The physicochemical and biological characterization of a 24-month-stored nanocomplex based on gold nanoparticles conjugated with cetuximab demonstrated long-term stability, EGFR affinity and cancer cell death due to apoptosis.

Nanotechnology is one of the most promising tools for future diagnosis and therapy. Thus, we have produced gold nanoparticles coated with cetuximab at a dose-range from 5 µg up to 200 µg, and prolonged stable nanocomplexes were obtained. The nanocomplexes were characterized by UV-Vis, zeta potential, TEM, fluorometry, infrared regions, XPS and atomic absorption spectrometry. For biological characterization the A431 cell line was used. Cellular uptake, target affinity and cell death were assessed using ICP-OES, immunocytochemistry and flow cytometry, respectively. The immobilization of cetuximab on the AuNPs surfaces was confirmed. The nanocomplex with 24 months of manufacturing promoted efficient EGFR binding and induced tumour cell death due to apoptosis. Significant (p < 0.05) cell death was achieved using relatively low cetuximab concentration for AuNPs coating compared to the antibody alone. Therefore, our results provided robust physicochemical and biological characterization data corroborating the cetuximab-bioconjugate AuNPs as a feasible nanocomplex for biomedical applications.