Facile preparation of albumin-stabilized gold nanostars for the targeted photothermal ablation of cancer cells

Abstract

Gold nanostars (AuNSs) have been extensively studied as photothermal conversion agents for cancer therapy due to their high photothermal conversion efficiency. Surface modification is required to improve their colloidal stability and biocompatibility for biomedical applications. Moreover, the targeting delivery of AuNSs into the tumor sites is an effective approach to improve their therapeutic efficiency. In this study, we report the use of folic acid–bovine serum albumin conjugate (BSA–FA) stabilized AuNSs (BSA–FA–AuNSs) as agents for the targeted photothermal ablation of cervical cancer cells (HeLa). In our approach, BSA–FA conjugate was first synthesized via an amidation reaction, which was further used as a stabilizer to coat the AuNSs for surface modification. The BSA–FA–AuNSs showed good dispersibility and colloidal stability in different media. The strong absorption properties in the near-infrared (NIR) region enabled the increasing temperature of AuNSs under laser irradiation. The BSA–FA–AuNSs not only had a very low cytotoxicity in the studied concentrations, but they also showed targeting specificity to FA receptors-overexpressed cancer cells, which was confirmed by studying the cellular uptake. In addition, the BSA–FA–AuNSs displayed a much better therapeutic efficiency to HeLa cells under the NIR laser irradiation when compared with BSA–AuNSs without FA modification. The BSA–FA–AuNSs should have a great potential as photothermal conversion agents for the receptor-mediated treatment of cancer cells.