Nanobiotechnology for health-care
 
Hybrid Hydrogels With Biologically Active Dyes and Their Antibacterial Efﬁcacy
O. Nadtoka1, P. Virych1, N. Kutsevol1, O. Krupka1, V. Smokal1,       V. Krysa2, S. Nadtoka1 
1Taras Shevchenko National University of Kyiv. Volodymyrska Street, 64/13, Kyiv-01601, Ukraine. 
2Ivano-Frankivsk National Medical University, Galytska str., Ivano-Frankivsk 76000, Ukraine.
E-mail: oksananadtoka@ukr.net

Hybrid cross-linked hydrogels Dextran-grafted-Polyacrylamide with different cross-linking density were synthesized as promising materials of a new generation for biomedical application [1]. Hybrid hydrogels have been synthesized by graft copolymerization reaction of Dextran and Acrylamide using N,N-methylene-bis-acrylamide as a cross-linker and cerium ammonium nitrate as an initiator. Methylene Blue (MB) and Brilliant Green (BG) were used as universal models of biologically active dyes. 
Sorption/desorption process of dyes into/out off hydrogels as an important factor for regulation of therapeutic concentrations of the active substances in bacteria medium were studied. It was obtained, that the release rate of absorbed MB and BG into hydrogel was higher for the sample with the lowest cross-linking density.
Antibacterial activity of hydrogel composites loaded with Methylene Blue as light-activated antimicrobial agent and irradiated with red light was tested in solid medium against wild strains S. aureus. 

Figure 1. The antimicrobial activity of dyes in hydrogels was activated with monochromatic light (390 nm, 460 nm and 530 nm). 
The high antimicrobial efficacy was registered. Thus, prepared hydrogel composites can be used as promising materials for wound dressings and photodynamic therapy.
1. O. Nadtoka, N. Kutsevol, V. Krysa, B. Krysa,  Mol. Cryst. Liq. Cryst.  672 (1) (2018) 1.