Search Results (3,651)

The rational design of mixed micellar systems has emerged as a cornerstone of modern nanomedicine, offering unprecedented control over the solubility and bioavailability of challenging therapeutic agents. This review provides a comprehensive analysis of the physicochemical principles governing the assembly of amphiphilic drugs and surfactants into synergistic nanostructures. By articulating the transition from traditional guest/host solubilization to “drug-as-component” models, we highlight the critical role of molecular interactions in achieving therapeutic precision. It further outlines the experimental methodologies used to investigate these systems and elucidates how they enhance the solubility, stability, and bioavailability of poorly water-soluble drugs. Special emphasis is placed on the practical applications of synergy in reducing systemic toxicity and optimizing drug release kinetics, providing a roadmap for the development of next-generation nano-pharmaceuticals. The functionality of these systems is significantly influenced by the molecular interactions among their constituents; thus, quantitative analysis of these interactions might enhance the formulation of more effective pharmaceuticals. This review outlines the key physicochemical principles of mixed micelle formation, including thermodynamics and synergistic interactions of amphiphiles, while emphasizing their relevance in current research and practical pharmaceutical applications. Various experimental methods, such as surface tension measurement, conductometric and calorimetric tests, and spectroscopic techniques, are compared in terms of their conditions of application and performance in understanding micelle formation and micelle structure. We clearly point out that the interpretation and evaluation of the properties of colloidal systems containing drug molecules solubilized by mixed micelles and an amphiphilic drug incorporated into micelles must be discussed and evaluated separately. Understanding the limitations and characteristics of the physical/chemical principles applied is essential for the rational design of mixed micelle carriers tailored to specific therapeutic needs. Full article

Modulating the physical crosslink architecture of gelatin methacryloyl (GelMA) hydrogels without altering total polymer concentration or introducing exogenous components remains a central challenge in biomaterial design. Here, we present a source blending strategy in which porcine skin gelatin (PG) and salmon skin gelatin (SG), two gelatins with markedly different proline and hydroxyproline contents, are combined at seven compositional ratios (PG weight fractions 0–1.0) and subsequently functionalized to GelMA under standardized conditions (8% v/v methacrylic anhydride, 60 °C, 3 h). Near-complete degrees of substitution (95–98%) were achieved across all formulations, as confirmed by both TNBS and ¹H-NMR analyses. In the parent gelatin mixtures, increasing PG fraction progressively increased viscosity, elastic modulus (G′), gelation temperature (Tgel), and compression modulus at 4 °C, with DSC revealing independent SG (0–15 °C) and PG (20–40 °C) endothermic transitions that suggest partial hindrance of PG triple-helix formation by high SG fractions. These composition-dependent trends were preserved after functionalization to GelMA, albeit with attenuated physical crosslinking due to steric impairment by the methacrylate groups. Photocrosslinked GelMA hydrogels fabricated after pre-incubation at 4 °C exhibited systematically higher compression moduli and lower swelling degrees with increasing PG content, demonstrating that the PG/SG ratio provides an effective means for independently tuning hydrogel mechanics and mesh architecture. In vitro release assays using Rhodamine 6G further demonstrated that pre-incubation at 4 °C prior to photocrosslinking effectively modulates transport kinetics in SG-PG GelMA hydrogels. This strategy delayed characteristic release times and constrained Weibull shape parameters to the anomalous-transport regime (0.75 < β < 1), where diffusion is governed by network chain relaxation. This effect was most pronounced in the 0.4SG:0.6PG formulation, where lower SG content permitted unhindered triple-helix formation, as corroborated by DSC and compression studies. Ultimately, adjusting the pre-incubation temperature and gelatin source combination provides a straightforward, processing-additive-free strategy to achieve programmable release profiles via controlled matrix tortuosity. Full article

