Search Results (401)

Leishmaniasis is an infectious disease common in tropical and subtropical regions worldwide. This study aimed to develop a topical meglumine antimoniate gel (MA-gel) for the treatment of cutaneous leishmaniasis. The MA-gel was characterized in terms of morphology, pH, swelling, porosity, rheology, and thermal properties by differential scanning calorimetry (DSC). Biopharmaceutical evaluation included in vitro drug release and ex vivo skin permeation. Safety was evaluated through biomechanical skin property measurements and cytotoxicity in HaCaT and RAW 267 cells. Leishmanicidal activity was tested against promastigotes and amastigotes of Leishmania infantum, and in silico studies were conducted to explore possible mechanisms of action. The composition of the MA-gel included 30% MA, 20% Pluronic^® F127 (P407), and 50% water. Scanning electron microscopy revealed a sponge-like and porous internal structure of the MA-gel. This formula exhibited a pH of 5.45, swelling at approximately 12 min, and a porosity of 85.07%. The DSC showed that there was no incompatibility between MA and P407. Drug release followed a first-order kinetic profile, with 22.11 µg/g/cm² of the drug retained in the skin and no permeation into the receptor compartment. The MA-gel showed no microbial growth, no cytotoxicity in keratinocytes, and no skin damage. The IC₅₀ for promastigotes and amastigotes of L. infantum were 3.56 and 23.11 µg/mL, respectively. In silico studies suggested that MA could act on three potential therapeutic targets according to its binding mode. The MA-gel demonstrated promising physicochemical, safety, and antiparasitic properties, supporting its potential as a topical treatment for cutaneous leishmaniasis. Full article

A metal-ion-free method was developed to prepare κ-carrageenan/cellulose hydrogel beads for efficient cationic dye removal. The beads were fabricated using a mixture of 1-ethyl-3-methylimidazolium acetate and N,N-dimethylformamide as the solvent system, followed by aqueous ethanol-induced phase separation. This process eliminated the need for metal-ion crosslinkers, which typically neutralize anionic sulfate groups in κ-carrageenan, thereby preserving a high density of accessible binding sites. The resulting beads formed robust interpenetrating polymer networks. The initial swelling ratio reached up to 28.3 g/g, and even after drying, the adsorption capacity remained over 50% of the original. The maximum adsorption capacity for crystal violet was 241 mg/g, increasing proportionally with κ-carrageenan content due to the higher surface concentration of anionic sulfate groups. Kinetic and isotherm analyses revealed pseudo-second-order and Langmuir-type monolayer adsorption, respectively, while thermodynamic parameters indicated that the process was spontaneous and exothermic. The beads retained structural integrity and adsorption performance across pH 3–9 and maintained over 90% of their capacity after five reuse cycles. These findings demonstrate that κ-carrageenan/cellulose hydrogel beads prepared via a metal-ion-free strategy offer a sustainable and effective platform for cationic dye removal from wastewater, with potential for heavy metal ion adsorption. Full article

Chitosan hydrogels have gained attention in biomedical and pharmaceutical research due to their biocompatibility, biodegradability, and tunable properties. To enhance mechanical strength and to control swelling and degradation, chitosan is often cross-linked with either bio-based (e.g., genipin) or synthetic (e.g., glutaraldehyde) agents. A comprehensive understanding of the degradation mechanisms of cross-linked chitosan hydrogels is essential, as it directly impacts performance optimization, regulatory compliance, and their integration into personalized medicine. Despite extensive studies, the fundamental mechanisms governing hydrogel degradation remain partially understood. In this work, we introduce a general data-driven framework based on symbolic regression to elucidate the degradation kinetics of hydrogels. Using genipin-cross-linked chitosan hydrogels as a model system, we analyze experimental degradation data to identify governing kinetic laws. Our results suggest that degradation proceeds primarily via a surface-mediated mechanism. The proposed approach provides a robust and interpretable method for uncovering mechanistic insights and is broadly applicable to other hydrogel systems. Full article

