Optical Hyperthermia Using Anti-Epidermal Growth Factor Receptor-Conjugated Gold Nanorods to Induce Cell Death in Glioblastoma Cell Lines

Abstract

Gold nanorods (GNRs) are able to efficiently convert absorbed light into localized heat within a short period of time due to the surface plasmon resonance effect. This property, along with their easy bioconjugation, allows the use of GNRs in photothermal therapy as selective photothermal agents to target cancer cells. In this study, GNRs were combined with an antibody against anti-epidermal growth factor receptor (EGFR), a receptor that is frequently overexpressed in brain tumors, and the potential of the nanoconjugate (EGFR-GNRs) to eliminate tumor cells was assessed in vitro. Two human glioblastoma cell lines (U373-MG and 1321N1) expressing EGFR at different levels were incubated with unfunctionalized GNRs and EGFR-GNRs, and then exposed to irradiation with a continuous-wave laser at 808 nm. The pretreatment with the EGFR-GNR nanoconjugate significantly increased the cell death rate after laser irradiation compared to unconjugated GNRs. No photothermal cell destruction was observed in the absence of GNRs. Our data suggest that the EGFR modification improves GNR-mediated cell death after laser irradiation, even when EGFR is present at low doses in cancer cells, and may have the potential to be used clinically as a tool to help complete resection of brain tumors during surgery.