Aptamer-conjugated gold nanorod for photothermal ablation of epidermal growth factor receptor-overexpressed epithelial cancer

Biomarker-specific photothermal nanoparticles that can efficiently sense markers that are overexpressed in distinguished adenocarcinomas have attracted much interest in an aspect of efficacy increase of cancer treatment. We demonstrated a promising prospect of a smart photothermal therapy agent employing anti-epidermal growth factor receptor aptamer (Apt(EGFR))-conjugated polyethylene glycol (PEG) layted gold nanorods (Apt(EGFR)-PGNRs). The cetyltrimethylammonium bromide bilayer on GNRs was replaced with heterobifunctional PEG (COOH-PEG-SH) not only to serve as a biocompatible stabilizer and but also to conjugate Apt(EGFR). Subsequently, to direct photothermal therapy agent toward epithelial cancer cells, the carboxylated PEGylated GNRs (PGNRs) were further functionalized with Apt(EGFR) using carbodiimide chemistry. Then, to assess the potential as biomarker-specific photothermal therapy agent of synthesized Apt(EGFR)-PGNRs, the optical properties, biocompatibility, colloidal stability, binding affinity, and epicellial cancer cell killing efficacy in vitro/in vivo under near-infrared laser irradiation were investigated. As a result, Apt(EGFR)-PGNRs exhibit excellent tumor targeting ability and feasibility of effective photothermal ablation cancer therapy. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)