Search Results (190)

Background/Objectives: Hot-melt extrusion (HME) has gained prominence for the manufacture of sustained-release oral dosage forms, yet the application of wax-based matrices and their resilience to alcohol-induced dose dumping (AIDD) remains underexplored. This study aimed to develop and characterise wax-based sustained-release felodipine formulations, with a particular focus on excipient functionality and robustness against AIDD. Methods: Felodipine sustained-release formulations were prepared via HME using Syncrowax HGLC as a thermally processable wax matrix. Microcrystalline cellulose (MCC) and lactose monohydrate were incorporated as functional fillers and processing aids. The influence of wax content and filler type on mechanical properties, wettability, and drug release behaviour was systematically evaluated. Ethanol susceptibility testing was conducted under simulated co-ingestion conditions (4%, 20%, and 40% v/v ethanol) to assess AIDD risk. Results: MCC-containing tablets demonstrated superior sustained-release characteristics over 24 h, showing better wettability and disintegration. In contrast, tablets formulated with lactose monohydrate remained structurally intact during dissolution, overly restricting drug release. This limitation was effectively addressed through granulation, where reduced particle size significantly improved surface accessibility, with 0.5–1 mm granules achieving a satisfactory release profile. Ethanol susceptibility testing revealed divergent behaviours between the two filler systems. Unexpectedly, MCC-containing tablets showed suppressed drug release in ethanolic media, likely resulting from inhibitory effect of ethanol on filler swelling and disintegration. Conversely, formulations containing lactose monohydrate retained their release performance in up to 20% v/v ethanol, with only high concentrations (40% v/v) compromising matrix drug-retaining functionality and leading to remarkably increased drug release. Conclusions: This study highlights the pivotal role of excipient type and constitutional ratios in engineering wax-based sustained-release formulations. It further contributes to the understanding of AIDD risk through in vitro assessment and offers a rational design strategy for robust, alcohol-resistant oral delivery systems for felodipine. Full article

The fast-disintegrating capsules rapidly disintegrate in various physiological environments, ensuring therapeutic efficacy. The formulation of plant-based capsules with balanced mechanical and fast disintegration characteristics continues to present technical challenges in pharmaceutical development. In this study, natural marine polysaccharides were utilized to achieve both rapid disintegration and excellent mechanical properties by combining κ-Carrageenan (κ-C) and ι-Carrageenan (ι-C). Additionally, the selection of KCl + NaCl mixed coagulants, along with the evaluation of their types, mass fractions, and ratios, enhanced the mechanical properties and transmittance of the capsules. FTIR analysis revealed that the membrane with a 5:5 κ-C/ι-C ratio formed hydrogen bonds, which were beneficial to its fast disintegration. SEM analysis revealed a dense microstructure in this formulation, contributing to its improved mechanical properties. Finally, this study hypothesizes that the disintegration behaviors of the capsules exhibited significant pH dependence, with ion exudation predominating in pH 1.2 and pH 7.0 media, while swelling dominated under pH 4.5 and pH 6.8 media. The prepared carrageenan blend-based capsules exhibited fast disintegration properties while maintaining excellent mechanical and barrier properties, thereby broadening the application of plant-based capsules in the field of medicine. Full article

The geological containment of high-level radioactive waste has become widely accepted among international organizations, and it has been adopted by many countries as part of their national nuclear waste disposal plan. The multi-barrier system, including the compacted bentonite blocks or pellets serving as human-made containment or buffer media, is the key component of high-level radioactive waste disposal, which contains a waste canister that isolates the nuclear waste from a human being geosphere for one million years. The bentonite clay surrounding the nuclear waste capsule is subjected to prolonged exposure to elevated temperatures because of the continuous decay of radioactivity. Long-term heating at high temperatures could change the buffers’ microstructural characteristics and physicochemical and hydromechanical properties, which can influence their self-sealing ability. This paper offers a comprehensive overview of the current understanding of thermal effects on bentonite-based buffer systems. The thermal impact on the microstructure, Atterberg limits, and swelling pressure of bentonite clay are intensely reviewed, and the findings are summarized. This review paper highlights new insights into the design of multi-layered containment approaches for high-level radioactive waste isolation. Full article

