[Hyperthermia on colorectal cancer: gold nanoshells-mediated photothermal therapy]

Colon cancer or colorectal cancer is one of the most common malignant neoplasms in the world, characterized by uncontrolled cell growth on the colon mucosa. Treatment approaches depend primarily on the characteristics of the tumor´s localization, size, metastasis, and the health status of the patient. Nanomedicine shows itself as a novelty strategy to overcome the limitations of the therapies used in the clinic due to the disregard of the mechanisms associated with multidrug resistance because of the nanometric size of the particles utilized. Gold nanoshells are spheric structures of an approximate size of 30 nm, coated with an ultrathin gold layer that can absorb near-infrared light and convert it to thermal energy to produce hyperthermia on in vivo models of cancer tumors. Nanoparticles-assisted hyperthermia consists of control, direct, and specific heating against the tumor cells by nanoparticle irradiation with an external power source capable of increasing temperature to 39°C - 45°C without damaging surrounding healthy tissue. Compared with other nanomaterials, gold nanoshells show high biocompatibility and low cytotoxicity, which is why adjuvant chemotherapy and hyperthermia on gold nanoshells is a novel and promising approach for the treatment of colorectal cancer.