A computational fluid dynamics (CFD) analysis is conducted to systematically investigate heat transfer enhancement in tubes fitted with grooved twisted tapes and to identify the groove geometry that provides the best thermo-hydraulic performance. Three grooved twisted tape configurations—circular-grooved twisted tapes (CGTT), rectangular-grooved twisted tapes (RGTT), and triangular-grooved twisted tapes (TGTT)—are evaluated and compared with a smooth tube and a conventional twisted tape over a Reynolds number range of 5000–20,000 under isothermal wall conditions. The grooved twisted tapes enhance heat transfer through the combined effects of swirl-induced secondary flows and groove-generated flow disturbances, which intensify turbulent mixing and reduce the thickness of the thermal boundary layer. Compared with the plain tube, the grooved configurations increase the Nusselt number by 1.472–1.98 times while increasing the friction factor by 3.21–3.58 times. Relative to the conventional twisted tape, the grooved designs provide an additional 8.0–12.1% enhancement in heat transfer with only a marginal increase of 0.2–1.5% in friction factor. The thermodynamic analysis indicates that the CGTT configuration exhibits the lowest entropy generation rate and exergy loss throughout the investigated Reynolds number range. In particular, the CGTT achieves a Bejan number of 0.999841 at Re = 5000, demonstrating an excellent balance between heat transfer enhancement and frictional losses. Furthermore, the CGTT attains the highest thermal performance factor (TPF) of 1.294 at Re = 5000 and maintains TPF > 1.0 over the entire Reynolds number range. The overall performance ranking is consistently established as CGTT > TGTT > RGTT based on comprehensive analyses of velocity fields, streamline patterns, turbulent kinetic energy distributions, temperature contours, and thermodynamic characteristics. Although the present study identifies the circular-groove configuration as the optimal design for a twist ratio (y/W) of 3.0, further parametric investigations involving variations in twist ratio, groove dimensions, and groove pitch are required to develop generalized design guidelines. Full article

High-temperature temporary sealing operations require liquid plug materials that can be placed as low-viscosity precursors, converted into mechanically stable networks under reservoir temperature, and subsequently removed after service. Existing epoxy-based sealing systems generally provide high post-curing strength, but the coordination among pumpability, thermally triggered curing, and post-service degradability remains insufficiently addressed. In this work, an epoxidized soybean oil (ESO)-modified epoxy–anhydride liquid plug was designed to regulate these sequential stages within a single material system. The precursor formulation, rheological transition, curing kinetics, mechanical response, network structure, and degradation behavior were evaluated using viscosity monitoring, curing-time tests, DSC, compression testing, DMA, gel fraction and swelling measurements, FTIR, and high-temperature degradation experiments. The optimized precursor exhibited an initial viscosity of 65.4 ± 2.1 mPa·s, remaining below the pumpability threshold of 100 mPa·s before curing. Its curing time was adjustable within 1–10 h at 120–140 °C through temperature and initiator regulation. ESO incorporation produced a non-monotonic mechanical response, with the optimized network reaching a compressive strength of 112.5 ± 3.5 MPa and an elastic modulus of 142.50 ± 5.26 MPa. FTIR and thermal–mechanical analyses supported the formation of an ester-rich epoxy–anhydride network containing both rigid epoxy-derived segments and ESO-derived flexible chains. In the post-service stage, degradation was strongly temperature dependent, with the characteristic unsealing time decreasing from 84 h at 120 °C to 24 h at 130 °C and 18 h at 140 °C. The combined results define a coupled curing–degradation window in which pumpable placement, thermal network formation, load-bearing sealing, and controlled unsealing are temporally separated but structurally connected. Full article

The performance of drug-loaded electrospun nanofibres is governed not only by drug content but also by the spatial distribution of the drug within the fibre matrix, which determines release kinetics and biological response. Here, we demonstrate that dose-dependent surface crystallisation of dexamethasone (DEX) in electrospun polycaprolactone (PCL)/gelatin nanofibres controls drug release behaviour and subsequent macrophage-mediated inflammation. Nanofibre mats containing 0, 1, and 2 wt% DEX (PG0, PG1, PG2) were fabricated and systematically characterised. Scanning electron microscopy revealed a change from homogeneous fibres (PG0) to surface-decorated crystalline domains with increasing drug loading, which indicates a supersaturation-driven phase separation during electrospinning. This morphological evolution directly governs the transport behaviour: PG2 exhibits a pronounced burst release due to surface-localised drug, whereas PG1 shows a balanced release profile with both surface-accessible and matrix-embedded drug fractions. Release characteristics result in different biological outcomes. PG1 and PG2 strongly inhibit pro-inflammatory cytokines (TNF-α and IL-6) in LPS-stimulated macrophages (~70–75% reduction), confirming retained drug bioactivity. However, higher drug loading (PG2) leads to lower fibroblast viability and compromised mechanical integrity. Importantly, PG1 shows a desirable balance of controlled drug release, cytocompatibility (>90% viability) and mechanical performance (~8 MPa) with effective anti-inflammatory activity. Degradation studies also show controlled structural evolution without destabilisation upon pH change, demonstrating suitability for wound environments. These results reveal surface crystallisation as an important design parameter for electrospun drug delivery systems and demonstrate that optimal therapeutic performance is controlled by intermediate drug loading, not maximum loading, providing a mechanistic framework for the rational design of immunomodulatory wound dressings. Full article