Chitosan–hydroxyapatite (CS-HAp) biocomposites, combining the biocompatibility and bioactivity of chitosan with the osteoconductive properties of hydroxyapatite, are emerging as promising candidates for tissue engineering applications. These materials consistently exhibit excellent cytocompatibility, with cell viability rates greater than 95% in MTT and Neutral Red Uptake assays, and minimal cytotoxicity, as demonstrated by low levels of cell death in DAPI and Trypan blue staining. More importantly, CS-HAp biocomposites modulate the immune environment by enhancing the expression of anti-inflammatory cytokines (IL-10 and IL-4) and the pro-inflammatory cytokine TGF-β, while avoiding significant increases in TNF-α, IL-6, or NF-κB expression in fibroblast cells exposed to HAC and HACF scaffolds. In an in vivo dermatitis model, these biocomposites reduced mast cell counts and plasma histamine levels and significantly decreased pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), JAK1/3, VEGF, and AnxA1 levels. Structurally, HACF scaffolds demonstrated larger average pore sizes (95 µm) compared to HAC scaffolds (74 µm), with porosities of 77.37 ± 2.4% and 65.26 ± 3.1%, respectively. These materials exhibited high swelling ability, equilibrium water content, and controlled degradation over a week in culture media. In addition to their immunomodulatory effects, CS-HAp composites promote essential cellular activities, such as attachment, proliferation, and differentiation, thereby supporting tissue integration and healing. Despite these promising findings, significant gaps remain in understanding the underlying mechanisms of immune modulation by CS-HAp biocomposites, and formulation-dependent variability raises concerns about reproducibility and clinical application. Therefore, a comprehensive review is essential to consolidate existing data, identify key knowledge gaps, and standardize the design of CS/HAp composites for broader clinical use, particularly in immunomodulatory and regenerative medicine contexts. Full article

The growth of plants highly depends on the soil’s water availability and properties. Hydrogels (HGs) have been used for decades to enhance soil water retention, whereas developing eco-friendly and sustainable HGs for agricultural applications is still necessary to ensure water and food security. In this study, renewable and cost-effective HGs were prepared from all-lignocellulose fibers of date palm biomass after carboxymethylation followed by citric acid (CA) crosslinking. HGs showed high equilibrium swelling capacity (EWC%), even in salty media, whereas purified HGs showed about 700–400 EWC% in deionized water. Further, HGs’ effect on germination was studied on Chico III tomato, mint, Basilico red, and chia seeds. The results revealed that HGs enhanced the soil properties, with taller and healthier plants observed in HG-amended soil. FTIR, thermal analysis, and microscope imaging were utilized to evaluate HGs’ and raw materials’ characteristics. The findings in this study support the idea that all-lignocellulose could be used for HG production without separation. Full article

Hyeonggaeyeongyo-tang (HGYGT), a traditional herbal formula, is used to treat inflammatory otorhinolaryngological diseases such as otitis media and sinusitis. In this study, we investigated the anti-inflammatory effects of HGYGT in LPS-stimulated RAW 264.7 cells (in vitro) and a carrageenan (CA)-induced rat paw edema model (in vivo). In LPS-stimulated RAW 264.7 cells, treatment with HGYGT (100 and 300 μg/mL) significantly reduced nitric oxide (NO) production by 24.5% and 51.3%, respectively (p < 0.05, p < 0.01). It also significantly suppressed the production of PGE2 (49.8%), IL-1β (42.7%), IL-6 (45.6%), and TNF-α (47.2%) at 300 μg/mL (p < 0.01). A Western blot analysis confirmed that HGYGT (300 μg/mL) significantly downregulated iNOS and COX-2 expression by 58.4% and 53.1%, respectively, while COX-1 remained unaffected. And HGYGT treatment at 300 μg/mL markedly inhibited NF-κB activation by 44.9% (p < 0.01). Furthermore, HGYGT selectively inhibited JNK phosphorylation by 46.7% (p < 0.01), without significantly affecting ERK1/2 or p38 MAPKs. In the CA-induced rat paw edema model, oral administration of HGYGT (1.0 g/kg) reduced paw swelling by 31.5% at 4 h post-injection (p < 0.01) and significantly decreased iNOS expression in inflamed paw tissues by 43.2% (p < 0.01). A histological analysis revealed that HGYGT (1.0 g/kg) reduced inflammatory cell infiltration by 39.6% in the affected tissue (p < 0.05), demonstrating its anti-inflammatory potential. Our findings demonstrate that HGYGT exerts anti-inflammatory effects by suppressing the JNK and NF-κB signaling pathways in LPS-stimulated RAW 264.7 cells, reducing the production of inflammatory mediators. Notably, HGYGT selectively inhibits COX-2 without affecting COX-1 and preferentially suppresses the JNK pathway. Moreover, its in vivo anti-inflammatory effects were confirmed through iNOS inhibition and histopathological analysis. These findings provide robust scientific evidence supporting the traditional use of HGYGT and its anti-inflammatory properties. Full article

