Betulin exhibits a broad spectrum of biological relevance, including anticancer activity. Due to this, betulin and its derivatives, e.g. betulin disuccinate (DBB), can be used as new potential therapeutic agents. The presence of two carboxyl groups in DBB allows for the preparation of polyanhydrides.

The aim of this work was to obtain betulin-based highly branched polyanhydrides with star- or comb-shaped architectures. Branched polymers offer significantly different physical properties from linear polymers and can provide several advantages for drug delivery applications.

In this study, we develop novel highly branched polyanhydrides with different DBB contents and different architectures through the two-step melt polycondensation of DBB and polycarboxylic derivatives of succinic acid oligomers (OSAGE-COOH and PSAGE-COOH). The content of DBB in the polymers ranged from 70 to 95 wt %. The use of OSAGE-COOH as a branching agent allowed us to obtain star-shaped polymers, while the use of PSAGE-COOH resulted in comb-like polymers. The protein-staining sulforhodamine B assay, developed by the National Cancer Institute for in vitro antitumor screening, was employed in this study for the determination of the cytotoxic activity of the polymers.

The physicochemical properties of the polymers varied depending on the content and structure of DBB. All the obtained polymers released DBB as a result of hydrolysis under physiological conditions and exhibited cytostatic activity toward cancer cell lines while being non-toxic to normal cells. The obtained results offer a promising area for further research into these copolymers' use in medicine.

Branched betulin-based polyanhydrides exhibit anti-cancer activity; thus, they can be used as a polymeric prodrug. Due to their biodegradability and non-toxicity, they are also ideal candidates for carriers of other biologically active substances.

In recent years, the synthesis of metallic nanoparticles using plant-based extracts has gained much importance due to its ease and the economic advantages it offers in terms of material sustainability. These nanoparticles, when supported on biocompatible polymers, provide added benefits for biomedical applications.

This study investigates the green synthesis of silver nanoparticles (AgNPs) using spinach leaf extract and their application in dye degradation. The synthesized AgNPs, characterized by UV-Vis spectrometry, exhibited a significant absorbance peak around 400 nm, confirming successful nanoparticle formation. Three samples with varying concentrations of spinach extract and silver nitrate (AgNO₃) were analyzed, revealing that sample 2 had the highest concentration of AgNPs. The effect of calcium chloride (CaCl₂) concentration on alginate bead characteristics was assessed, with 5% CaCl₂ beads showing superior catalytic activity in degrading 2-nitrophenol, methyl orange, and Congo red. The AgNP-loaded beads demonstrated remarkable degradation efficiencies, achieving approximately 90% reduction for 2-nitrophenol and 85% for methyl orange within 30 minutes. In contrast, sodium borohydride alone did not facilitate Congo red degradation, but AgNP beads effectively reduced its concentration, likely through adsorption and catalytic action. This research highlights the potential of spinach-mediated green synthesis of AgNPs as effective and eco-friendly materials for environmental remediation and medical applications.

The antibacterial properties of the nanocomposite beads were studied using the broth method against two different strains of bacteria, Escherichia coli and Staphylococcus aureus. Antibacterial properties were studied as a function of the number of nanocomposite beads (5, 10, and 20). The material exhibited excellent antibacterial activity against these bacteria, even with a minimum of five beads. Further experiments are in progress, and this study opens the door for point-of-use disinfection of water and material sustainability.

With the rapid expansion of the smart wearable device market, the demand for advanced materials and technologies with high sensitivity and stability is growing significantly. This paper presents an innovative technique for fabricating polyacrylonitrile (PAN) nanofiber membranes via electrospinning, using polyvinylpyrrolidone (PVP) as a pore-forming agent. The nanofibers were carbonized at high temperatures to obtain porous conductive carbonized nanofiber membranes, which were further compounded with thermoplastic polyurethane (TPU) using vacuum filtration to enhance mechanical flexibility and integration potential.

To evaluate the sensor's performance, sensitivity, response time, detection limit, and stability tests were conducted. The resistance change under pressures ranging from 0–50 kPa was measured, yielding a sensitivity of 101.22 kPa⁻¹, demonstrating excellent pressure sensing capabilities. Using precise dynamic loading equipment, the response time was recorded as only 20 ms, ensuring rapid signal transmission. By gradually reducing the applied pressure, the minimum detectable pressure was determined to be 5 Pa, indicating the ability to detect subtle pressure changes. Stability tests revealed that after 7000 loading/unloading cycles, the resistance remained stable with negligible variation, demonstrating exceptional durability and reliability.

This porous conductive carbonized nanofiber membrane shows broad application potential in fields such as smart textiles, biomedicine, and environmental monitoring. In particular, it enables the development of efficient and accurate health monitoring systems in smart wearable devices, supporting continuous physiological and environmental data collection. These findings provide a solid foundation for further research into high-performance composite materials and sensor interfaces, paving the way for innovations in the field of smart materials.

