Key Engineering Materials Vol. 1029

Abstract: This scientific study presents experimental results of particle agglomeration and dispersing processes under various physicochemical conditions, focusing on the effects of temperature, particle concentration, and medium viscosity. Using numerical approaches and experimental data, patterns describing the changes in agglomeration rate and the features of dispersing system stability were identified. The key findings of the research include: the influence of temperature on agglomeration, high particle concentration, medium viscosity, dispersion under low particle concentration conditions. It is noteworthy that the results also confirm an exponential dependence of the agglomeration rate on temperature. However, at high particle concentrations, this effect is mitigated by the dominance of interparticle interactions, such as Van der Waals forces and electrostatic effects. Furthermore, in systems with low particle concentration and elevated temperature, agglomeration processes significantly slow down, indicating improved dispersing stability. The study opens new perspectives for controlling particle agglomeration and dispersing based on temperature, concentration, and the physical properties of the medium. The obtained data can be useful for improving existing technologies and developing new ones in areas where controlling the behavior of dispersed systems is essential.

Abstract: This scientific work presents the development of a computer-simulation model for particle filling in three-dimensional space based on molecular dynamics methods. The Lennard-Jones potential was used to simulate interactions between particles, and the equations of motion were integrated using the Velocity Verlet algorithm. The model incorporates periodic boundary conditions (PBC), ensuring accurate representation of an infinite system without boundary effects. The simulation results confirm the system's energy stability: the total energy remains virtually unchanged throughout the simulation, indicating the correctness of numerical integration. Fluctuations in kinetic and potential energies demonstrate normal system dynamics, where energy is redistributed among particles through interactions. An analysis of the spatial distribution of particles revealed that the system remains in a liquid state, with no signs of solid structure formation or particle aggregation. Notably, the developed model enables the simulation of complex physical processes such as dense structure formation, particle transport, and self-packing. The obtained results highlight the efficiency of the molecular dynamics method for analyzing granular and particulate media, as well as for studying the physical properties of multi-particle systems. The model can be utilized to optimize technological processes related to material transportation, packaging, and storage, as well as for research into nanomaterials and composites.

Abstract: Due to the super-linear growth of the number of particle (especially, proton) therapy centers in 2010–2018, many researchers forecasted the number of patients treated by proton therapy to reach 500–550 thousand before 2026. However, the real farther overall spread of hadron therapy was much slower due to its high cost, very high research intensity, and very high requirements for medical and engineering staff, so that by the end of 2026 the number of patients will reach only 410–415 thousand, clearly tending to saturation with an ever decreasing share of ion therapy and showing that the increase of the biological efficacy and safety of proton and especially heavy ion therapy is it is an urgent need of today’s time. The most promising and experimentally substantiated concept of the whole body and the highly localized combination cancer therapy was developed and tested by Japanese and Georgian researchers in 2015–2020, which clearly demonstrated the high efficiency of the highly localized multicomponent combined therapy of cancer. This paper reports in vitro and in vivo data on the relative anticancer efficacy and acute toxicity of the 50 various multicomponent nanoparticle containing anticancer combinations in comparison to the widely used anticancer drugs gemcitabine, carboplatin, cisplatin and paclitaxel systematically applied against the Non-Small Cell Lung Cancer (NSCLC), clearly showing that the newly developed combinations can be several times more efficient and have a several times less toxicity than the usually applied anticancer drugs. The obtained data also provide sufficient reasons to conclude that the significant increase in the effectiveness of combined formulations is caused by the super-additive synergistic interaction of nanoparticles and of the active components of anticancer mixtures. It is especially important that the newly developed “cocktails” reveal a 3 to 10 times increased therapeutic window due to several times increased necrotic and apoptotic activity against the cancer cells in comparison to healthy tissue cells, drastically increasing the therapeutic value of the drugs due to higher efficacy, higher safety and significantly reduced duration and costs of treatment.

Abstract: Cancer and cardiovascular diseases are the leading causes of global morbidity and mortality, being in 2023 responsible for about 24 and 35% of deaths, respectively. In addition, they reveal a bidirectional association and demonstrate a significant super-additive impact on each other. Combination therapy of cancer effectively targets and affects pathways that play important roles in causing and sustaining malignant cell induction and progression. Alkali metal solutions are among the intensively studied anticancer agents, whereas cesium chloride is a popular alternative highly consumed anticancer BAD. The results reported clearly show that rubidium chloride solution reveals the highest biological efficacy and selectivity to cancer cells among the four types of tested samples, which is rather difficult to interpret in the frame of the cancer high-pH therapy concept. This is why the next stage of the research should be focused on the measuring the alkalinity and cesium content in the intracellular area of the exposed cells.

Abstract: Studying the spectroscopic properties of nanomaterials and nanoparticles is essential for developing nanomaterial science and nanotechnology. Spectroscopic properties of nanoparticles of biological origin, especially pathogenic nanoparticles such as viruses, became actual after the Covid-19 pandemic, causing economic, human and social harm. Known spectra of the utmost atoms, molecules, and compositions are well used for identification. In this paper, we provide a concise review of the experimental results obtained from advanced spectroscopy techniques by various scientific groups and demonstrate the possibility of using spectra of viruses to detect and identify diseases caused by pathogens. Raman, ultraviolet (UV), and infrared (IR) spectroscopy methods for experimental study of viral materials are considered.

Abstract: Recently, a major challenge in scientific research in nanomedicine has been effectively delivering medication to the local area of the disease or tumor. This approach aims to maximize clinical benefits while minimizing the side effects of the drug. Additionally, there has been a growing focus in modern medicine on photochemical and photothermal therapy for both malignant and nonmalignant tumors. The main goal of the research was to study the reduction process of silver ions on drug delivery nanoparticle - G4 PAMAM (polyamidoamine) dendrimers with different terminal functional groups, NH₂ and OH, using absorption spectroscopy and create new, stable nanosized metalorganic nanocomposites. For the reduction of silver ions, sodium borohydride was used. In the case of G4(NH₂) PAMAM dendrimer, the silver nanoparticles are created inside the dendrimer, while in the case of G4(OH) PAMAM dendrimer, the reduction occurs on the surface of the dendrimer. There were determined the adsorption rate constants and the adsorption energy of the silver atom on PAMAM dendrimers.