The influence of the chirality of chitosan ascorbate on the gelation kinetics and the properties of hybrid silicon-chitosan-containing glycerohydrogels were studied with a deep estimation of the stereospecificity of chitosan polysalts with l- and d-ascorbic acid diastereomers and their biological effects. It has been established that l- and d-diastereomerically enriched chitosan ascorbates are characterized by a positive Cotton effect and differ in the wavelength of the maximum of the dichroic band (250 and 240 nm), as well as in the values of its specific ellipticity (21.8 × 10⁵ and 39.2 × 10⁵ deg·mL·dm⁻¹·g⁻¹), the sign of specific optical rotation (+ and −), the type of dispersion curves (anomalous and smooth), as well as the condensed phase morphology (anisodiametric particles with optical anisotropy and confocal domains of spherical shape, respectively). In the biomimetic sol-gel synthesis of silicon-chitosan-containing glycerohydrogels using silicon tetraglycerolate as a precursor, it was found that chitosan d-ascorbate retarded gelation. Thin congruent plates obtained from the corresponding glycerohydrogels based on chitosan d-ascorbate have higher mechanical strength and elasticity under uniaxial stretching and lower values of Young’s modulus. It has been shown that the systems based on chitosan d-ascorbate show the greatest antibacterial activity against Staphylococcus aureus 209P and Escherichia coli 113-13 and significantly promote the viability of normal human dermal fibroblasts. The results of our assessment of the biological properties of chitosan polysalts are unexpected, since ascorbic acid exhibits biological activity as its l-isomer only.

The age of inflammatory periodontal disease (PD) manifestations has tended to decrease over the past decades. The study of the range of periodontal pathogens in young people and their influence on the PD manifestation contributes to the predictor identification for the early prevention of this pathology.The aim was to study the correlation between the range of periodontal pathogens in the dentoalveolar sulcus/periodontal pocket (DS/PC) contents and the clinical PD manifestations in young people.We examined 28 patients (23.1 ± 0.93 years) with dental biofilm-induced gingivitis (BG), 24 patients (30.7 ± 0.6 years) with aggressive periodontitis (AgP), and 87 clinically periodontally healthy patients (21.1 ± 0.49 years) (Control). The hygiene index and the periodontal status were determined in all patients. DNA of five periodontal pathogens was identified by PCR in the DS/PC contents. The statistical analysis was performed in Statistica 13.3. The critical significance level was p ≤ 0.05.DNA was not observed in 60.9 % of the control group samples and 7.1 % of the BG group samples. In other cases, the bacteria were found separately and as part of bacterial complexes. P.g. and T.f. were most often detected in all groups. P.g. (U = 474, р < 0.01) and A.a. (U = 209, р >< 0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р >< 0.05 and U = 34, р >< 0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ2 = 5.53, р >< 0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group. The association of periodontal pathogens and their complexes with different PD forms was revealed.>< 0.01) and A.a. (U = 209, р <0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р <0.05 and U = 34, р <0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ² = 5.53, р <0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group.The association of periodontal pathogens and their complexes with different PD forms was revealed.

A comprehensive study of the structure, properties and biological functionality of salt chitosan complexes with L- and D-aspartic acid (AspA) was carried out. It has been established that these polymer salts differ in their spatial organization, chirooptic characteristics, surface charge and macrocoil size. In experiments in vitro on a wide range of biological objects (unicellular algae, planktonic crustaceans, aerobic bacterial microorganisms, cell cultures and test plants), it was found that the chitosan salt with D-AspA exhibited the best biological activity. The results obtained confirm our hypothesis that the biological homochiral hierarchy principles are most consistent with the chitosan (D-aminoglycan) derivatives with the D-antipode of the acid.

-defensin-2 (HBD-2) is a peptide of innate immunity that provides the first defenсe line in the oral mucosa against invading pathobionts. Under inflammatory conditions, epithelial cells and gingival fibroblasts produce HBD-2. The defective defensin secretion may play a crucial role in the development of inflammatory periodontal diseases. The study was aimed at comparing HBD-2 levels in the gingival fluid and/or periodontal pockets in patients with dental plaque-induced gingivitis (PG), aggressive periodontitis (AgP), chronic generalized periodontitis (CP) and in the periodontally healthy subjects (Control). We examined 142 patients (45.01.03 years) residing in Moscow, including 11 patients with PG (35.73.69 years), 43 patients with AgP (35.40.84 years), 71 patients with CP (54.40.86 years) and 17 controls (36.12.92 years). We assessed the periodontal tissue condition in all patients during the periodontal and X-ray examination. The samples of the gingival crevicular fluid and periodontal pocket contents were collected from the gingival sulcus and periodontal pockets at 8 teeth of both jaws by paper points. The concentration (C) of -defensin-2 was determined by enzyme immunoassay (ELISA Kit for Defensin Beta 2, Cloud-Clone Corp., USA). MannWhitney U-test (U), the KruskalWallis test (H) and the DwassSteelCritchlowFligner post hoc test (W) analyzed a difference significance between the parameters. We estimated the parameter relationship and its power by using the Spearmanʼs rank correlation coefficient (rS). The critical significance level was p 0.05. The current study showed that the progression of the periodontal inflammation is accompanied by sharply decreased HBD-2 concentration in patient samples (H = 42.8, df = 3, р 0.001). Thus, the concentration of HBD-2 in the gingival crevicular fluid of the periodontally healthy subjects (control group) ranged from 225 to 1720 pg/ml (C = 738 [477; 1114] pg/ml). In patients with PG, the median value of peptide concentration was 242 [42.5; 610] pg/ml (Cmin = 19 pg/ml, Cmax = 1000 pg/ml). In patients with periodontitis, it declined to critically low levels: CAgP = 54 [3; 195] pg/ml (Cmin = 0, Cmax = 478 pg/ml) and ССP = 25.5 [0; 125] pg/ml (Cmin = 0, Cmax = 298 pg/ml). Thus, we can consider the level of HBD-2 in the gingival crevicular fluid as a potential predictor for developing inflammatory periodontal diseases.

Biochemical, biophysical and optical aspects of interaction of low-coherent light with bacterial cells have been discussed. Influence of low-coherent speckles on the colonies grows is investigated. It has been demonstrated that effects of light on the inhibition of cells (Francisella Tularensis) are connected with speckle dynamics. The regimes of illumination of cell suspension with purpose of devitalization of hazard bacteria, caused very dangerous infections, such as tularemia, are found. Mathematical model of interaction of low-coherent laser radiation with bacteria suspension has been proposed. Computer simulations of the processes of laser-cells interaction have been carried out.