The successful application of extrusion-based 3D-printed geopolymer mortars largely depends on precursor chemistry, activator composition, mixture proportions, and fresh-state behavior, which is highly sensitive to time-dependent structural build-up. This review examines the relationships among mix design, geopolymerization chemistry, rheological properties, and printability requirements for 3D-printed geopolymer mortars. Particular emphasis is placed on the effects of precursor type, alkaline activator characteristics, liquid-to-solid ratio, additives, and fibers on flowability, yield stress, viscosity, extrudability, buildability, shape retention, and interlayer bonding. The review further discusses how geopolymerization kinetics influence the evolution of fresh-state properties, the printable time window, and the transition from extrusion to structural stability. In addition, early-age performance is evaluated in terms of setting behavior, green strength development, and layer-interface integrity. Current challenges, including the lack of standardized test methods, limited comparability among published studies, and the complex coupling between material design and process parameters, are also highlighted. Finally, the review identifies key research gaps and proposes future directions for developing robust, printable, and sustainable geopolymer mortar systems for additive manufacturing in construction. Full article

Trimethylamine (TMA), a characteristic volatile biogenic amine generated during aquatic product spoilage, has a concentration that quantitatively reflects product freshness. Therefore, developing a rapid and accurate method for TMA detection is important for food safety control. Herein, this study synthesized high-performance hollow SnO₂ nanospheres via a hydrothermal method, aiming to develop a rapid, non-destructive gas sensor for TMA detection and evaluate its feasibility for assessing aquatic product freshness. The material exhibited a high response (Ra/Rg = 10.5@100 ppm), rapid response-recovery kinetics (10 s/20 s), and good selectivity. These properties were attributed to the high specific surface area, efficient gas diffusion channels, and abundant active sites provided by the hollow structure, which enhances the sensor’s response rate. Ultraviolet–visible diffuse reflectance spectroscopy further showed that the hollow structure narrows the bandgap of SnO₂, which may facilitate electron transfer and contribute to the enhanced response to TMA. In practical applications, a MEMS sensor based on SnO₂ hollow nanospheres successfully detected TMA concentration changes from sea bass during 0–8 days of refrigerated storage, demonstrating its potential reliability for rapid freshness assessment of aquatic products and providing a technological route for quality evaluation. Full article

Mesenchymal progenitor cells (MPCs) play a significant role in articular cartilage homeostasis and regeneration. Yet, the functional dynamics and molecular characteristics of MPCs may differ significantly across various pathological conditions. Hence, this study comprehensively investigates the biological and molecular characteristics of MPCs isolated from articular cartilage of patients with osteoarthritis (OA) and rheumatoid arthritis (RA), aiming to uncover disease-specific differences that could offer insights into targeted regenerative therapies. Using flow cytometry, gene expression analysis, and in vitro differentiation assays, we assessed the phenotype, growth potential, senescence, cytogenetic instability, and chondrogenic potential to delineate molecular pathways uniquely active in each disease context. Phenotypically, both OA and RA-MPCs retained markers of mesenchymal stem cells (MSCs), but OA-derived MPCs exhibited higher fold expression of progenitor markers (OCT-4, NANOG, SOX-2, and SSEA-4), suggesting a more activated state. Functionally, OA-MPCs demonstrated increased growth kinetics (higher proliferation rate and decreased population doubling time) with a significant shift towards adipogenic lineages (increased fold expression of LPL, AP2, and PPAR-γ). However, there were no differences in the osteogenic and chondrogenic potential. Gene expression analysis revealed upregulation of genes involved in extracellular matrix production and cartilage development (COL2-α1, ACAN, FGFR3, TGF-β3, ANXA6, CNTN1, MATN1, TGF-β1, VIM, and SOX9) in 3D cultures compared with 2D or monolayer cultures. Collectively, these findings demonstrate that, while multipotent MPCs are present in both OA and RA articular cartilage, they can exhibit fundamentally altered biological behaviors and molecular signatures reflective of the local disease microenvironment. Understanding these differences is critical for optimizing cell-based therapeutic strategies tailored to each condition and may facilitate the development of novel interventions targeting endogenous progenitor cells for cartilage repair. Full article

