In vivo photothermal tumour ablation using gold nanorods

Less invasive and more effective cancer treatments have been the aim of research in recent decades, e.g. photothermal tumour ablation using gold nanorods. In this study we investigate the cell death pathways activated, and confirm the possibility of CTAB-coated nanoparticle use in vivo. Nanorods were synthesized by the seeding method; some of them were centrifuged and washed to eliminate soluble CTAB. The MTT cytotoxicity test was performed to evaluate cytotoxicity, and the particles' viability after their synthesis was assessed. Once it had been observed that centrifuged and washed nanorods are harmless, and that nanoparticles must be used within 48 h after their synthesis, in vivo hyperthermic treatment was performed.After irradiation, a tumour biopsy was subjected to a chemiluminescence assay to evaluate membrane lipoperoxidation, and to a TRAP assay to evaluate total antioxidant capacity. There was a 47 ºC rise in temperature observed at the tumour site. Animals irradiated with a laser (with or without nanorods) showed similar membrane lipoperoxidation, more intense than in control animals. The antioxidant capacity of experimental animal tumours was elevated. Our results indicate that necrosis is possibly the cell death pathway activated in this case, and that nanorod treatment is worthwhile.