Biological Enhancement of X-Ray Effects

Au@TiO2 nanocomposites synthesized by X-ray radiolysis as potential radiosensitizers

“…Hainfeld et al were the first to report an animal study of Au nanoparticle radiosensitization. They observed a 86% increase in survival rate compared to 20% with X-rays alone when using Au nanoparticles with a particle size of 1.9 nm [121].…”

“…Nanomaterials bind to cells in order to cause enhanced damage under X-ray irradiation, and the damage can be further amplified [19]. Cells components such as mitochondria and nuclear DNA can be damaged by electrons emitted from nanomaterials or by the action of ROS that nanomaterials generate when irradiated with X-rays [121]. One hypothesis is that the mechanisms of physical and chemical enhancement are combined to amplify cell damage.…”

Enhanced Single-Strand Breaks of a Nucleic Acid by Gold Nanoparticles under X-ray Irradiation

“…The interactions of DNA and RNA with many nanomaterials such as gold nanoparticles (AuNPs) have been studied in the development of nanotechnology. ,− AuNPs have been found to influence chemical and biological reactions, especially when the whole system is irradiated with X-rays. ,,,− The interactions can be divided into physical and chemical enhancement to the effect of irradiation of the target such as DNA or RNA in the presence of AuNPs. ,, It was suggested that LEEs may be responsible for the observed single-strand breaks (SSBs) when dry DNA is coated on gold surfaces under X-ray irradiation. , Such a process, as well as DNA on inert surfaces of nanoparticles, belongs to the category of physical enhancement. Catalytic reactions, on the contrary, belong to the category of chemical enhancement and have been proposed for DNA in water in the presence of AuNPs. ,,− If AuNPs can indeed help catalytically convert the dominating nucleobase damage, as the main product of •OH reacting with DNA in water, to sugar radicals and eventually to SSBs, similar to other radical conversion processes reported in the literature, , then DNA near the surface of AuNPs can be more useful as the building blocks used in nanotechnology and medicine.…”