Water-soluble viscosity-modifying admixtures (VMAs) were initially introduced into cementitious materials to enhance cohesion, stability and resistance to bleeding and segregation. With the development of self-compacting concrete, underwater concrete, grouting materials and 3D-printed cementitious materials, VMAs have become increasingly important for regulating rheological behavior, workability retention, shape retention and construction processability. Recent studies further indicate that VMAs can affect not only fresh-state properties, but also hydration kinetics, early-age microstructure evolution, mechanical performance, transport behavior and long-term durability. This review systematically summarizes the types, action mechanisms, and performance effects of water-soluble VMAs in cementitious materials. Particular emphasis is placed on the relationships among the molecular structure, liquid phase viscosity enhancement, particle adsorption and bridging, polymer-chain entanglement, ion-responsiveness, admixture compatibility, and microstructure evolution. The review shows that the effects of VMAs are not governed solely by admixture type or dosage, but depend strongly on molecular mass, functional groups, substituent composition, charge characteristics, binder chemistry, and the pore solution environment. Finally, current research gaps and future directions are discussed, including quantitative structure–mechanism–performance relationships, applicability in low-carbon binders, service-life prediction, and application-oriented VMA design. Full article

Foam injection moulding (FIM) enables lightweight thermoplastic parts, but current process simulations do not resolve microstructure formation. This work presents a micro-scale CFD framework for FIM that captures gas–melt interaction and bubble morphology. A two-phase, compressible volume-of-fluid solver (OpenFOAM) with surface tension and viscoelastic Phan–Thien–Tanner rheology is coupled to a nucleation pre-processor based on classical nucleation theory, which places bubbles stochastically using macro-scale pressure and temperature histories. The approach was demonstrated on a plate geometry using a 2D through-thickness section to investigate bubble nucleation, deformation, coalescence, and interaction under realistic process conditions. The simulations reproduced characteristic morphology trends across the thickness. In particular, the predicted aspect ratio and orientation show the expected skin–core behaviour and agree qualitatively with experimental observations. These results demonstrate that the framework can describe morphology development beyond simplified spherical-cell assumptions and provides a proof of concept for multiscale coupling between macro-scale process conditions and micro-scale foam structure evolution. A simplified surrogate growth representation was used to enable bubble expansion; however, a physically based mass-transfer model is required for quantitatively accurate growth kinetics. Full article

This study investigated the mechanism underlying how the integration of chemical fertilizer and maize straw-derived organic amendments affects different potassium (K) pools, K saturation, K fixation characteristics, and non-exchangeable potassium (NEK) release kinetics in black soil. A field experiment involving five treatments was conducted: no fertilizer (CK), chemical fertilizer alone (NPK), chemical fertilizer plus maize straw (NPK+ST), chemical fertilizer plus straw compost (NPK+CP), and chemical fertilizer plus straw biochar (NPK+BR). The findings demonstrated remarkably increased contents of different K pools and K saturation in the black soil following the combined application of straw-derived organic amendments, with NPK+CP exhibiting the most significant effect. Exogenous K fixation simulation tests indicated that the amount of K fixation in the black soil increased with the incorporation of exogenous K, while the fixation rate showed the opposite trend. The quadratic regression model well fitted the relationship between the amount of K fixation and the addition of exogenous K; the treatments were ranked according to the soil K fixation capacity as follows: CK > NPK > NPK+BR > NPK+ST > NPK+CP. The simplified Elovich model well fitted the NEK release process in the black soil under different treatments. Significant differences in total cumulative NEK release and apparent release rate coefficients were observed among the treatments, which showed an identical trend: NPK+CP > NPK+BR > NPK+ST > NPK > CK. The application of straw-derived organic amendments could effectively reduce the K fixation capacity of black soil and promote NEK release. In this study, chemical fertilizer combined with straw compost was the optimal measure for improving black soil’s potassium availability. Full article

