Nanobiotechnology for health-care 

Green synthesized silver nanoparticles as potential safety disinfectants  
Dybkova K.M.1,2, Rieznichenko L.S.2, Tiutiun S.M.3, Zhovnir O.M.3, Gruzina T.G.2, Dybkova S.M.2
1 Biology and Medicine Institute Science Educational Center of Taras Shevchenko National University of Kyiv, Glushkova Av., 2, Kyiv-02000, Ukraine. 
E-mail: kateryna.dybkova@gmail.com
2 Department of Colloidal Technologies of Natural Systems, F.D. Ovcharenko Institute of Biocolloidal Chemistry NAS of Ukraine, Vernadskogo Av., 42, Kyiv-03142, Ukraine.
3 Laboratory of Anaerobic Infections, Institute of Veterinary Medicine NAAS of Ukraine, Donetska Str., 30, Kyiv-03151, Ukraine.

Multiple biological threats, including the current situation with the coronavirus-provoked pandemic, determine the increasing demand in the effective and safe disinfectants. Such a problem is actual both for medicine and veterinary. Traditional alcohol- and chlorine-based disinfectants have some disadvantages and limitations especially for veterinary use. As per the modern studies, nanomaterials particularly silver nanoparticles can serve as novel high effective and safe disinfectants with wide spectra of antimicrobial, antifungal and antiviral activity. The application of “green synthesis” methods among the different ways to obtain nanoparticles gives opportunity to receive cheaper nanomaterials possessed by higher biocompatibility and safety together with the basic requested properties.  
Silver nanoparticles (AgNPs) were synthesized in water medium by the reduction of the silver nitrate using tannin and mint extract as reducing agents.
Safety assessment of the synthesized nanoparticles was defined with the level of their cytotoxicity and genotoxicity using cell lines L929 and MDBK according to the Guidelines of the Ministry of Health of Ukraine "Assessment of the safety of nanopreparations". The genotoxicity of the synthesized AgNPs was assessed by the Comet assay in alkaline conditions; cytotoxicity was analyzed with the MTT-test and crystal violet staining method. Both types of the synthesized AgNPs were characterized as safe according to the studied parameters.  
Analysis of the disinfectant properties of the synthesized nanoparticles in the quantitative suspension test using Escherichia coli, Salmonella enteritidis and Salmonella dublin clinical isolates has shown total inhibition of the bacteria cells’ growth after 30 and 45 min exposition of the microbial suspensions with AgNPs.