Nanobiotechnology for health-care 

Nanocomposites with ornidazole – antibacterial and antiadhesive agents against gram‑positive and gram‑negative bacteria
Lupatsii M.1, Furtat I.1, Murlanova T.1, Vakuliuk P.1, Golub A.1 
1National University of Kyiv-Mohyla Academy, 2 Skovoroda Str., Kyiv, 04070, Ukraine
Email: marijka11@ukr.net; furtat@ukma.edu.ua
In view of growing rates of mortality and morbidity caused by resistant to antibiotics bacteria, new approaches should be invented to inhibit the spread and progression of infectious diseases. One of such approaches is the use of nanocomposite materials with active compounds, which are characterized as antibacterial and antiadhesive agents. 
The object of our research was nanocomposite synthesized on the basis of disperse pyrogenic silica with 1-chloro-3-(2-methyl-5-nitro-1-H-imidazol-1-yl)- propan-2-ol (ornidazole) from aqueous and alcoholic solutions. To study the effect of nanocomposites with ornidazole the standardized suspensions of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 cells with the concentration of 0,5 McFarland units were used. According to the Yould method antimicrobial efficacy of studied nanocomposites was estimated after the effect of nanocomposites on bacterial cells during 2 and 24 hours. Adhesive properties of bacterial cells were estimated due to Brillis method. 
It was shown that nanocomposites with ornidazole were more effective during 24 hour contact with bacterial cells. The number of bacterial cells reduced up to 99,999 % in the case of S. aureus and up to 100 % in case of gram-negative bacteria. It’s important to notice that pure ornidazole without introduction to nanocomposite wasn’t active against any of the tested bacterial cultures. Study of bacterial adhesive properties was carried out using erythrocytes of different blood types, it was estimated that the adhesiveness of bacteria and the antiadhesive effect of nanocomposites varied depending on the blood type. For example, adhesion of staphylococcal cells to erythrocytes of OO+ blood type during 2 hour contact was inhibited for 84 %, while to erythrocytes of AB+ blood type – only for 4 %. Nanocomposites with 4 % of ornidazole synthesized from alcoholic solution were more effective against S. aureus during 24-hour contact, while nanocomposites with 2 % of ornidazole – against E. coli and P. aeruginosa 
Therefore, our research shows that nanocomposites with ornidazole are characterized as antimicrobial and antiadhesive agents against gram-positive and gram-negative bacteria, which proves that this type of nanocomposites can be prospective in order to inhibit the spread and development of infectious diseases.