Concrete contributes significantly to global CO₂ emissions due to high energy demand for cement production. This research integrates multiple advanced ensemble ML-based prediction models by combining experimental evaluation, explainable framework, and life cycle sustainability analysis for SCM (supplementary cementitious materials)-incorporated concrete mixtures. A comprehensive experimental program was conducted to evaluate the compressive and tensile strength of concrete revealing that the hybrid mix of GF4 with a 40% replacement level of cement with fly ash (FA) and ground granulated blast furnace slag (GGBFS) exhibited optimum synergistic performance due to balanced hydration kinetics and improved microstructure characteristics. For computational model development, a k-fold cross validation technique was deployed to evaluate robustness across multiple data partitions and to control overfitting in models. Model performance was assessed through multiple metrics including R², RMSE, and MAE with particular emphasis on the gap between training and testing performance. The best performing model was optimized using Particle Swarm Optimization (PSO) and Bayesian Optimization (BO) techniques providing an additional safeguard against overfitting. Shapley Additive Explanation (SHAP) interpretation revealed w/b ratio and curing age as key parameters for compressive strength, while fine aggregate content and curing age influenced tensile strength. For compressive strength, XGBoost model performed well with an R² value of 0.879 which was increased to 0.918 with the PSO optimization technique. For tensile strength, the Gradient Boosting model was selected with an R² value of 0.840 which was optimized to 0.879 after the PSO optimization technique. Moreover, life cycle assessment was performed to evaluate the environmental impacts in terms of embodied carbon and energy associated with concrete mixes. The hybrid GF4 mix demonstrated a 36% reduction in embodied carbon compared to the control mix, indicating strong potential for low carbon concrete applications. This integrated research contributes to the advancement of green construction practices and supports global efforts to reduce atmospheric impacts through the circular use of industrial byproducts. Full article

The global transition from petrochemical to sustainable bio-based plastics has been strongly supported by electrospinning (ES), a versatile nanotechnology enabling the fabrication of ultrathin fibers with multifunctional properties. The solution ES process alongside the uniform fibers, a characteristic “beads-on-string” morphology, consisting of alternating cylindrical and spindle-like segments, is frequently observed. Once considered undesirable, these structures are now recognized as functional fibrous architectures with enhanced properties. This work explores the valorization of beaded fibers through combined experimental characterization and modeling, aiming to evaluate the impact of beading on drug diffusion and delivery performance. Poly(3-hydroxybutyrate) (PHB) was selected as the model biopolyester and dipyridamole (DPD) as the model drug. Ultrathin fibers were fabricated using the laboratory electrospinning device, EFV-1 (ICP, Moscow, Russia). The distance between the capillary nozzle and the anodic collector was set to 180 mm, with the capillary tip radius equal to 0.35 mm, and applied voltage between the electrodes was kept constant at 18 kV. Drug release profiles were obtained by simulating DPD diffusion in ellipsoidal (beads) and cylindrical fiber domains. Ultrathin fibers were fabricated by solution electrospinning under environmental conditions (at ambient temperature, 50% relative humidity). Morphology was analyzed via SEM, thermal properties via DSC, and structure via FTIR spectroscopy at different temperatures, including the melting point (~170 °C). Drug release kinetics were monitored using a UV-Vis spectroscopy. The impact of DPD diffusion within the ellipsoidal and cylindrical constituents of polymer filaments was considered to modulate release profiles for the development of innovative pharmaceutical platforms. Diffusion controlled drug release was computationally modeled using a specially designed simulation program, in good agreement with experimental data. The results demonstrate that morphological parameters significantly affect diffusion and release kinetics. The controlled exploitation of bead-on-string architectures may enable the design of electrospun materials with tunable absorption of pollutant filtration, mechanical performance, and flexibility in drug release profiles, for sustainable biopolymers like PHB. Full article