Global challenges in agriculture, in terms of water and nutrient loss control, require new approaches to maintaining or even increasing crop production. Promising materials, such as superabsorbent hydrogels of hybrid types obtained from natural polymers grafted with synthetic polymers, represent a viable solution to solve these problems and maintain a clean environment. In view of this, two types of hydrogels based on sodium alginate, acrylic acid and polyethylene oxide obtained using 5.5 MeV electron-beam irradiation were subjected to degradation through burial in the soil. Swollen hydrogels in two types of water (distilled and tap) and two types of nutrient solutions (synthetic nutrient solution and 100% natural organic nutrient solution), with different pHs of 5.40, 6.05, 7.45 and 7.66, were buried in soil for 30 and 60 days and then extracted and analyzed in terms of their mass loss, swelling behavior and cross-linking structure. The highest mass losses after both 30 and 60 days were recorded for the hydrogels buried in soils whose humidity was maintained by watering them with the basic solutions (tap water and the organic nutrient solution). Structural modifications associated with the degradation process were highlighted by decreases in the cross-link densities and increases in the mesh sizes and swelling. These results were confirmed using FTIR and SEM techniques. Full article

In this study, a hydrogel material based on porcine gelatin and sodium alginate was synthesized for use as a dressing for chronic wound treatment. The hydrogels were covalently cross-linked using polyethylene glycol diglycidyl ether (PEGDE 500), and the interaction between the components was confirmed via FTIR. The properties of the resulting hydrogels were examined, including gel-fraction volume, swelling degree in different media, mechanical properties, pore size, cytotoxicity, and the ability to absorb and release analgesics (lidocaine, novocaine, sodium diclofenac). The hydrogel’s resistance to enzymatic action by protease was enhanced both through chemical cross-linking and physical interactions between gelatin and alginate. The absorption capacity of the hydrogels, reaching 90 g per dm² of the hydrogel dressing, indicates their potential for absorbing wound exudates. It was demonstrated that the antiseptic (chlorhexidine) contained in the structured gelatin–alginate hydrogels can be released into an infected substrate, resulting in a significant inhibition of pathogenic microorganisms (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Aspergillus niger). These results clearly demonstrate that the obtained hydrogel materials can serve as non-traumatic dressings for the treatment of chronic and/or infected wounds. Full article

Aripiprazole (ARZ) is an atypical antipsychotic drug used to treat a variety of mood and psychotic disorders, such as schizophrenia, bipolar disorder, major depressive disorder, autism, and Tourette’s syndrome. Although ARZ offers significant therapeutic benefits, its poor solubility in water requires the development of delivery systems aimed at improving the solubility and bioavailability of the drug. In this work, cryogels based on two natural products—agar and β-cyclodextrin (CD)—were developed and evaluated as a drug delivery system for ARZ. The cryogels were prepared by cryogenic treatment of aqueous solutions of agar and the β-CD/ARZ complex, followed by thawing. The main characteristics of the material, including gel fraction yield, swelling degree, pore volume, elastic properties, and morphology were studied in detail. The release of ARZ from composite cryogels was assessed in two media resembling the pH in stomach and intestine. The system exhibited a pH-dependent release of ARZ, with a slower rate in acidic media (pH 1.2) than in the neutral phosphate buffer (pH 6.8). Under in vitro conditions, the amount of released ARZ over 48 h reached 33%. Full article

