Enhanced single strand breaks of supercoiled DNA in a matrix of gold nanotubes under X-ray irradiation

Average Physical Enhancement by Nanomaterials under X-ray Irradiation

“…30 In addition, when the concentration of small nanoparticles is high enough another enhancement mechanismAE (ε expt AE , generally a negative value) rather than the combination of PE and CE may dominate. Scavenging species at the surface of nanomaterials or the surface itself can both cause AE, 7 which reduces the enhancement by nanomaterials.…”

“…13−21 Special theoretical enhancement conditions have been proposed, although they are difficult to realize experimentally. 22−25 Generally speaking, large amounts (>1 wt % (wp) of Au in water or a similar medium) of large size nanomaterials have to be used to create measurable T1PE in water, 7,26 whereas as little as parts per million (ppm or 10 −4 wp) of small-sized nanomaterials may be enough to create measurable T2PE in water. 6 Theoretical studies have predicted high enhancement for T2PE (enhancement factor ε theo T2PE ) of over 200-fold around a single nanostructure.…”

X-ray triggered release of doxorubicin from nanoparticle drug carriers for cancer therapy

“…Given the amount of AuNPs in the cell (B30 wt%), the observed small amount of enhanced toxicity seems to suggest that these nanoparticles stayed in the cytoplasm because this amount of AuNPs in the cell would cause significant damage if only X-ray absorption enhancement is considered. 22,23 For treatment of breast cancer patients using radiotherapy of a standard 50 Gy total dose in 5-10 fractions, 24 the current NDC would generate a significantly increased toxicity of 165% to the tumor. The NDC designed here may therefore be used in the currently popular hypofractionated radiotherapy in which multiple fractions of 5-12 Gy per fraction are administered.…”

“…This shows that AuNPs are highly scavenging towards radicals, behaving similarly to DMSO, which is understandable because the gold surface is an effective reactive oxygen species (ROS) scavenger. 22,29 As shown above each DNA carries 9 DOX. When cleavage occurs, the DNA may be broken anywhere along the strand, releasing between 1 and 9 DOX.…”

An Example of X-ray Nanochemistry: SERS Investigation of Polymerization Enhanced by Nanostructures under X-ray Irradiation

“…Several examples of chemical enhancement have been demonstrated in the literature, which include enhanced yield of DNA cleavage and reactions to form fluorescent molecules. ,, Since polymerization may be initiated using various means including X-rays, it is natural to consider that nanomaterials may enhance such a process. It would be a significant scientific and technological advancement if a small dose of X-rays can trigger the growth of polymers, especially at remote and not easily accessible locations by light, or in an environment difficult to deliver large amounts of chemical initiators.…”