For the first time, studies were conducted to evaluate the susceptibility of bacterial biofilm cells to an antibiotic by using a compact acoustic sensor system based on a lateral electric field resonator. The antibiotic’s activity against the bacteria was indicated by the change in the sensor system’s analytical signal for the antibiotic-exposed biofilm bacteria. The results were confirmed by microbiological culturing and microscopy data. The advantages of this approach include the ability to repeatedly use the sensor system outside the laboratory and obtain results within a short period (10 min).
The use of the redox indicator resazurin for estimating the intracellular activity of the original derivative of pyrano[3,2-b]indolone Pyr056 with anti-tuberculosis activity in vitro was proposed in the work. The estimation of the number of M. tuberculosis in the cultures of infected macrophage cell line RAW264.7 treated with Pyr056 by counting CFU and by measuring the fluorescence intensity of reduced resazurin demonstrated a high degree of positive correlation (r = 0.982). On the one hand, this result opens up the prospect of further study of the anti-tuberculosis activity of Pyr056, including in vivo experiments; on the other hand, the possibility of using resazurin for rapid and accurate estimation of the efficiency of experimental compounds against various intracellular pathogens, including M. tuberculosis, especially in the case of limited time and resources.
The emergence of drug resistance in microbial cells is a serious public health problem. Therefore, the development of new alternative antibacterial agents to combat multidrug-resistant bacteria is becoming increasingly important. The rapid development of nanotechnology and nanoparticle synthesis has facilitated the emergence of new strategies for combating microbial cells. Silver nanoparticles, which possess antibacterial activity, are particularly valuable. Nanoparticle synthesis involves various physical and chemical methods using toxic reagents that pollute the environment. Therefore, cost-effective alternative processes for synthesizing nanomaterials using biological systems, biological or “green” nanoparticle synthesis, are being actively developed. Natural biological sources, including fungi, bacteria, plants, animal cells, viruses, and their metabolites, can be used for green nanoparticle synthesis. The use of biological objects to create inorganic nanoparticles is a relatively new area of biotechnology. Green synthesis of noble metal nanoparticles is a vast and growing area of research. This paper presents the basic principles of green synthesis technology for producing silver nanoparticles, as well as the advantages and disadvantages of its application. The potential for using nanoparticles obtained using green synthesis technology as antimicrobial agents is discussed.
The extraction of lignin was carried out from corn cobs, pine and aspen sawdust using a deep eutectic solvent choline chloride/oxalic acid (molar ratio 1 : 1). The extracted lignins were characterized by UV-visible and Fourier transform infrared spectroscopy methods. Their antioxidant and UV-protective properties were compared. Lignins from the pine and aspen had a high antioxidant activity towards DPPH• and ABTS+• free radicals, while lignin from the corn cobs had the highest adsorption capacity towards the synthetic dye methylene blue (30.8 mg/g). All three lignins demonstrated a high efficiency as an active component of UV-shielding films and can be used in food packaging and cosmetics.
The review discusses the enzymatic reduction systems that maintain animal heme-containing globins in a physiologically active state. There are two types of reductases. Specialized systems (two-component: cytochrome-b5 reductase/cytochrome b5) provide rapid reduction of hemoglobin (Hb) and myoglobin (Mb), which is important for oxygen transport and storage. The main enzyme, CYB5R3, reduces Hb, Mb, and presumably cytoglobin (Cygb) and neuroglobin (Ngb). CYB5R4 most probably preferentially works with Cygb and Ngb in tissues with low activity of CYB5R3. Reductases with wide specificity, thio-reductase 1 (TXNRD1) and NADPH:cytochrome-P450 reductase (CPR), function as reserve systems. In addition to their role in antioxidant protection and detoxification, they effectively reduce globins (especially Cygb and Ngb), showing the relationship between cell’s redox status and globin functions. All these systems not only support oxygen transport function of globins, but also regulate nitric oxide metabolism, providing vascular tone and protection against hypoxia and oxidative stress. Their dysfunction leads to pathologies, the most severe of which is hereditary methemoglobinemia.
