| ObjectiveNanotechnology is at the end of the 20th century,80's,early 90's developed and emerging cross-cutting disciplines,is causing global major changes in the aspects of science and technology,industry and agriculture.Nano-materials have many excellent and unique physical and chemical properties (such as caused by the nanometer scale by the scale effect,quantum effect,surface effect, as well as a great interface effect,etc.),therefore,they show attractive applications in industry,construction,bio-medical,daily necessities and environmental protection industry. However,science is a double-edged sword,in the well-being of mankind,and may bring harm to human beings,nanotechnology is no exception.After the materials entering into the nanometer scale,often show significant different characteristics of physical and chemical from conventional cognitive.The nano-particles can't been seen by naked eyes,and non-traditional microscopes can observe,so security performance testing has become a difficult work.The method of traditional toxicological testing and risk assessment of chemicals is not fully applicable,so the biological safety evaluation has become an important issue,nano materials and products need to develop the production of safety standards.How to manage nanotechnology to benefit humanity rather than harm is not only the challenges facing the scientific community as well as the development of nanotechnology Governments have to face.In this study,by virtue of the genetic toxicology of the most widely used to detect gene mutations in the Ames test of the experimental platform,on the current most widely used three types of nano-materials(carbon nanotubes,nano-titanium dioxide,nano-ZnO) to carry out safety studies,in order to Prediction of the genetic material of these three potential hazards and to provide experimental evidence of carcinogenicity. Method1 Nutrient medium and panelUsed in this study are the standard medium and flat-panel production Ames test requirements2 Activation systemLiver S-9 is the use of sodium phenobarbital and P-2-induced Chennai jointly prepared flavonoids.S-9 mixture of the preparation,use and preservation is to operate in accordance with the Ames test.3.Appreciation of stain genetic determinantIn accordance with the Ames test methods identified are as follows:(1) demand histidine test;(2) Appreciation of lipopolysaccharide barrier defects(rfa mutation);(3) Appreciation of UV sensitivity(uvrB repair defects type of appreciation);4) anti-ampicillin (PKM101) test(R factor,the loss of appreciation of strains);(5),tetracycline(PAQI) appreciation of resistance;(6) spontaneous return variables(his +) of the determination;(7) the sensitivity of identification of the mutation-positive agents.After the genetic trait tests, carried out the safety of nano-materials research.4 Design of dosageBecause carbon nanotubes are not soluble in water and DMSO,so we have adopted the form of suspension design of the five dose group;ZnO nano-titanium dioxide and dissolved in ultrasound is designed under the condition of five dose groups,a separate natural to change the control group,solvent control group(water) and positive control group.5 testing methodIn the flat-plate incorporation test of Salmonella typhiurium,the average numberof spontaneous revertants of TA97,TA98,TA100,TA102 under 5 concentrations was calculated after incubation at 37℃for 48 hours.ResultsMulti-walled carbon nanotube bacterial reverse mutation test(Ames),whatever each dose group has liver S-9 or not,the number of induced revertants of TA97,TA102 is spontaneous revertants 2 times or more than 2 times,a dose-response relationship.ZnO nano-titanium dioxide and bacterial reverse mutation test(Ames),each dose group has liver S-9 or not,the number of induced revertants of TA97,TA102,TA98,TA100 is spontaneous revertants 2 times.ConclutionsMulti-walled carbon nanotube bacterial reverse mutation test in the test dose range shift and cross-linking characteristics of the direct mutagenesis.nano-titanium dioxide and bacterial reverse mutation test has no potential mutagenicity.
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