Composites based on Ce or Zr oxides (MeO₂) are highly demanded materials for energy, electronics, catalysis, and nanophotonics, but their development is hampered by high energy costs, difficulties in synthesis, and the lack of sound pressing and sintering modes for nanostructured powders. In this study, a method for producing composite powders based on oxygen-free graphene and MeO₂ for ceramics with a wide range of applications is proposed. The method is a combination of sol–gel and sonochemical techniques, allowing for the synthesis of hybrid structures with a uniform distribution of components in volume at the nanolevel. The developed hybrid structures consist of ceria or zirconia crystallites with dimensions of 6-14 nm, incorporated into graphene sheets several nm thick. Theoretically substantiated mechanisms for the formation of graphene suspensions, graphene–MeO₂ composites, and sintering of nanostructured hybrid powders are proposed based on the obtained experimental data. The positive effect of graphene on the microstructure of ceramics was determined: the use of a hybrid graphene–ZrO₂ powder makes it possible to obtain dense (98%), fine-grained ceramics with high structural homogeneity using the SPS method. It was shown that oxygen-free graphene on the surface of MeO₂ crystallites promotes the acceleration of surface exchange processes involving oxygen, which makes the developed composites promising raw materials for new electrical devices and catalysts. It was determined that graphene sheets and the method of their inclusion in the hybrid structure affect the activation energy of sintering and the mass transfer mechanism. The results of this study can be used as a basis for a technological process covering all stages, from obtaining initial solutions and colloids to sintered ceramics.

The relevance of this work lies in its contribution to water purification through two approaches. On the one hand, using sorbents made from foamed nanographite-structured materials, and on the other,employing eco-safe nanocomposites of carbon nitride with titanium dioxide, which is widely applied as a photocatalyst for water treatment via an advanced method: the generation of reactive oxygen species (ROS).

In the first stage of this work, the hypothesis posited that the earlier TiO₂ engages with and simultaneously synthesizes C₃N₄ during its formation , the more effective the resultant photocatalyst will be.

The first stage of this work included several steps:

1. SiO₂∙xEtOH and HₓTiᵧO₂∙H₂SO₄ sols were prepared and converted into gels: SiO₂∙8.6H₂O and TiO₂∙25.9H₂O (TGA).
2. Annealing in an inert atmosphere (3 h at 500°C; 3°C/min) was performed for melamine and its mixtures with desulfated titanyl sols: SiO₂‧8.6H₂O; TiO₂‧25.9H₂O and nano-TiO₂ P25. TGA modeling demonstrated that mass loss in the presence of TiO₂ was lower than with SiO₂.
3. AFM data revealed that the smallest particle size was observed in the thermolysis products of melamine mixtures either with the sol derived from (NH₄)₂TiO(SO₄)₂ (STA) or with the TiO₂‧25.9H₂O gel.
4. From the mixture of melamine with the STA-derived sol, semi-amorphous nanocrystalline g-C₃N₄ and rutile were formed (XRD). The mixture with the TiO₂‧25.9H₂O gel yielded the same phases, plus anatase.
5. The most effective photocatalyst for methyl orange degradation was C₃N₄ with TiO₂ from the STA-derived sol.

If, under the same temperature program, foamed melamine is subjected to thermolysis, a foamed product reproducibly crystallizes, which, according to XRD, is single-phase nanographite. The nanostructured layered morphology is confirmed by SEM. At the same time, according to CHNS analysis, this product contains carbon and 44% nitrogen. As a sorbent, this material absorbs 11 g/g of gasoline.

Introduction: Researching ways to regulate the biocorrosion rate of biodegradable magnesium implants is one of the most urgent tasks in the field of biomedical materials science. The most important objective is to maintain the corrosion resistance of the material during the initial stages after implantation, when this resistance subsequently decreases. Nanocoatings are the most effective means of achieving this. The present study investigates the potential of oxide nanocoatings to reduce the biocorrosion rate of AZ31 magnesium alloy in physiological Ringer's solution.

Methods: Atomic layer deposition (ALD) was used to create defect-free, uniform coatings based on titanium, aluminium and zinc oxides on AZ31 magnesium alloy surfaces. The thickness, composition, morphology, and structure of the coatings were analysed using ellipsometry, scanning electron microscopy, X-ray photoelectron microscopy, and X-ray diffraction. The biocorrosion rate was assessed by measuring potentiodynamic polarization curves and the mass loss of the samples.

