Aptamer-conjugated gold nanostars for targeted cancer photothermal therapy

Photothermal therapy is a highly efficient and minimally invasive method for cancer therapy. To enhance the safe and effective effect of photothermal therapy, specific recognition of targeting cells and efficient direct heat transmission to cells for killing cells are quite important. In this work, aptamer-conjugated gold nanostars (Apt-AuNSs) used for targeted photothermal therapy were reported. AuNSs showed a higher photothermal conversion efficiency and excellent photostability, which has been used as a highly effective theranostic nanoprobe. Thiol-modified AS1411 aptamers, which showed the high targeting property for HeLa cells with overexpression of nucleolin, were conjugated to AuNSs through Au–S bond. In vitro toxicity assessments illustrated that Apt-AuNSs have low cytotoxicity and suitable for biological applications. Furthermore, the accumulation of Apt-AuNSs in HeLa cells was observed via TEM image. The targeted photothermal therapy in vitro and apoptosis assay results showed excellent anticancer effect. These results suggest that the targeted Apt-AuNSs exhibit great potential in selective photothermal therapy of cancer.