Hemostasis is the first stage of the wound healing process activated upon injury, that results in the control of bleeding and the formation of a protective barrier. The mechanism of hemostasis includes 1) vasoconstriction, 2) the formation of a platelet plug, and 3) blood coagulation. During the hemostasis process, wound infection can exist, inhibiting epidermal maturation, and may cause bacteremia, sepsis, and multiple-organ dysfunction syndrome. In cases of severe wounds, the use of hemostatic products with antimicrobial properties is necessary to compensate for the compromised first step of wound closure. Chitosan (CS) is a naturally derived polymer that plays a leading role in the development of new hemostatic products. CS is a cationic polysaccharide with bactericidal properties; it is renewable, nontoxic, biodegradable, and hydrophilic with high reactivity, and promotes coagulation, flocculation, and biosorption. The hemostatic properties of chitosan are due to direct electrostatic interactions between negatively charged red blood cells and platelets and the positively charged CS. Researchers and pharmaceutical companies are focusing on the hemostatic properties of CS by formulating it into several hemostatic products. Ongoing research is focusing on advanced hemostatic CS-based materials with enhanced antimicrobial properties, good biocompatibility, rapid hemostatic ability, and low manufacturing cost. Hence, in this work, CS was combined with polyvinyl alcohol (PVA) and carboxymethyl cellulose or starch to prepare well-cross-linked patches with enhanced mechanical properties and blood sorption as well as immediate hemostatic properties. Additionally, ZnO and Camphor were added as natural antimicrobial agents to ensure a healthy environment, avoiding potential infections during hemostasis treatment. The successful synthesis of the fabricated CS-based patches was confirmed by FTIR, their crystallinity was researched by XRD, and water swelling was also investigated. Moreover, an investigation of the hemostatic capacity of the dressings was carried out via hemolysis and blood clotting time experiments.

Wounds disrupt the proper function of the skin, and the use of biocompatible films ensures the right conditions for wound healing, prevents microbial infection and thus leads to skin regeneration. Chitosan (CS) is a natural polymer with healing properties, and polyvinyl alcohol (PVA) is a synthetic, biocompatible polymer which increases mechanical properties. In this study, the films used are based on biocompatible hydrogels that are produced via the action of hyaluronic acid (HA) as a natural cross-linker and the interactions between the polymeric chains of CS, PVA and HA. The incorporation of curcumin (Cur) (a natural antimicrobial agent) ensures the protection of the wound against pathogenic microbes. The combination of these materials offers a novel approach to enhancing the water sorption, stability and functionality of wound-healing films. Thus, two groups of films were prepared—CS/PVA@HA and CS/PVA@HA/Cur—with varying concentrations of HA (0.5, 1, 2, 3% w/w) and a fixed concentration of PVA (1% w/v), CS (2% w/v) and Cur (0.1% w/w). The characteristic peaks of the films in FTIR appear to be slightly shifted, which confirms the cross-linking between the chains, while XRD is included. Moreover, swelling and stability assays proved that CS/PVA@HA and CS/PVA@HA/Cur containing 2% w/w HA exhibited optimal behavior under conditions of swelling and stability at pH 5.6 and 7.4, respectively. The results of the experiments confirmed the successful synthesis of the films via our physical cross-linking method. It was found that the incorporation of HA in the CS/PVA polymer network increased the water sorption and swelling behavior of the prepared materials. Therefore, the biocompatibility and the cell growth capacity of the films were also confirmed. Thus, they have potential as wound dressings, with easy formation and improved bio-evaluations for wound-dressing applications.

This study investigates the use of a liquid pharmaceutical drug as a corrosion inhibitor for copper in 1M perchloric acid, aiming to explore environmentally friendly corrosion protection solutions.

Response Surface Methodology (RSM) was employed to optimize and model the inhibition efficiency based on key experimental parameters: drug concentration (0.1% to 0.5%), temperature (20°C to 60°C), and immersion time (0.5 to 1.5 hours).

A quadratic model was developed to predict inhibition efficiency. Upon careful examination of the main effect coefficient plot, it was observed that a negative sign in the coefficients signifies an antagonistic effect of the factors on inhibition efficiency, whereas a positive sign indicates a synergistic effect, enhancing the efficiency of the inhibitor. The optimization process identified conditions that yielded the highest inhibition efficiency (99.71%), specifically at a drug concentration of 0.49%, a temperature of 20.71°C, and an immersion time of 1 hour. The experimental design was validated by a high coefficient of determination (R² = 0.994), an adjusted R² of 0.986, and a predictive Q² value of 0.945, all of which indicate strong model reliability.

This study highlights the practicality of repurposing pharmaceutical compounds for corrosion inhibition, thereby contributing to green chemistry by promoting the use of environmentally benign substances. The successful application of RSM underscores its utility in optimizing corrosion inhibition processes. The findings encourage further exploration of pharmaceutical inhibitors in various corrosive environments, suggesting potential advancements in sustainable corrosion protection strategies.