This study investigated the impact of increased extraplatelet content on the tissue regenerative capacity of platelet-rich plasma (PRP)-derived fibrin scaffolds. Comparative analyses were performed between a “balanced protein-concentrate plasma” (BPCP) and a standard PRP (sPRP), focusing on platelet and fibrinogen content, scaffold microstructure, and functional performance. Growth factor (GF) release kinetics from the scaffolds were quantified via ELISA over 10 days, while scaffold biomechanics were evaluated through rheological testing, indentation, energy dissipation, adhesion, and assessments of coagulation dynamics, biodegradation, swelling, and retraction. Microstructural analysis was conducted using scanning electron microscopy (SEM), with fiber diameter and porosity measurements. The results demonstrated that BPCP scaffolds released significantly higher amounts of GFs and total protein, especially beyond 24 h (* p < 0.05). Despite a delayed coagulation process (** p < 0.01), BPCP scaffolds exhibited superior structural integrity and cushioning behavior (* p < 0.05). SEM revealed thicker fibers in BPCP scaffolds (**** p < 0.0001), while adhesion and biodegradation remained unaffected. Notably, BPCP scaffolds showed reduced retraction after 24 h and maintained their shape stability over two weeks without significant swelling. These findings indicate that enhancing the extraplatelet content in PRP formulations can optimize fibrin scaffold performance. Further preclinical and clinical studies are warranted to evaluate the therapeutic efficacy of BPCP-derived scaffolds in regenerative medicine. Full article

This study presents novel skin-compatible biomaterials based on guar gum and dextran sulfate matrices, incorporating softwood lignin, lignin esterified with aspartic acid, and Rosa canina extract. The materials were prepared via casting and evaluated for physicochemical, mechanical, and biological properties. Spectroscopic analyses confirmed successful lignin esterification, with new carbonyl and amide peaks and a nitrogen signal (3.83%) detected. Rosa canina extract enhanced the Young’s modulus from 1.42 MPa to 3.18 MPa and reduced elongation at break from 34.88 mm to 25.19 mm. The combination of esterified lignin and Rosa canina showed the greatest mechanical reinforcement (3.74 MPa modulus, 23.78 mm elongation). Swelling capacity decreased from 0.40 to 0.23 g water/g material and followed pseudo-second-order kinetics (R² = 0.991–0.998). The release of Rosa canina bioactives followed the Makoid–Banakar model, indicating a transition from rapid to sustained release. All formulations exhibited anti-inflammatory activity with over 45% protein denaturation inhibition, peaking at 61.58% for the Rosa canina-only sample. In vitro biocompatibility assays demonstrated over 80% cell viability, confirming the potential of these biomaterials for dermal applications. Full article

Electroless nickel deposition (ELD) on polymer substrates enables the fabrication of flexible, conductive fibres for wearable and functional textiles. However, achieving uniform, low-defect coatings on synthetic fibres such as nylon-6,6 remains challenging due to their chemical inertness, hydrophobicity, and poor interfacial compatibility with metal coatings. This study presents a solvent-assisted approach using dimethyl sulfoxide (DMSO) in a conventional aqueous ELD bath to control both polymer–metal interfacial chemistry and nickel coating microstructure. The modified surface supports dense catalytic sites, triggering spatially uniform Ni nucleation. The combination of scanning electron microscopy and transmission electron microscopy confirms the difference in coarse grains with fully aqueous baths to a nanocrystalline shell with DMSO-modified baths. This refined microstructure relieves residual stress and anchors firmly to the swollen polymer, delivering +7 °C higher onset decomposition temperature and 45% lower creep strain at 50 °C compared with aqueous controls. The fabric strain sensor fabricated by 1 wt.% DMSO-modified ELD shows a remarkable sensitivity against strain, demonstrating a 1400% resistance change under 200% stain. Electrochemical impedance and polarisation tests confirm a two-fold rise in charge transfer resistance and negligible corrosion current drift after accelerated ageing. By clarifying how a polar aprotic co-solvent couples polymer swelling with metal growth kinetics, the study introduces a scalable strategy for tuning polymer–metal interfaces and advances solvent-assisted ELD as a route to mechanically robust, thermally stable, and corrosion-resistant conductive textiles. Full article