Results: Al₂O₃ nanocoatings with a thickness ranging from 20 to 80 nm, as well as composite Al₂O₃-TiO₂ nanocoatings, are effective in reducing the rate of biocorrosion in AZ31 alloy. Conversely, TiO₂ coatings demonstrate reduced effectiveness and, in some cases, have been observed to slightly accelerate biocorrosion. The effectiveness of TiO₂ coatings was found to depend significantly on the precursor used: titanium tetrachloride or tetraisopropoxide. AZ31 biocorrosion rates were reduced by 18-54 times with Al₂O₃ and 40 nm thick Al₂O₃-TiO₂ composite coatings.

Conclusions: Among the ALD aluminium, zinc, titanium oxides and their composite nanocoatings, the Al₂O₃ and Al₂O₃-TiO₂ nanocoatings are the most effective in reducing the biocorrosion rate of the AZ31 alloy in the initial stages, while ensuring the material's biodegradability in subsequent stages.

This research was carried out under the financial support the Russian Science Foundation grant (project No. 24-73-00115).

With the development of nanotechnology, titania nanoparticles play a significant role in biomedical environmental applications. With the aim of better understanding bio-matrix/nanoparticle surface interactions, studying the influence of amino acids on the colloidal behavior of nanoparticles may provide valuable insights into the formation of the protein corona. In water nanoparticles, surface reconstruction and aggregation are determined to be different under varying pH levels and the presence of amino acids. However, there are not enough data to predict the influence of amino acids on the stability of anatase and rutile nanoparticles in the same conditions. In our work, we examined the colloidal properties of anatase and rutile nanoparticles, with an average size of 26 and 102 nm, respectively, and showed that the addition of five amino acids with contrasting surface charges (glutamic acid, cysteine, glycine, lysine, and arginine) enhances the aggregation of particles in an aquatic medium. In this work, we measured particle size distribution and zeta-potential in suspension with pH values ranging from 3 to 11. It has been revealed that under the same conditions, rutile nanoparticles have a lower pH dependence of the aggregation state compared to those of anatase, which are always more aggregated than rutile nanoparticles. The presence of amino acids tends to shift the pH of the isoelectric point of surface toward acidicity. For the particles in glutamic acid, glycine, and lysine, the highest degree of aggregation is achieved reasonably at a pH close to that of the isoelectric point. A contrasting effect of pH on the behavior of rutile and anatase nanoparticles was found in cysteine and arginine. Our findings showed that in an acidic medium (pH 3–5), aggregation depends more on pH; in a weakly acidic medium (5–7), it depends on the surface of the particles; and in an alkaline medium (7–11), on the nature of the amino acids.

Titanium dioxide (TiO₂) nanoparticles are widely used in various industries due to their low absorption coefficient, high dielectric permeability, good biocompatibility, high hardness, and photocatalytic activity. However, the colloidal properties (size, charge, sedimentation properties) of TiO₂ nanoparticles in aqueous solutions have not been sufficiently studied, and the results of studies are not comparable due to different experimental conditions and the diversity of nanoparticles produced, which limits the application of TiO₂ nanoparticle suspensions.

In this work, we determined the effects of the method (ultrasonic and mechanical) and duration (up to 60 min) of mixing and the pH of the solution (from 3 to 11) on the colloidal properties of TiO₂ nanoparticles in a 10 mM NaCl solution. The concentration of particles was 100 mg/L. Particle size distribution was determined using dynamic light scattering, zeta–potential was measured by using laser doppler electrophoresis, and light transmittance coefficient was estimated by spectrophotometry method. We examined two types of TiO₂ nanoparticles, namely anatase and rutile particles, with average particle sizes of 18 and 83 nm and a phase composition of anatase:rutile 87:13 and 73:27 wt.%, respectively.

It was found that prolonged treatment of suspensions (>30 min) led to surface overcharging and enhanced aggregation and sedimentation of nanoparticles. For both nanoparticles in an acidic environment, suspensions with maximum resistance to aggregation and sedimentation were formed. The sedimentation curves for suspensions were well described by a first-order kinetic equation (R²>0.9). All other things being equal, the behaviour of anatase nanoparticles is more sensitive to the pH value; meanwhile, rutile nanoparticles were more affected by the method of mixing.

