Cancer Cell Damage at Laser-Induced Plasmon-Resonant Photothermal Treatment of Transplanted Liver Tumor

Here, we report the morphological investigation of gold nanorod (GNR)-mediated photothermal changes in transplanted liver tumors PC-1 and discuss photothermal induced therapeutic pathways of cancer cell damage. Thirty male outbred albino rats with transplanted liver cancer PC-1 are used in the experiment. The GNRs (length 41 ± 8 nm, diameter 10.2 ± 2 nm) suspended in saline with gold concentration of 400 μg/ml are injected intratumorally an hour before laser irradiation. The tumor is irradiated during 15 min with the near infrared (NIR) 808-nm laser at a power density of 2.3 W/cm 2 . Temperature control of the tumor heating is provided with IR imager. The withdrawal of the animal from the experiment is performed 24 h after the laser exposure. We use the standard histological and immunohistochemical staining with antibodies for Ki-67, p53, FAS receptor, FAS ligand, and EGFR for morphological study of transplanted tumors. After plasmonic photothermal therapy (PPT), the pronounced necrotic changes in the tumor tissue are revealed. The decreasing expression of the proliferation marker Ki-67 and the increasing expression of apoptosis markers (p53, FAS receptor, and FAS ligand) are observed after PPT.