Functional fabrics embedded with active materials that can be released in a controlled manner upon external triggering have been explored for biomedical and cosmetic applications. This study introduces a method for the fabrication of nonwoven fabrics coated with crosslinked polyvinyl alcohol (PVA) for in situ encapsulation and controlled release of hydrophilic active agent, allantoin. Two types of crosslinked coatings were examined using citric acid (CA) or polyacrylic acid (PAA) as crosslinkers. Based on gel content, differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) analyses PVA:CA coatings exhibited a higher crosslinking density compared to PVA:PAA systems. Swelling behavior was measured at 62% after 30 min for PVA:PAA 7:3 films and 36% after 60 min for PVA:CA 7:3 crosslinked films. The release of allantoin from the coated fabrics was influenced by the coating thickness (250–330 µm), the formulation viscosity (8–250 cP), allantoin content (1.2–4.2 mg) and the molecular weight between crosslinks (M_C) 1,000,000–494 g/mol. PVA:CA 7:3 coating allowed the controlled release of 97% allantoin over 8 h, whereas PVA:PAA 7:3 coating exhibited a more prolonged release profile, with 96% of allantoin released over 20 h. Kinetic analyses of the release profiles revealed a good agreement with zero-order release. Full article

Alginate hydrogels offer distinct advantages as ionically crosslinked, biocompatible networks that can be shaped into spherical beads with high compositional flexibility. These spherical architectures provide isotropic geometry, modularity and the capacity for encapsulation, making them ideal platforms for scalable, stimuli-responsive actuation. Their ability to respond to thermal, magnetic, electrical, optical and chemical stimuli has enabled applications in targeted delivery, artificial muscles, microrobotics and environmental interfaces. This review examines recent advances in alginate sphere-based actuators, focusing on fabrication methods such as droplet microfluidics, coaxial flow and functional surface patterning, and strategies for introducing multi-stimuli responsiveness using smart polymers, nanoparticles and biologically active components. Actuation behaviours are understood and correlated with physical mechanisms including swelling kinetics, photothermal effects and the field-induced torque, supported by analytical and multiphysics models. Their demonstrated functionalities include shape transformation, locomotion and mechano-optical feedback. The review concludes with an outlook on the existing limitations, such as the material stability, cyclic durability and integration complexity, and proposes future directions toward the development of autonomous, multifunctional soft systems. Full article

This study reports the development of peptide-based hydrogels for the encapsulation and controlled release of peptide nucleic acids in drug delivery applications. Ultrashort aromatic peptides, such as Fmoc-FF, self-assemble into biocompatible hydrogels with nanostructured architectures. The functionalization of tripeptides (Fmoc-FFK and Fmoc-FFC) with lysine (K) or cysteine (C) enables electrostatic or covalent interactions with model PNAs engineered with glutamic acid or cysteine residues, respectively. Hydrogels were polymerized in situ in the presence of PNAs, and component ratios were systematically varied to optimize mechanical properties, loading efficiency, and release kinetics. The formulations obtained with a 1/10 ratio of Fmoc-FF(K or C)/Fmoc-FF provided an optimal balance between structural integrity and delivery performance. All hydrogel formulations demonstrated high stiffness (G′ > 19,000 Pa), excellent water retention, and minimal swelling under physiological conditions (ΔW < 4%). The release studies over 10 days showed that electrostatic loading enabled faster and higher release (up to 90%), while covalent bonding resulted in slower, sustained delivery (~15%). These findings highlight the tunability of the hydrogel system for diverse therapeutic applications. Full article

