## 4 Results  
To ascertain the composition and structure of the samples, they were subjected to physicochemical analysis. Dioxidine was modified at the first stage. The drug substance particles were micronized, and silver or copper nanoparticles were incorporated into the dioxidine particles during cryogenic synthesis procedure. FTIR spectra of the systems obtained were similar to cryomodified form of dioxidine obtained via cryogenic freeze drying method [16; 21; 22]. The band corresponding to the vibrations of quinoxaline ring was at 1510 cm\({}^{-1}\); the bands corresponding to the vibrations of the C-H bonds of the benzene rings were registered at 975, 1130, and 1160 cm\({}^{-1}\); the band of C-O-H vibrations was observed at 1288 cm\({}^{-1}\). X-ray diffraction patterns and the set of interplanar spacings (d, A) and their intensities (I\({}_{\text{re}}\), %) corresponded to the cryomodified form of dioxidine [21; 22] (d, A, I\({}_{\text{rel}}\), %: 8.740, 100.0; 8.026, 94.2; 6.899, 57.8; 6.288, 50.9; 5.978, 43.4; 3.358, 99.3; 3.304, 67.6). The absence of peaks corresponding to silver or copper in the X-ray diffraction of patterns was due to low metal content and the nanoscale size of their particles in each sample. The \({}^{1}\)HNMR spectra of the formed hybrid systems (in D\({}_{2}\)O) \(\delta\): 4.94-5.22 (m, 4H, 2\({}^{\circ}\)CH2), 7.85-8.05 (m, 2H, H Ar), and 8.37-8.52 (m, 2H, H Ar) were corresponded to dioxidine. The UV-visible spectra of aqueous solutions of Ag/dioxidine and Cu/dioxidine composites also were corresponded to dioxidine. An intense absorption band at 250 nm, attributed to the \(\pi\rightarrow\pi^{\ast}\) electron transition of the carbon atoms of the aromatic system, was observed in UV spectra, along with a band at 375 nm characterized by low intensity and attributed to the n \(\rightarrow\pi^{\ast}\) transition. The absence of absorbance bands corresponding to the surface plasmonic resonance (SPR) of silver or copper nanoparticles was due to the low content of silver or copper nanoparticles in each sample. According to the TEM data, obtained Ag/dioxidine and Cu/dioxidine nanocomposites (Figure 1) were composed of organic particles (50-350 nm) containing nanoscale particles of silver (2-30 nm) or copper (1-10 nm). The specific surface of the Ag/dioxidine composites was 31 m\({}^{2}\)/g (average particle size, 130 nm), and the specific surface of the Cu/dioxidine composite was 24 m\({}^{2}\)/g (average particle size, 166 nm). The specific surface of the Ag/gentamicin sulfate was 32 m\({}^{2}\)/g (average particle size, 144 nm), and the specific surface of the Cu/gentamicin sulfate was 31 m\({}^{2}\)/g (average particle size, 149 nm). These data were in good agreement with the TEM results. The FTIR spectra of hybrid composites of gentamicin sulfate with silver and copper nanoparticles were corresponded to the FTIR spectrum of gentamicin sulfate (bands of the NH\({}_{2}\)-, NH\({}_{3}\)- groups at 1520, 1625, and 3280 cm\({}^{-1}\); HSO\({}_{4}\)\({}^{-}\) and C-O at 1059 cm\({}^{-1}\); and SO\({}_{2}\) at 607 cm\({}^{-1}\) were characteristic for gentamicin sulfate [23]). The \({}^{1}\)H NMR spectra of hybrid composites of gentamicin sulfate with silver and copper nanoparticles, as well as the compounds released from the composite nanofforms incorporated in the biopolymer matrices, were corresponded to literature data for gentamicin sulfate [24; 25]. According to TEM micrographs, the Ag/gentamicin sulfate and Cu/gentamicin sulfate nanocomposites consisted of organic particles (50-350 nm in size), inside of which the nanosized particles were incorporated, and their electron diffractograms were corresponded to silver or copper. The size of metal nanoparticles in the obtained systems was 2-30 nm for silver and 1-9 nm for copper. The hybrid nanocomposites \"Ag/antibacterial drug\" or \"Cu/antibacterial drug\" were loaded into the cryogenically structured biopolymer wide-pore spongy matrices based on gelatin, chitosan, or Ca-alginate.