuximab-modified nanoparticles (cetuximab-DOX-immuno-NPs) had an average particle size of 218.2±2.2 nm, a polydispersity index of 0.162±0.023, a zeta potential of −23.28±0.75 mV, and a cetuximabloading efficiency of 33.6%±3.5%. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity experiments showed that the cytotoxic of cetuximab-DOX-immuno-NPs in EGFR-overexpressing RKO colon cancer cells was significantly higher than it was in EGFR-under-expressing LS174 T cells. The results of flow cytometry showed that when DOX-immuno-NPs were used, DOX was eliminated soon after entering the cells, whereas when cetuximab-DOX-immuno-NPs were used, DOX efflux was reduced. Confocal laser-scanning microscopy was used to visualize the endocytosis of nanoparticles, and revealed that the fluorescence intensity of cetuximab-DOX-immuno-NPs was significantly higher than that of non-specific IgG-DOX-immuno-NPs in RKO cells. Moreover, in EGFR-under-expressing LS174 T cells, both cetuximab-DOXimmuno-NPs and Immunoglobulin G-DOX-immuno-NPs showed weak DOX fluorescence intensity, reflecting the specificity and selectivity of cetuximab-modified nanoparticles toward EGFR-overexpressing cancer cells. This study demonstrated that cetuximab modification of DOX-loaded BSA nanoparticles can increase their selectivity and reduce their toxicity. As this would decrease the side effects of these treatments in patients, this study shows that cetuximab-modified doxorubicin-loaded bovine serum albumin nanoparticles are promising candidates for targeted colon cancer therapy.