Hydrogels have become indispensable in biomedical research and regenerative therapies due to their high water content, tissue-like mechanics, and tunable biochemical properties. However, their behavior under altered gravitational conditions—particularly simulated microgravity (SMG)—presents a frontier of challenges and opportunities that remain underexplored. This comprehensive review provides a detailed comparative analysis of hydrogel performance in normal gravity versus SMG environments, focusing on the structural, physicochemical, and thermodynamic parameters that govern their functionality. We critically examine how microgravity influences polymer network formation, fluid dynamics, swelling behavior, mechanical stability, and degradation kinetics. SMG disrupts convection, sedimentation, and phase separation, often leading to inhomogeneous crosslinking and altered diffusion profiles. These changes can compromise hydrogel uniformity, anisotropy, and responsiveness, which are essential for biomedical applications such as drug delivery, tissue regeneration, and biosensing. To address these limitations, we propose a thermodynamic framework that integrates osmotic pressure regulation, entropy-driven swelling, and pressure–temperature control to enhance hydrogel stability and functionality in low-gravity environments. The integration of predictive modeling approaches—including finite element simulations, phase-field models, and swelling kinetics—provides a robust pathway to design space-adapted hydrogel systems. The review also outlines future directions for optimizing hydrogel platforms in extraterrestrial settings, advocating for synergistic advances in material science, biophysics, and space health. These insights offer a strategic foundation for the rational development of next-generation hydrogel technologies tailored for long-duration space missions and planetary biomedical infrastructure. Full article

Mild to moderate pain for a few hours to several days post-piercing is normal, and the pain is usually accompanied by swelling, redness, and warmth due to the inflammatory response. Cool compresses and over-the-counter analgesics (e.g., NSAIDs) can ease mild discomfort. However, oral NSAIDs may have systemic side effects; for this reason, we propose a topical anti-inflammatory approach. Four pranoprofen-loaded gels were created using different gelling agents: Sepigel^® 305 (PF-Gel-Sep), Carbopol^® 940 (PF-Gel-Car), Pluronic^® F-68 (PF-Gel-Plu), and Lutrol^® F-127 (PF-Gel-Lut). The gels were assessed for pH, morphology, FT-IR spectroscopy, rheological properties, spreadability, swelling and degradation, drug release kinetics, skin permeation (cow and human skin), irritation potential (HET-CAM assay), and impact on skin barrier function (TEWL and SCH). The gels exhibited varied rheological properties with PF-Gel-Car showing high viscosity and PF-Gel-Plu very low viscosity. All gels had similar spreadability with PF-Gel-Lut showing the highest. PF-Gel-Car showed the highest amounts of PF released, whereas PF-Gel-Plu led to the highest amount of pranoprofen retained in human and bovine skin. The HET-CAM assay indicated that none of the PF-Gels were irritating. Additionally, PF-Gel-Car and PF-Gel-Plu showed no cytotoxic effects on HaCaT cells. In vivo testing on mice showed that PF-Gel-Car prevented inflammation, while the rest of the gels were able to revert it in 25 min. Skin tolerance tests revealed the gels did not affect TEWL, and some gels improved SCH. The study successfully formulated and characterized four PF-loaded topical gels with potential to be used as an alternative for treating inflammation from piercings and ear tags. Full article

Oral solid drug delivery continues to be the gold standard in pharmaceutical formulations, owing to its cost-effectiveness, ease of administration, and high patient compliance. Tablets, the most widely used dosage form, are favored for their precise dosing, simplicity, and economic advantages. Among these, controlled release (CR) tablets stand out for their ability to maintain consistent drug levels, enhance therapeutic efficacy, and reduce dosing frequency, thereby improving patient adherence and treatment outcomes. A well-designed CR system ensures a sustained and targeted drug supply, optimizing therapeutic performance while minimizing side effects. This review delves into the latest advancements in CR formulations, with a particular focus on hydrophilic matrix systems, which regulate drug release through mechanisms such as swelling, diffusion, and erosion. These systems rely on a variety of polymers as drug-retarding agents to achieve tailored release profiles. Recent breakthroughs in crystal engineering and polymer science have further enhanced drug solubility and bioavailability, addressing critical challenges associated with poorly soluble drugs. In terms of manufacturing, direct compression has emerged as the most efficient method for producing CR tablets, streamlining production while ensuring consistent drug release. The integration of the Quality by Design framework has been instrumental in optimizing product performance by systematically linking formulation and process variables to patient-centric quality attributes. The advent of cutting-edge technologies such as artificial intelligence and 3D printing is revolutionizing the field of CR formulations. AI enables predictive modeling and data-driven optimization of drug release profiles, while 3D printing facilitates the development of personalized medicines with highly customizable release kinetics. These innovations are paving the way for more precise and patient-specific therapies. However, challenges such as regulatory hurdles, patent constraints, and the need for robust in vivo validation remain significant barriers to the widespread adoption of these advanced technologies. This succinct review underscores the synergistic integration of traditional and emerging strategies in the development of CR matrix tablets. It highlights the potential of hydrophilic and co-crystal matrix systems, particularly those produced via direct compression, to enhance drug bioavailability, improve patient adherence, and deliver superior therapeutic outcomes. By bridging the gap between established practices and innovative approaches, this field is poised to address unmet clinical needs and advance the future of oral drug delivery. Full article

