Nanochemistry and biotechnology
“Green” synthesis of silver nanoparticles using the extracts of “hairy” root cultures of medicinal plants 

Matvieieva N.A.1, Shakhovsky A.M.1, Ratushnyak Ya.I.1,  Kobylinska N.G.2, Khainakova O.3, Klymchuk D.O. 4, Duplij V.P.1, Kuchuk M.V. 1

1 Institute of Cell Biology and Genetic Engineering, National Academy of Sciences of Ukraine, 148 Zabolotnogo str, Kyiv-03143, Ukraine
2Taras Shevchenko State University, Volodymyrska str 64, Kyiv, 01601, Ukraine
3University of Oviedo-CINN, Av. Julian Claveria 8, 33006 Oviedo, Spain
4M.G. Kholodny Institute of Botany NAS of Ukraine, 2, Tereshchenkivska st.,  Kyiv- 01004, Ukraine

E-mail: duplijv@icbge.org.ua 

Nanotechnologies aimed in the synthesis of metal nanoparticles are one of the favorable trends in the science. There are some methods proposed for nanoparticles production – physical, chemical, and also the methods used biomaterials. The last one has some advantages due to the exception of hazardous chemicals using and high energy requirements. It is a low cost and environmentally friendly technology. So called “green” synthesis of metal nanoparticles is a good alternative to chemical synthetic and physical methods application. Various plant species were used to study the process of silver nanoparticles (AgNPs) formation.  AgNPs obtained due to the “green” synthesis demonstrated high level of antimicrobial activity and can be used in medicine. At the same time comparison of the effectiveness of AgNps synthesis after the contact of AgNO3 solution and plant extracts is of great interest because of the great differences in the methabolism, accumulation of biologically active compounds, Rh potential, antioxidant and reducing activity. “Hairy” root cultures characterized by the high reducing activity and increased synthesis of such compounds as sugars, polyphenols, flavonoids also can be used for the “green” synthesis of metal nanoparticles. 
“Hairy” root cultures of Artemisia vulgaris, A. tilesii, A. annua, Cichorium intybus, Bidens pilosa medicinal plants were initiated after the genetic transformation with soil phytopathogenic bacteria Agrobacterium rhisogenes A4. These roots were cultivated in in vitro conditions, lyophilized and used as the material for extract obtaining (fig.1).
Both water and ethanolic extracts have demonstrated the possibility for synthesis of AgNPs. After the adding of the extracts to AgNO3 solution and heating in a water bath (+80°C,1 h) the color transformation was observed.  

Fig. – “Hairy” root culture (A) used for obtaining of the silver nanoparticles (B)

The UV–Vis  spectra peaks revealed in 430-475 nm, 430-440 nm, 430-480 nm, 430-440 nm, and 430-450 nm intervals in the case of A. tilesii , B. pilosa, A. vulgaris, A. annua, and C. intybus extracts respectively. The synthesis process was precisely controlled and AgNPs of average size 10 - 100 nm were synthesized with good yield and monodispersity. Nanoparticles obtained with plant extracts verified also by their forms (spherical, oval). We found the extract effect of AgNPs to be size and dose-dependent as determined is in the case various “hairy” root cultures. So, the results of our study confirmed that “hairy” root cultures of medicinal plants can be used for the “green” synthesis of silver nanoparticles.