Glutathione-Capped Hollow Silver Nanoparticles: Optimization of Surface Plasmon Resonance, Photothermal Effect, and In Vitro and In Vivo Biocompatibility

Hollow metallic nanoparticles (HNPs) serve as excellent agents for biomedical applications because they possess surface plasmon resonance (SPR) and drug-loading capacity. These HNPs offer a high surface area for drug loading and show superior antitumour activity compared to their spherical counterparts. However, the precursors used to synthesize these HNPs, particularly hollow gold nanoparticles (HAuNPs), are expensive and highly toxic. Therefore, this article proposes an alternative class of nanoparticles─hollow silver nanoparticles (HAgNPs)─that employ nontoxic and inexpensive precursors. For the first time, this article investigates several parameters involved in the synthesis to obtain uniform HAgNPs, including the effect of the stabilizer, the concentration of the reducing agent, and the reaction temperature. This article further demonstrates the photothermally induced cytotoxicity of HAgNPs in cancer cells with a 532 nm Nd:YAG 300 mW continuous-wave (CW) laser. Moreover, this article demonstrates the biocompatibility of these HAgNPs by employing in vivo and ex vivo models. Finally, we propose future studies exploring the in vivo antitumor activity of these nanoparticles to establish their role in tumor drug delivery.