The effect of pH and mixing method on the electrokinetic, dispersion, and sedimentation properties of suspensions provides valuable information that can be used to distinguish the colloidal stability of particles in aqueous solutions and broaden the application of TiO₂ nanoparticle suspensions.

Introduction: Magnetic colloids based on iron oxides, specifically maghemite (γ-Fe₂O₃), have emerged as significant nanostructures in biomedicine due to their superparamagnetic properties, which enable targeted therapies, magnetic hyperthermia, and photothermia, as well as functionalities as contrast agents in magnetic resonance imaging. In this context, magnetopolymeric NPs based on γ-Fe₂O₃ nuclei embedded into a poly(ε-caprolactone) (PCL) matrix and decorated with polyethylenimine (PEI) were developed and evaluated. Methods: Preparation of the magnetic nanocomposites (n = 3) was carried out by solvent evaporation. Iron oxide nuclei were obtained by chemical co-precipitation and were surface functionalized with PCL first and then with PEI. Reproducible preparation of these nanohybrids was demonstrated by determining particle size using photon correlation spectroscopy, high-resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FTIR), and electrophoresis (defining the effect of pH on the surface electrical charge of the colloid). Results: the PEI-decorated (γ-Fe₂O₃/PCL) (core/shell) nanohybrids were characterized by an average size of 232.9 ± 3.3 nm (polydispersity index: 0.259 ± 0.001). The evolution of the zeta potential values of the nanohybrids as a function of pH confirmed the successful embedment of the iron oxide cores, first into the PCL matrix, and then the surface decoration of the core/shell particles by a PEI ring. Finally, HRTEM analysis and FTIR spectra confirmed the successful formation of the (core/shell)/shell nanostructure. Conclusions: A reproducible methodology has been proposed for preparing PEI-decorated γ-Fe₂O₃/PCL NPs, which hold promise for applications in biomedicine.

The studied plant extract has demonstrated significant antioxidant, anti-inflammatory, antifungal, antibacterial, anticancer and psycho and neuroactive properties. In cosmetics, it has shown an additional distinctive fragrance, a refreshing sensation and calming effects on the skin. Liposomes are phospholipid bilayer nanocarriers with both hydrophilic and hydrophobic regions, enabling the encapsulation of water-soluble compounds in their aqueous core and fat-soluble compounds in their lipid membrane, making them ideal for incorporating plant extracts, whose bioactive compounds also often exhibit low stability. This study investigates the potential of the nano-encapsulation of a plant extract for enhanced topical delivery. The developed vesicles were produced using thin-film hydration, and lipid 1: lipid 2 ratios were optimized to obtain adequate particle characteristics (60:40, 75:25, 80:20). Particle size and polydispersity index (PDI) were determined by dynamic light scattering using a Zetasizer apparatus. For the determination of the encapsulation efficiency (EE%), a quantification method was developed using UV-Vis spectrophotometry. The results showed that liposomes without the extract exhibited a mean PDI of 0.164 - 0.176 and a particle size of 120.6 - 134.8 nm. After extract encapsulation (at 1, 2, 5 and 10 mg/mL), the mean PDI ranged from 0.180 to 0.434, with particle sizes between 106.5 and 136.3 nm. EE% for 80:20 liposomes ranged from 37 to 71% at 2, 5 and 10 mg/mL, yielding, respectively 1.3, 3.3 and 3.7 mg/mL of extract. The selected vesicles exhibited optimal characteristics with particle sizes below 200 nm and polydispersity index values below 0.200, which ensures stability and homogeneity of the vesicles, as well as effective skin retention, and EE% up to 70% demonstrated effective incorporation of the extract. This study presents a novel liposomal nano-encapsulation of aqueous plant extract, opening new avenues for its pharmacological and cosmetic utilization. Further studies will assess stability, release profiles and antioxidant activity.

Introduction

Alginate is a naturally derived polysaccharide that has been widely studied for biomedical applications due to its excellent biocompatibility and biodegradability. Electrospinning, a simple and efficient technique for producing fibrous mats, is gaining increased attention. However, the electrospinnability of alginates is limited, requiring the optimization of polymer blends and solvents to obtain uniform and stable nanofibers. This study aimed to systematically investigate various alginate/PEO formulations and solvent systems in order to fabricate nanofibers suitable for biomedical use.

