Measurements of nanoparticle-enhanced heating from 1 MHz ultrasound in solution and in mice bearing CT26 colon tumors. (December 2016) - Beik, Jaber
Abstract: Hyperthermia is considered as a new approach for cancer therapy. Non-selectivity of tissue heating in conventional hyperthermia methods results in collateral damages to healthy tissues and this is the greatest obstacle against hyperthermia in clinic. Herein, to promote the efficiency of conventional hyperthermia methods, nanoparticle-enhanced heating from 1 MHz ultrasound was investigated in vitro and in vivo . The experiments were conducted on two mediums; (1) various colloidal nano-solutions ( in vitro section) and (2) CT26 mouse colon carcinoma tumor loaded by various nanoparticles ( in vivo section). Experiments in this study were designed to evaluate and compare the sonosensitizing potentials of gold nanoparticles (AuNPs), iron oxide nanoparticles (IONPs), and nano-graphene oxide (NGO) in enhancement of ultrasound-induced heat generation. The temperature profile of the solutions and the animal tumors containing nanoparticles were recorded during sonication. An increased heating rate during sonication was observed for both in vitro and in vivo mediums when the nanoparticles were present. Our in vitro experiments revealed that percentages of increases in temperature elevation rates were 12.5%, 20.4%, and 37.5% for IONPs, NGO, and AuNPs, respectively. Compared to the nanoparticles-free tumors, direct injection of AuNPs, NGO and IONPs into the tumors and subsequent sonication for 10 min caused an increased temperature elevation rate of 37.5%, 24.1% and 16.1%, respectively. AuNPs, IONPs and NGO are proposed as ultrasound responsive nanomaterials with the potential of focusing the energy of acoustic waves on the tumor and inducing localized hyperthermia. Graphical abstract: Nanoparticles are concentrated inside the tumor and may absorb the energy originated from ultrasound generator to enhance the effects of hyperthermia. IONPs : iron oxide nanoparticles. AuNPs : gold nanoparticles. NGO : nano-graphene oxide. Highlights: The sonosensitizing effects of nano-graphene oxide, gold and iron oxide nanoparticles were investigated in vitro and in vivo . Nano-graphene oxide, gold and iron oxide nanoparticles had synergistic impact on ultrasound induced heat generation. Nano-graphene oxide was proposed as an ultrasound responsive nanostructure for the first time. The physical mechanism of nanoparticle-enhanced heating from ultrasound is discussed in-depth.