Photothermal therapy in a murine colon cancer model using near-infrared absorbing gold nanorods

Abstract

Abstract. The photothermal ablation of solid tumors using exogenous, near-infrared ͑NIR͒-absorbing nanoparticles has been previously investigated using various preclinical models and is currently being evaluated in the clinic. Here, we evaluate the circulation kinetics, preliminary toxicity, and efficacy of photothermal ablation of solid tumors using gold nanorods systemically delivered and passively accumulated in a murine subcutaneous colon cancer model. Tumored animals were infused with nanorods followed by the percutaneous illumination of the tumor with an 808-nm laser. Control groups consisted of laser-only, nanorod-only, and untreated tumored animals. The survival of the treated and control groups were monitored for 60 days post-treatment. The survival of the photothermally treated group was statistically longer than the control groups, with approximately 44% tumor free through the evaluation period. Histopathology of the major organs of animals infused with nanorods did not indicate any significant toxicity at 60 days post-treatment. Particle biodistribution was evaluated by elemental analysis of the major organs of untumored mice at 1, 7, and 30 days after infusion with nanorods. Elemental analysis indicates nanorod clearance from the blood and retention by the reticuloendothelial system. This study indicates that gold nanorods are promising agents for photothermal ablation of solid tumors.

Optically stimulated heating using Nd3+ doped NaYF4 colloidal near infrared nanophosphors

“…Further improvement by reducing the excitation light intensity may be achieved, since only 6 • C temperature rise is sufficient for hyperthermia therapy. Thus, the intensities could be lower than 15-25 mW (47-80 W/cm 2 ), which currently is only an order of magnitude higher than for gold nanostructures [11,14]. Yet further highly promising optimization may be carried out by application of oxide NPs instead of fluorides to significantly improve the nonradiative rates and increase heat generation efficiency.…”

“…The spatial localization is usually achieved by biofunctionalization of the nanoparticles (NPs) surface with antigens [7,9,10]. Biofunctionalized gold nanostructures (nanorods [11], nanocubes [12], nanocages [13,14], nanoshells [15] as well as hybrid Au-Fe3O4 [16]) or graphene [17] have been successfully applied as nanoheaters in many in-vitro studies and allowed to diminish most of the drawbacks of the original method. However, cetyltrimethylammonium bromide (CTAB) used as gold nanostructures surfactant and stabilizer, demonstrated inherent toxicity.…”

The Combination of Laser Therapy and Metal Nanoparticles in Cancer Treatment Originated From Epithelial Tissues: A Literature Review

“…In all in vitro and animal studies, the result of combined use of nanoparticle and laser for therapeutic purposes was the death of cancerous cells and enhancement of tumour contrast for imaging intentions. 3,7,25,38,48 The type of Laser applied in most of the investigations was NIR with wavelength spectra of 785 nm up to 1046 nm, 4,7,10,15,21,39,40,56,59 with 808 nm wavelength used more frequently. 10,20,25,29,34,41,49,62,72 As mentioned earlier, the 808 nm wavelength was the most effective in studies aiming at photothermal destruction of cancer cells.…”

“…Transformation of nanoparticles can be done in a systemic way (through intravenous injection). 9,10 Many studies have been done in this field.…”

“…Thermal therapy procures a fast recovery, shorter hospital stay, less complications and is easy to perform. 10 There are a variety of nanoparticles, and each has its own unique properties and applications such as nanorings, nanoshells, nanorods, nanopores and nanowires, etc. Depending on the peak absorption of nanoparticles, different lasers are used.…”