The development of functional hydrogels is currently receiving great attention. In this study, a squid by-product, gelatin (SG)–acetic acid solution, was added to a commercial chitosan (CH)–acetic acid solution to develop an antioxidant hydrogel. The CH–SG mass ratios evaluated were 1:0, 2:1, and 1:2. Glutaraldehyde was used as cross linker. The effects of the SG addition to the hydrogel on different properties (physical in general, stability in aqueous media at pH 7.2, swelling, textural profile, and antioxidant) were evaluated. The interaction of CH and SG was established by scanning electron microscope microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). As a result, the addition of SG decreased the resistance to flow, hardness, chewiness, and stability, but increased the springiness, resilience, and antioxidant properties of CH hydrogels. The SEM analysis revealed that the CH-GS hydrogel showed a relatively more porous structure. FTIR and NMR analyses suggested a good compatibility of the components due mainly to an increased hydrogen bond formation. The present results suggest that CH could establish a valuable interaction with SG, so that a new hydrogel with enhanced textural and antioxidant properties would be produced, which would enable its potential application in biomedical and food industries. Full article

This article presents a simulation of a long-term retardation performance Mock-up test of the multi-field coupling of buffer materials, with the aim to study the thermo-hydro-mechanical (THM) processes occurring in the engineered barrier system of a high-level waste (HLW) repository. In view of the theory of mixtures and mechanics of continuous media, the coupled THM mathematical model of unsaturated buffer materials is established, considering heat transport and multiphase fluid flow. Using the buffer material Mock-up test of multi-field coupling as a model, the partial differential equation (PDE) module in the general finite element software COMSOL Multiphysics was developed by a second development stage. The dynamic response process of buffer material under the condition of THM coupling was numerically simulated, and the spatial distribution and variation law of suction, porosity, horizontal displacement, temperature and swelling pressure in the engineered barrier were investigated. The porosity of the buffer material under THM coupling was influenced by the swelling pressure and the suction. The welling pressure evolution of the buffer material may be influenced by the thermal expansion induced by high temperature and the swelling pressure generated by buffer material saturation. The evolution of the horizontal displacement of the heater used to simulate a container with radioactive waste was validated. This paper provides technical reference for the design and safety evaluation of underground laboratory barrier engineering in China. Full article

In this work, the effect of an acidic environment on the structure of composite samples based on ultra-high molecular weight polyethylene (UHMWPE) modified with mineral filler in the form of diabase (DB) is studied. The stability of samples was investigated in solutions of sulfuric (H₂SO₄) and hydrochloric (HCl) acids with concentrations of 10 vol% and 20 vol% at room temperature for 16 weeks. It was found that the introduction of 10 wt% DB into the UHMWPE matrix significantly increases the resistance of the composite sample to aggressive media, which is confirmed by the minimum degree of swelling compared to pure UHMWPE and composites with higher filler content. Scanning electron microscopy (SEM) demonstrated a uniform distribution of DB in the sample structure and the absence of defects such as agglomeration and cracks. The methods of infrared spectroscopy (IRS) and X-ray structural analysis (XRD) revealed a decrease in the degree of crystallinity of the samples after acid exposure, but no significant changes in the chemical structure of the materials were recorded, which confirms their resistance to chemical degradation. The best chemical resistance was demonstrated by composites containing 10 wt% DB, which is associated with the formation of a barrier structure preventing the diffusion of acids. The obtained results indicate the promising application of UHMWPE with DB filler to create samples resistant to aggressive media. Full article

