title: Gold nanoparticles enhance the radiation therapy of a murine squamous cell carcinoma.
abstract: The purpose of this study is to test the hypothesis that gold nanoparticle (AuNP, nanogold)-enhanced radiation therapy (nanogold radiation therapy, NRT) is efficacious when treating the radiation resistant and highly aggressive mouse head and neck squamous cell carcinoma model, SCCVII, and to identify parameters influencing the efficacy of NRT. Subcutaneous (sc) SCCVII leg tumors in mice were irradiated with x-rays at the Brookhaven National Laboratory (BNL) National Synchrotron Light Source (NSLS) with and without prior intravenous (iv) administration of AuNPs. Variables studied included radiation dose, beam energy, temporal fractionation and hyperthermia. AuNP-mediated NRT was shown to be effective for the sc SCCVII model. AuNPs were more effective at 42 Gy than at 30 Gy (both at 68 keV median beam energy) compared to controls without gold. Similarly, at 157 keV median beam energy, 50.6 Gy NRT was more effective than 44 Gy NRT. At the same radiation dose ( approximately 42 Gy), 68 keV was more effective than 157 keV. Hyperthermia and radiation therapy (RT) were synergistic and AuNPs enhanced this synergy, thereby further reducing TCD50 s (tumor control dose 50%) and increasing long-term survivals. It is concluded that gold nanoparticles enhance the radiation therapy of a radioresistant mouse squamous cell carcinoma. The data show that radiation dose, energy and hyperthermia influence efficacy and better define the potential utility of gold nanoparticles for cancer x-ray therapy.
authors.affiliation: Nanoprobes, Inc., Yaphank, NY 11980, USA.
authors.forename: James F
authors.initials: JF
authors.lastname: Hainfeld
authors.forename: F Avraham
authors.initials: FA
authors.lastname: Dilmanian
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zhong
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Slatkin
authors.forename: John A
authors.initials: JA
authors.lastname: Kalef-Ezra
authors.forename: Henry M
authors.initials: HM
authors.lastname: Smilowitz
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D006046:Gold / Q000737:chemistry*; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006979:Hyperthermia, Induced; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D015233:Models, Statistical; D036103:Nanotechnology / Q000379:methods*; D009374:Neoplasms, Experimental / Q000532:radiotherapy*; D011878:Radiotherapy / Q000379:methods; D016896:Treatment Outcome; D014965:X-Rays
chemical_list: D006046:Gold