Methods

A broad range of polymer concentrations and solvent combinations was tested. Initial electrospinning trials using pure water-based systems failed to produce continuous fibers. The addition of polyethylene oxide (PEO) served to enhance the spinnability of alginate by acting as a carrier polymer. Eventually, a formulation consisting of 3% (w/v) SA and 3% PEO dissolved in an 80:20 (v/v) water/DMSO mixture with 15-20 μl of TritonX-100 as the surfactant resulted in successful fiber formation. Post-electrospinning crosslinking was performed to enhance the stability of the fiber in aqueous environments.

Results

Among over 40 tested compositions, only the optimized blend produced continuous, bead-free nanofibers. The addition of TritonX-100 proved critical in improving spinnability and reducing surface tension. Observation under the microscope indicated a favorable fiber morphology and nanoscale diameter. Crosslinked fibers maintained structural integrity in water, confirming successful stabilization. The final product showed promising features for further biological integration, including high porosity and hydrophilicity.

Conclusion

This study highlights the importance of systematic formulation screening in the development of electrospun alginate-based nanofibers. The optimized composition and processing conditions led to smooth and consistent fibers with potential applications in wound healing, drug delivery, and tissue engineering. Future research will focus on biological characterization, drug encapsulation studies, and in vitro performance assessment.

The design and development of highly active, low-cost catalytic materials play a crucial role in the advancement of electrochemical catalytic technologies. Understanding the true correlation between the structural features of catalysts and their electrocatalytic performance is essential for guiding the rational design of more efficient catalysts. However, currently, most electrocatalysts undergo multiple dynamic reconstructions under operational conditions, involving changes in composition, structure, and morphology, which makes the process of designing effective catalysts heavily reliant on extensive trial-and-error experiments. Although various advanced in situ, real-time, and high spatiotemporal resolution characterization techniques have been developed to monitor the changes in catalysts during operation, there remains a significant discrepancy between the testing conditions of these techniques and the actual working environments of catalysts, leading to challenges in accurately understanding catalytic mechanisms and structure–performance relationships under realistic conditions. In response to this problem, the applicant will base their discussion on recent research achievements, focusing on the stability methods and mechanisms of electrocatalysts composed of single metals, alloys, and compounds. The proposed approach emphasizes starting from the source—namely, the initial design and synthesis—to develop new strategies for preparing catalysts with high activity and stability. This approach aims to establish a deeper understanding of the structure–performance relationship and to provide innovative ideas for the rational design and synthesis of highly efficient catalysts, ultimately advancing the field of electrochemical catalysis and facilitating the development of practical, cost-effective catalytic systems for energy conversion and storage applications.

The precise delivery of nitric oxide (NO) within tumor microenvironments is a promising strategy in anticancer therapy, as NO exhibits dose-dependent cytotoxic effects. Light-activated NO donors offer excellent spatiotemporal control and minimal invasiveness, making them ideal for therapeutic use. Here, we report a water-soluble nanoconjugate, NCDs-1, combining a two-step NO photodonor with blue-emitting, nitrogen-doped carbon nanodots (NCDs). This hybrid nanostructure (~10 nm) displays a new absorption band absent in the individual components, indicating strong ground-state electronic interaction. Upon blue light irradiation, NCDs-1 achieves nearly a tenfold enhancement in NO release compared to the free photodonor, likely due to photoinduced electron transfer between the NCDs and the NO-releasing unit. Notably, its quenched blue fluorescence is restored during the second NO release step, offering a real-time optical signal to monitor NO generation. Alongside efficient NO photorelease, NCDs-1 shows significant photothermal conversion, supporting its application in multimodal therapy. To shift light responsiveness toward more biocompatible wavelengths, we developed a second nanoconjugate, NCDs-2, by altering the solvent during NCD synthesis while using the same precursors (citric acid and urea). This yielded NCDs with absorption shifted into the green region. When conjugated with the same NO donor, NCDs-2 retained excellent NO release under green light—a wavelength with improved tissue penetration and compatibility. Preliminary in vitro studies on cancer cells confirmed the therapeutic potential of both nanoconjugates. These multifunctional platforms represent a promising strategy for light-controlled NO delivery and combined photothermal therapy, with tunable optical properties adaptable to different biological contexts.