A comparative assessment of the effect of two structurally different chitosan–silver nanocomposites (Ch–Ag 1 and Ch–Ag 2) on plant resistance to Phytophthora infestans, the state of the pro-/antioxidant system, the transcriptional activity of PR protein genes, and potato productivity was carried out. The dependence of the biological activity of Ch–Ag nanocomposites on their structure has been revealed. The mechanisms of activation of potato defense systems under the influence of Ch–Ag nanocomposites were mediated by the accumulation of hydrogen peroxide, a decrease in catalase activity, and an increase in the transcription of genes encoding PR proteins: chitinase (PR-3), thaumatin-like protein (PR-5), RNase (PR-10), and methyltransferase (MT). It was shown that treatment with Ch–Ag 2 reduced the degree of damage to the leaves of P. infestans and increased the mass of potato mini-tubers. The data obtained indicate that chitosan–silver nanocomposites are promising biological products for increasing the stability and productivity of potatoes.
A comparative study of the effect of linear chitosan (Сh) and the globular form of chitosan, novochizol (Nc), on the growth and development of spring bread wheat, as well as protection against a complex of fungal diseases under epidemic conditions, was carried out. The indicators “Area Under the Disease Progress Curve” (AUDPC) and “Resistance Index” (RI) were calculated based on the observations. The research results showed that the Ch had greater growth-stimulating activity (on seed germination, stem and ear formation, and seed setting) and a protective effect against biotrophic and hemibiotrophic pathogens than Nc. The Nc–SA preparation (complex with 0.01
The insoluble complexes formed by polyphenols from plant extracts and chitosan are of interest as potential delivery systems for polyphenols in the intestine. The complexes formed by polyphenols from an aqueous sage extract and chitosan have been investigated. These complexes have been shown to be stable in neutral media and to release polyphenols in highly acidic and highly alkaline environments. The complexes demonstrated significant polyphenol release in simulated intestinal fluid, with minimal release in simulated gastric and salivary fluids. It has been demonstrated that the complexes formed with chitosan are primarily composed of flavonoid glycosides and phenolic acids, with flavonoid aglycones present in trace amounts.
This review presents a summary of the diverse range of chitosan applications that have been developed recently: from biomedicine, agrobiotechnology, biostimulation, and bioprotection to climate change adaptation, among others. The focus is on the functionalization and controlled optimization of key biopolymer parameters: degree of polymerization, degree of acetylation, distribution of acetylated blocks within the biopolymer chain, density, and cross-linking reagents. The development of chitosan-based systems for encapsulating drugs and vaccines described in this review improves precision drug delivery. The biologization of agriculture is reflected in this review through studies devoted to the use of chitosan as a protective agent against abiotic stresses, such as drought, high and low temperatures, and soil salinization. By focusing on new strategies for the combined use of chitosan and plant-associated soil bacteria, the use of chitosan nanoparticles demonstrates the expanding scope of biopolymer applications in the agricultural sector. The presented discussion of the mechanism of chitosan action on the immune system of plants provides a deeper understanding of how to achieve the targeted effects of bioprotection and biostimulation.
Hybrid hydrogels formed in situ on the wound surface are considered promising materials for reconstruction and therapy. This paper examines the dermo- ex vivo and mucoadhesive properties in vitro, as well as the antibacterial, hemostatic, and wound-healing activity in vitro and in vivo of glycerohydrogels based on chitosan hydrochloride, glucomannan, silicon tetraglycerolate (a sol-gel precursor), and functional additives. When applied to an intact or wounded dermal surface, the gel-forming composition results in the formation of a protective glycerohydrogel coating (gel film) with explicit adhesive and sorption properties forms in situ within 3–5 minutes. This coating exhibits bacteriostatic and haemostatic action, as well as wound-healing activity. In vivo evaluation of the wound-healing effect showed a statistically significant reduction in skin restoration time compared to the control, allowing us to recommend glycerohydrogel films as effective bioresorbable wound dressings.
