Mohsen Kalantari - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Mojtaba Salouti - Biology Research Center, Zanjan Branch, Islamic Azad University, Zanjan, Iran.
Kazem Parivar - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Mehrdad Hamidi - Zanjan Pharmaceutical Nanotechnology Research Center, Zanjan University of Medical Sciences, Zanjan, Iran.
Saeed Emadi - Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran.

Treatment methods for breast cancer are not specific and each one has its own drawbacks. For this reason, scientists are seeking ways in which specifically affect cancer cells. Photothermal therapy is a method that uses near-infrared (NIR) laser energy to create sufficient heat to destroy cancer cells. In this study, the photothermal effect of gold nanorods (GNRs) was investigated for breast cancer treatment in vitro and in vivo. GNRs with the peak absorption of ۸۰۸ nm were synthesized and conjugated with Herceptin (anti-HER۲). After confirming the characteristics of the prepared conjugate, the therapeutic effect of the new agent was studied on SK-BR-۳ cell line and BALB/c mouse model bearing breast tumor using the NIR laser. The cytotoxicity assay showed the biocompatibility of PEGylated GNRs-HER conjugate. Through the in vitro photothermal study, significant cell death was observed in breast cancer cells incubated with the conjugate along with the laser irradiation. Afterward, the biodistribution of the conjugate in the mouse model with breast tumor showed the considerable localization of new agent in breast tumor in comparison with other organs ۲۴ h postinjection. The animal study showed a significant decrease in tumor growth rate as well as the increased lifespan of treated mice with breast tumor in comparison with the control groups.

Breast cancer, Gold nanorods, HER۲ receptor, Herceptin, Photothermal therapy