N-isopropylacrylamide and methacrylic acid were copolymerized by a free radical polymerized mechanism. The obtained hydrogel poly(N-isopropylacrylamide-co-methacrylic acid) hydrogels, poly(NIPAM-co-MAA), were utilized as sorbent material for removal Cr(VI), Mn(II), and Pb(II) ions from simulated aqueous solutions. Hydrogel structures before and after heavy metal sorption are characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The swelling results indicate that poly(NIPAM-co-MAA) hydrogels are pH- and temperature-sensitive and have high swelling reversibility through three swelling/contraction cycles. The studied parameters of heavy metal sorption include the effect of pH, the initial concentration of heavy metal, the effect of temperature, and the desorption of metal ions. The maximum sorption capacities of poly(NIPAM-co-MAA) hydrogels were determined at pH 4.5 and 25 °C, and they are, for Cr(VI), Mn(II), and Pb(II) ions, 289.35 mg/g, 190.59 mg/g, and 349.71 mg/g, respectively. The pseudo-second-order model and the Langmuir adsorption isotherm best describe the sorption of heavy metal ions onto hydrogels. The removal of heavy metals is an exothermic reaction, and the interaction mechanism between the metal and the hydrogel is primarily physical in nature. Results of three sorption/desorption cycles show a good desorption ratio and sorption capacity of poly(NIPAM-co-MAA) hydrogels. Full article

In this study, a full multilevel factorial design (2¹ × 3¹ × 2¹) × 2 was conducted to investigate the effects of molar mass of chitosan (CS), the type of acid used for dissolution, and the composition of the coagulation bath on the coagulation, mechanical properties, and swelling of the filaments. The results showed the statistical significance of the factors in the characteristics of these filaments. The coagulation followed Fick’s second law of diffusion, with an increase in the chitosan molar mass reducing the coagulation rate, as did the use of acetic acid instead of lactic acid. CS with higher molar mass produced filaments with larger diameters, but without a proportional increase in tensile strength. Swelling was influenced by the acid and composition of the coagulation bath. The interaction of CS with acid and the CS molar mass factor were the terms of greatest statistical significance. Crystallinity was higher for samples dissolved in aqueous solutions of acetic acid and coagulated with ethanol, while lactic acid induced greater structural disorder. Samples coagulated with ethanol presented more homogeneous surfaces, while methanol resulted in rougher filaments. These findings emphasize the critical role of processing conditions in tailoring the properties of CS filaments, providing valuable insights for their optimization for biomedical applications. Full article

Superabsorbent hydrogels used in products like diapers, hygiene items, and medical patches depend on their swelling ratio. However, improving the swelling performance across hydrogel assemblies remains challenging. This study identifies a decline in the water absorption capacity in hydrogel assemblies with high swelling ratios, as confirmed through MRI analysis, and introduces a solution using a branched crosslinker to address this issue. The branched crosslinker was synthesized by grafting acrylate groups onto poly(aspartic acid)s. This branched poly(aspartic acid) crosslinker was incorporated into hydrogels with the same number of acrylate groups as PEGDA575, a conventional linear crosslinker, and their absorption performance and behavior were compared. The results showed that hydrogels with the branched crosslinker exhibited a swelling ratio twice as high as the PEGDA575 group, with a slower initial absorption rate, demonstrating a more gradual swelling behavior. Additionally, while the initial absorption rate was approximately 30% slower than the PEGDA575 group, the absorption rate showed a gradual decrease of less than 15% within the first 30 min, indicating sustained absorption behavior. Overall, the new strategy presented in this study of introducing a branched crosslinker into hydrogels is expected to be a useful application for existing industries by enhancing swelling ratios and promoting continuous absorption. Full article