This paper proposes a method for producing a macroporous cryostructured hydrogel material based on chitosan cross-linked with a low-toxicity agent, vanillin. The method involves a two-stage process: cryostructuring followed by freeze-drying and thermal cross-linking, resulting in the formation of Schiff bases. The resulting material is characterized by a developed system of interconnected pores with an average size of approximately 60 μm, a high swelling rate, and sufficient mechanical properties determined by its porous structure. The selective antibacterial activity of this material against Staphylococcus aureus (growth inhibition rate of 24.3
In the context of growing antibiotic resistance, the possibility of creating non-toxic and biodegradable film coatings based on chitosan with modulated antibacterial properties is highly relevant. We have analyzed 270 samples of biopolymer films based on chitosan cross-linked with genipin with molecular weights of 60, 190, and 320 kDa. Suspensions of 30 clinical strains of Staphilococcus aureus (n = 10), Escherichia coli (n = 10), and Candida albicans (n = 10) microorganisms at a concentration of 103 CFU/mL have been used to evaluate the antibacterial activity of the biopolymer chitosan films (CF). Depending on the molecular weight of chitosan and the contact time of the biopolymer films with S. aureus, E. coli, and C. albicans, negative dynamics in the number of viable colonies have been revealed. These results suggest that chitosan-based biopolymers hold promise for the development of medical tools with programmable antibacterial and antifungal properties for practical medical use.
This work describes the synthesis of the chitosan nanoscorbate complex from Bombyx mori with aluminum ions based on chitosan and ascorbic acid using the ionotropic gelation method. Their physicochemical and antimicrobial properties against Fusarium oxysporum, which causes diseases in agricultural crops, are studied. The obtained chitosan nanoscorbate with aluminum ions has a larger inhibition zone compared to all variants against Fusarium oxysporum, which allows its use for presowing seed treatment with the component ratio of CS : AA : Al of 4 : 1 : 0.5.
Regenerated fibroin isolated from natural silk and mixed solutions of it with chitosan were used to obtain cryostructurates—macroporous hydrogel matrices intended for application in tissue engineering as carriers for cell culturing. The conditions for stabilizing the structure of such biopolymeric carriers by cross-linking fibroin (Fb) and chitosan (Chit) with genipin (Gp) in alcohol solutions and the features of cell growth on the obtained materials were studied. Investigation of the interaction of genipin with fibroin and chitosan acetate showed that the reaction rate leading to the cross-linking of macromolecular chains of amino-containing biopolymers, as well as the concentration of the genipin conversion product, can be significantly increased compared to using the individual protein. With the use of confocal laser scanning microscopy, the structure of macroporous carriers was studied and their ability to support 3D growth of mouse fibroblasts (L929) in an in vitro model was demonstrated. The obtained biomaterials are promising for use in tissue engineering.
This study examines the effects of kojic acid, chitosan, and their combinations with Bacillus subtilis strains on wheat resistance to dark brown spot. A concentration-dependent immunomodulatory effect of the acid on wheat resistance to Bipolaris sorokiniana was identified: B. subtilis VKM B-2604D and B. subtilis VKM B-2605D strains demonstrated high efficacy in protecting wheat from dark brown spot, reducing plant infestation by 50
The effect of pre-sowing treatment of soft wheat seeds of the Darya (K-64432) and Leningradskaya 6 (K-64902) varieties using biologically active chitosan with or without the crosslinking agent glyoxal has been evaluated. Two methods of glyoxal administration have been considered: after the treatment with chitosan and simultaneously with chitosan. The phytometric characteristics of the crops, as well as the phytopathological and other indicators of disease development, have been analyzed. Regardless of the processing method, wheat productivity has been shown to increase significantly (by 188
A comparative study of fungistatic and elicitor activity of chitosan solutions and dispersions of chitosan nanoparticles obtained by fractional precipitation at pH 5.0 (NC-5) and pH 7.0 (NC-7) from chitosan with a molecular weight of 60 kDa was carried out. Both dispersions demonstrated higher fungistatic activity against Bipolaris sorokiniana compared to chitosan solution. A tendency towards a greater effect of inhibition of B. sorokiniana mycelium growth was revealed for NC-5 dispersion compared to NC-7 dispersion. It was found that pretreatment of wheat plants with NC-5 and NC-7 dispersions reduced leaf infestation with dark brown spot by three and two times, respectively, compared to the control. Chitosan solution under the same conditions suppressed disease development by only 10
New data were obtained on the effectiveness of innovative plant protection and growth regulation products based on selected Bacillus subtilis and Trichoderma asperellum T-36 strains and a plant resistance inducer, 0.1
The work has demonstrated that high-molecular chitosan enhances the lytic effect of lysostaphin on Staphylococcus aureus cells. More efficient lysis of bacterial cell walls by lysostaphin in the presence of chitosan made it possible to extract larger amounts of high molecular weight DNA suitable for sequencing from bacterial cells.
An Erratum to this paper has been published: https://doi.org/10.1134/S0003683826010011