Background/Objectives: This study is an attempt to reveal the potential of two types of interpenetrating polymer network (IPN) hydrogels based on poly(2-hydroxyethyl methacrylate) (PHEMA) and poly(N,N-dimethylacrylamide) (PDMAM). These IPNs were evaluated for their potential for dermal delivery of the hydrophobic drug dexamethasone (DEX). Methods: The two types of IPNs were analyzed for their rheological behavior, swelling characteristics, and drug-loading capacity with DEX. Drug release profiles were studied in Franz diffusion cells in PBS media. Finally, the cytotoxicity of the PHEMA/PDMAM-based IPNs was studied against T-cell lymphoma cells (HUT-78) and a normal murine fibroblast cell line (CCL-1). Results: The rheological properties of these hydrogels show suitable mechanical properties for dermal application, with G′ values of ~10 kPa. From the rheological data, the mesh size of these hydrogels was found to be influenced by the type of the IPN and its composition, varying between 6.5 and 50 nm. The loading capacity of both IPN types and DEX entrapment efficiency were highly influenced by the IPN’s composition. The loading capacity of the IPNs can reach ~3.5%, with a DEX entrapment efficiency of ~35%. The PHEMA/PDMAM IPNs demonstrate an extended release profile with up to ~95% DEX released in 24 h, while PDMAM/PHEMA IPNs release no more than ~25% DEX in 24 h. The drug release profiles follow either non-Fickian diffusion (n~0.6) or case-II transport (n~0.9–1), depending on the IPN’s composition. The PHEMA/PDMAM-based materials were found to be non-cytotoxic against HUT-78 and CCL-1 cells. Conclusions: The study reveals that the IPNs of PHEMA and PDMAM appear to be suitable platforms for dermal delivery of dexamethasone as they have appropriate mechanical properties, providing tools to control drug loading and release, and they are biocompatible with human skin cells. Full article

This study aimed to evaluate the influence of indirect-plasma-treated water (IPTW) in the preparation of hydrogels. Three commonly used natural, biodegradable polymers with the ability to form gels were selected: gelatin, carrageenan, and sodium alginate. The pH, gelling temperature, texture profile, swelling degree, and color of hydrogels were evaluated, and the polymers were subjected to Fourier-transform infrared (FTIR) spectroscopy. The morphology of the hydrogels was investigated using Scanning Electron Microscopy (SEM). Additionally, the physiochemical properties of the water media, which were distilled water (DW) and IPTW, were analyzed. The results indicated that the gels prepared using IPTW were characterized by a lower pH, higher hardness and lower gelation temperature. After 48 h of swelling ratio (SR) testing, gelatin and alginate hydrogels made with IPTW were characterized by lower SR, while an inverse relationship was found in the case of SR of carrageenan gels. The FTIR analysis confirmed changes in the water binding ability. The use of IPTW also significantly affected the microstructure of the tested materials. A statistically significant change in the color of IPTW gel samples was also noted. The results showed that IPTW induces physicochemical changes in hydrogels, which can lead to the enhancement of their practical applications. Full article

Taking into account the trends in the field of green chemistry and the desire to use natural materials in biomedical applications, (bio)polyelectrolyte complexes ((bio)PECs) based on a mixture of chitosan and gelatin seem to be relevant systems. Using the approach of self-assembly from the dispersion of the coacervate phase of a (bio)PEC at different ratios of ionized functional groups of chitosan and gelatin (z), hydrogels with increased resistance to mechanical deformations and resorption in liquid media were obtained in this work in comparison to a hydrogel from gelatin. It was found that at z ≥ 1 a four-fold increase in the elastic modulus of the hydrogel occurred in comparison to a hydrogel based on gelatin. It was shown that hydrogels at z ≈ 1 had an increased sorption capacity and water sorption rate, as well as increased resistance to the in vitro model environment of phosphate-buffered saline (PBS) solution containing lysozyme at 37 °C. It was also shown that in PBS and simulated gastric fluid (SGF) solutions, the effect of the polyelectrolyte swelling of the hydrogels was significantly suppressed; however, at z ≥ 1, the (bio)PEC hydrogels had increased stability compared to the samples at z < 1 and based on gelatin. Full article