title: Enhanced single strand breaks of supercoiled DNA in a matrix of gold nanotubes under X-ray irradiation.
abstract: Single-strand-breaks (SSBs) of supercoiled DNA (scDNA) molecules were used to probe the enhancement of X-ray radiation effect on scDNA mixed with gold nanotubes (AuNTs) in water. The amounts of measured enhancements using SSBs were significantly lower than the expected increase in energy deposition in water by AuNTs under hard X-ray irradiation. Three factors were identified to negatively affect the enhancement: (1) Attenuation of kinetic energies carried by electrons escaped from AuNTs, (2) Scavenging of OH radicals (˙OH) by the surface of bare AuNTs, and (3) Steric effect due to soluble scDNA molecules away from the surface of AuNTs. Benefits and limits of using gold nanomaterials as radiation enhancers and contrast agents are discussed.
authors.affiliation: Department of Chemistry, University of California, Davis, CA 95616, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Carter
authors.forename: Neal N
authors.initials: NN
authors.lastname: Cheng
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Qu
authors.forename: George D
authors.initials: GD
authors.lastname: Suarez
authors.forename: Ting
authors.initials: T
authors.lastname: Guo
mesh_terms: D003287:Contrast Media / Q000009:adverse effects / Q000737:chemistry*; D053904:DNA Breaks, Single-Stranded; D004278:DNA, Superhelical / Q000737:chemistry*; D006046:Gold / Q000009:adverse effects / Q000737:chemistry*; D043942:Nanotubes / Q000009:adverse effects / Q000737:chemistry*; D014965:X-Rays
chemical_list: D003287:Contrast Media; D004278:DNA, Superhelical; D006046:Gold