Background: Existing therapies for xerostomia are primarily symptomatic, providing temporary mucosal hydration without addressing underlying pathological changes in the oral cavity. In this context, medicated chewing gums containing ascorbic acid and lysozyme hydrochloride offer a promising approach, combining antimicrobial, antioxidant, and trophic effects with physiological salivary stimulation and prolonged local delivery. Methods: For the development of compressed chewing gum formulation, the physicochemical (particle size distribution, moisture absorption capacity, and microscopic characteristics) and technological (flowability, angle of repose, bulk and tapped density, Carr’s index (CI), and Hausner ratio (HR)) properties of the active substances and their formulations with excipients were evaluated. Pharmacological activity was assessed in an atropine-induced xerostomia rat model. Results: The physical mixture of all components showed inferior flow properties compared with the formulation containing pre-granulated lysozyme hydrochloride, as evidenced by higher Carr’s index and Hausner ratio values (CI = 17, HR = 1.20 vs. CI = 13, HR = 1.14), indicating improved processability after pre-granulation. The effect of relative humidity during formulation was also assessed, with an optimal level of 40% required to ensure process stability due to the hygroscopic nature of the components. Based on these data, technological approaches ensuring processability were established, including wet pre-granulation of lysozyme hydrochloride and premixing of ascorbic acid to reduce oxidation risk. These approaches resulted in an optimized compression mass with excellent flowability (CI = 8, HR = 1.09), suitable for the preparation of medicated chewing gum. An optimal compression force (7 kN) ensured suitable rheological and textural properties, resulting in rapid and nearly complete release of the active ingredients from the medicated chewing gum, consistent with kinetic analysis. In vivo studies using an atropine-induced xerostomia rat model demonstrated that the combination of ascorbic acid and lysozyme hydrochloride significantly increased salivary secretion (2.17-fold vs. control pathology group) and reduced salivary gland mass coefficients (by 13–18% compared with the control pathology group and groups receiving individual active ingredients), alongside improvement of oxidative stress markers, including a reduction in TBA-reactants (by 51.6%) and an increase in catalase activity (by 51.0%). Conclusions: The developed medicated chewing gum showed favorable technological properties, efficient release of active ingredients, and anti-xerostomic activity in vivo, indicating its potential for xerostomia relief and oral health support. Full article

Direct emission of low-concentration methane not only aggravates global warming but also causes serious energy waste. Catalytic combustion is considered an effective strategy for methane abatement because it enables methane oxidation at relatively low temperatures. In this work, a series of Mn–Ce–Cu/γ-Al₂O₃ catalysts with different nominal Mn/Ce ratios were prepared by the incipient wetness impregnation method and applied to low-concentration methane catalytic combustion. The results showed that Mn–Ce co-modification significantly improved the activity of Cu/γ-Al₂O₃ catalysts, and the catalytic performance strongly depended on the Mn/Ce ratio. Among all samples, 7Mn-3Ce-10Cu exhibited the best activity, with the temperatures required for 10%, 50% and 90% methane conversion (T₁₀, T₅₀ and T₉₀) of 380.8, 427.3 and 478.7 °C, respectively. Apparent activation energy (E_a) analysis further showed that 7Mn-3Ce-10Cu possessed the lowest E_a value of 83.81 kJ mol⁻¹, indicating that the optimized Mn/Ce ratio effectively lowered the apparent kinetic barrier for methane oxidation. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nitrogen (N₂) adsorption–desorption results suggested that Mn–Ce co-modification changed the phase composition, improved the dispersion state of active oxide species and generated a more favorable pore structure for reactant diffusion. Oxygen temperature-programmed desorption (O₂-TPD) and X-ray photoelectron spectroscopy (XPS) results further indicated that the enhanced activity of 7Mn-3Ce-10Cu was closely associated with improved oxygen desorption behavior, a higher proportion of surface oxygen species and favorable surface redox characteristics of Cu, Mn and Ce species. Moreover, 7Mn-3Ce-10Cu maintained methane conversion above 90% during a 50 h stability test at 500 °C, and the inhibition caused by 5% H₂O was partially reversible. These results demonstrate that Mn–Ce co-modification is an effective strategy for improving low-cost Cu-based catalysts for low-concentration methane combustion. Full article