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Abstract:
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Cancer is one of the most notorious diseases affecting the human population today with very few effective treatments . Due to the disparate nature of cancers , it is difficult to obtain a treatment that can cure cancer . Thus , there is a large influx of research towards cancer therapies , leading to one of the discovery that cancer cells (tumors ) have a low thermotolerance in comparison to normal cells . If the temperature of the cancer cells is increased into the hyperthermia range ( ~45°C ) thermal damage occurs , causing cell death by protein denaturation and membrane disruption . A recent development in this field has been in the photothermal treatment of tumors , which is starting to utilize plasmonic particles to enhance the specificity of the treatment . The plasmonic nanoparticles , specifically gold , can reach the tumor site using passive targeting and when irradiated with a tuned laser will emit heat localized to a small region around the nanoparticle killing the surrounding cancer cells . This process has been shown to reduce tumor size in vivo with gold nanoshells and gold nanorods .
However , it has not been shown which particle is better at delivering the heat to the tumor site . Therefore in this study , it will be shown which particle generates the most heat . Solutions of tissue simulating phantom and different concentrations of nanoparticles were irradiated with a laser to measure the increase in temperature . Additionally , simulations were performed using Mie Theory for nanoshells and the Discrete Dipole Approximation for nanorods . Based on the physical parameters of the nanoshells and nanorods used in this experiment , the adjusted absorption cross -section was determined . It was found that nanoshells generated the most amount of heat on a per particle basis , and that it was necessary to have a nanorod concentration of 5 .5 times the concentration of nanoshells to generate the same amount of heat as nanoshells . These results were confirmed using Monte Carlo and Finite Difference Modeling of the nanoparticle heating experiments . However , the choice of nanoparticle still depends on the application and the targeting efficiency in vivo . |