Hydrogel electrolytes (HEs) represent a transformative advancement for zinc-ion batteries (ZIBs), particularly in wearable and flexible electronics. These electrolytes are especially suited for small form factor ZIBs due to their flexibility, lightweight properties, and reduced leakage risks, but emerging trends suggest potential scalability for large-scale energy storage applications. Compared to state-of-the-art aqueous electrolytes, HEs offer significant advantages, including a reduction in side reactions, an increase in energy density, and enhanced compatibility with flexible substrates. This study analyzes 51 patent documents, including 48 applications and 3 granted patents, focusing on the formulation and application of HEs in ZIBs. International Patent Classification (IPC) data reveal that 14% of the patents pertain to HEs based on copolymers derived from compounds with unsaturated aliphatic radicals containing amides, such as acrylamide and methacrylamide. Similarly, 14% emphasize electrolytes solely composed of polymeric materials (e.g., gel-type or solid-type). Processes for treating macromolecular substances, such as hydrogels, constitute 12% of the patents, while 8% target crosslinking processes like the vulcanization of macromolecules. Patents involving copolymers with oxygenated carbonamido radicals account for 6%, underscoring diverse approaches to material synthesis and optimization. China leads this innovation landscape, with Anhui University and the City University of Hong Kong emerging as primary contributors. Patent classification data also indicate that many patents target technologies aligned with greenhouse gas mitigation, such as viscoelastic HEs for energy storage. These findings underscore the promising future of HEs in ZIBs, supported by active research and development efforts focused on eco-efficiency, high capacity, and sustainability.

The appropriate arrangement and choice of building materials can reduce or even eliminate the risk of hygrothermal problems. The combination of building envelope materials and construction processes can improve a building's response to temperature and humidity, and thus the well-being of its inhabitants. This work analyzes three cases of exterior-exposed perimeter wall configurations (brick/air curtain/brick; brick/ adobe /brick; brick/rockwool/brick), using COMSOL multiphysics simulation software. A coupled three-dimensional heat and moisture transfer model was developed and numerically solved using a finite element method to study and compare the effect of replacing the insulation and air space between the two hollow brick walls with the adobe wall on the comfort level of the building's indoor environment.

Input data and assumptions were required. The model studied was assumed to be located in a warm climate, and the climatic data were extracted from the weather station close to the site studied. The results demonstrate the effectiveness of the hybrid wall (brick/ adobe/brick) in regulating indoor conditions thanks to its high thermal mass and insulation compared with those of typical walls (brick/air blade/brick); it can therefore be an alternative to insulation.

The results of this study are interesting in terms of the thermal and hydric performance of double partitions with adobe insulation.

The embedding of metal oxide nanoparticles into polymeric matrices creates composite materials with interesting physicochemical properties and potential applications in various fields, such as environmental and food monitoring, optical devices, and biosensors.

In the present paper, In₂O₃-based composites were prepared by an ex situ method, where In₂O₃ nanostructures were dispersed into a nafion matrix through an ultrasound mixing process under rigorous control of the process parameters (time, temperature, ultrasound intensity, frequency, etc). The morphological and structural behaviors of the composites were evaluated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD), and the surface-wetting capacity was determined by contact angle (CA) measurements. Morphological analysis showed that the In₂O₃ nanoparticles were uniformly distributed in the nafion matrix, with a slight tendency to agglomerate. The structural investigation revealed a slight shift in the characteristic In₂O₃ peaks, indicating a good interaction between the main phase characteristics of the composite. Nafion exhibits high hydrophobicity properties, and by adding In₂O₃ to the matrix, a decrease in the contact angle at approximately 91° was observed while maintaining hydrophobicity. The electrochemical performance of the composites was evaluated by cyclic voltammetry. This study provides new insights into composite materials and highlights their performance in the development of biosensors, focusing on the properties of composite films.

Acknowledgments: This work was supported by the Core Program within the National Research Development and Innovation Plan 2022-2027, carried out with the support of MCID, project no. 2307 (µNanoEl).

A basic element in frame construction is the beam–column joint. Despite numerous studies, there is still no uniform procedure for designing shear force in different countries. We are still witnessing serious problems and even the destruction of buildings under seismic effects caused by failures in the frame beam–column connection. Over the past six decades, a huge number of experimental studies have been carried out on frame assemblies, where various parameters and their compatibility under cyclic impacts have been tracked. What continues to remain incompletely understood is the magnitude and distribution of the forces passing through the joint. The creation of a new mathematical model of the beam and column that transmit their forces in the frame joint contributes significantly to clarifying the flow of forces. For this purpose, the full dimensions of the beam, as well as its material properties, are taken into account. All research was performed for a stage before the opening of a crack and after its appearance and growth on the face of the column separating it from the beam. In the present paper, the loading of two transverse, uniformly distributed loads, remaining symmetrical on the beam, is considered. The position of the loads for which there is an extremum of the forces contributing to the shear force is investigated. Numerical results are demonstrated for the influence on the magnitudes of the support reactions from different concrete strengths of the beam. The obtained results are compared with those specified in Eurocode for shear force design. It was established that at the appearance of the crack, the shear force determined with the proposed new model exceeds the magnitude of the force calculated by Eurocode.