Investigation of Sub-100 nm Gold Nanoparticles for Laser-Induced Thermotherapy of Cancer

Abstract

Specialized gold nanostructures are of interest for the development of alternative treatment methods in medicine. Photothermal therapy combined with gene therapy that supports hyperthermia is proposed as a novel multimodal treatment method for prostate cancer. In this work, photothermal therapy using small (<100 nm) gold nanoparticles and near-infrared (NIR) laser irradiation combined with gene therapy targeting heat shock protein (HSP) 27 was investigated. A series of nanoparticles: nanoshells, nanorods, core-corona nanoparticles and hollow nanoshells, were synthesized and examined to compare their properties and suitability as photothermal agents. In vitro cellular uptake studies of the nanoparticles into prostate cancer cell lines were performed using light scattering microscopy to provide three-dimensional (3D) imaging. Small gold nanoshells (40 nm) displayed the greatest cellular uptake of the nanoparticles studied and were used in photothermal studies. Photothermal treatment of the cancer cell lines with laser irradiation at 800 nm at 4 W on a spot size of 4 mm (FWHM) for 6 or 10 min resulted in an increase in temperature of ~12 °C and decrease in cell viability of up to 70%. However, in vitro studies combining photothermal therapy with gene therapy targeting HSP27 did not result in additional sensitization of the prostate cancer cells to hyperthermia.

Photosensitizer effects of MWCNTs-COOH particles on CT26 fibroblastic cells exposed to laser irradiation

“…In the hyperthermia therapy, the tumoral cells underwent a temperature range of about 45-42 C or a higher temperature for a few minutes. It makes tumoral cells sensitive against main treatments such as radiotherapy and chemotherapy, and causes the death of a percentage of these cells by heat [8][9][10]. Hyperthermia prevents the repairing DNA damages of cells induce by radiation which is probably due to its effect on cell proteins [11].…”

“…Latter method has more treatment efficacy than the other two methods, because of the more useful surface plasmon resonance (SPR) oscillations of nanoparticles to dye molecules and natural chromophores. Therefore, in nanomaterial-based photothermal method, less power and energy is needed to increase a certain amount of temperature than conventional PTT, and the fundamental characteristics of nanoparticles is optical stability [9,10,12,14,15]. In PPT, the plasmonic nanoparticles are delivered to the tumor, and these particles are exposed to laser light.…”

Nanomaterials for biomedical applications

“…NPs are currently being used for hyperthermia treatment (Maier-Hauff et al 2011), and photodynamic therapy (Robertson et al 2009). For example, AuroShell is a nanoproduct that kills cells at the target tumor site by emitting heat upon absorption of near-infrared (NIR) light (Leung et al 2013).…”

Contribución a las tecnologías hipertérmicas mediadas por nanopartículas para terapias anticancerígenas

“…células. Esta es una técnica muy interesante pero la potencia de radiación que se utiliza de 4W es muy alta y produce quemaduras [16].…”

“…forma y composición de superficie[16]. Después de la absorción de la luz, los electrones de superficie se fotoexcitan y el haz de electrones resultante calentado se disipa en unos pocos picosegundos al medio circundante[3], donde el daño fototérmico resultante en los tejidos biológicos incluye ruptura de la membrana celular, desnaturalización de proteínas, deterioro de la síntesis de ADN y de ARN y apoptosis[9],[17].…”