Search Results (299)

(1) Background: Cerium silicate (CeSi) nanoparticles (NPs) have potential as a restorative filler particle with multifunctional properties to improve longevity. To increase the biological activity, these nanoparticles can be fabricated with ultrasmall pores (mesoporous) (MPCeSi-NP) that can be loaded with a polyphosphate inhibitor, such as gallein. (2) Methods: MPCeSi-NPs were custom-synthesized with a microemulsion method, using cetyltrimethylammonium bromide (CTAB) as a template for self-assembly. Biocompatibility with oral keratinocytes/fibroblasts was tested, with the addition of examining the biomineralization potential with human bone-marrow-derived mesenchymal stromal cells (BM-MSCs). MPCeSi-NP, loaded with gallein, was tested against Rothia dentocariosa (Rd). MPCeSi-NP was added to a resin matrix of triethylene glycol dimethacrylate (TEGDMA) and Bisphenol A-glycidyl methacrylate (BisGMA) with subsequent mechanical properties evaluation. (3) Results: MPCeSi-NPs had high biocompatibility with oral keratinocytes and fibroblasts, especially at concentrations below 300 µg/mL. MPCeSi-NPs induced the biomineralization of BM-MSCs. Higher cerium levels increased mineralization. MPCeSi-NP had weak antimicrobial activity against Rd. At 1% wt, MPCeSi-NPs did not reduce the polymerization potential and mechanical properties of a TEGDMA:BisGMA polymer material, with controlled release of gallein in a simulated degradation model. (4) Conclusions: MPCeSi-NPs are highly biocompatible and bioinductive and have the potential to improve the biological response of current restorative materials. Full article

Porous glycidyl methacrylate-based copolymers crosslinked with ethylene glycol dimethacrylate (EGDMA) and trimethylolpropane trimethacrylate (TMPTMA) were synthesized via suspension–emulsion polymerization and subsequently functionalized with triethylenetetramine. The effect of the monomer composition on the epoxy group content and porous structure was systematically investigated by varying the GMA-to-crosslinker molar ratio from 1:1 to 5:1. Increasing the GMA fraction enhanced the epoxy group content (2.8–5.0 mmol/g) but significantly reduced the specific surface area (333–23 m²/g), indicating a trade-off between functionality and porosity. ATR-FTIR and elemental analysis confirmed successful amine functionalization while preserving a considerable degree of porosity. The modified copolymers were evaluated for Cr(VI) removal, showing strong pH dependence, with maximum efficiency at pH 3 due to electrostatic interactions between protonated amine groups and HCrO₄⁻ ions. Equilibrium studies revealed saturation-type behavior, with a maximum sorption capacity of 165.47 mg/g for TMPTMA-based copolymers. Despite the higher nitrogen content in EGDMA-based materials, TMPTMA-crosslinked copolymers exhibited a superior adsorption performance, demonstrating that pore accessibility, rather than functional group density alone, governs adsorption efficiency. These findings provide insight into the rational design of amine-functionalized porous polymer sorbents for efficient chromium(VI) removal. Full article

Background/Objectives: Diabetic wound healing faces significant challenges due to the harsh microenvironment of wounds such as high blood glucose levels, excessive inflammation, persistent infection, upregulated reactive oxygen species (ROS), and damaged new blood vessels. Therefore, developing hydrogel dressings with microenvironmental regulation functions has become an important strategy in treating diabetic wounds. Methods: In this study, an ultraviolet in situ crosslinked hydrogel (D@H/E) was developed using methacrylic anhydride modified hyaluronic acid (HA-MA) and glycidyl methacrylate modified ε-polylysine (EPL-GMA), loaded with the iron chelating agent desferrioxamine (DFO). The physicochemical and biochemical properties of the hydrogel were comprehensively characterized, and its efficacy as a dressing for diabetic wounds was evaluated in a STZ-induced hyperglycemic mouse model. Results: This hydrogel demonstrated remarkable multidimensional effects by alleviating oxidative stress damage, inhibiting bacterial infection, regulating inflammatory responses, mitigating ferroptosis, and promoting cell migration and tubule formation. Specifically, the DFO-loaded hydrogel achieved a high DPPH radical scavenging efficiency of 80.8% and exhibited excellent antibacterial activity, with over 99.8% inhibition against both S. aureus and E. coli. In streptozotocin (STZ)-induced diabetic mice, the hydrogel accelerated wound closure to near completion by day 14. Mechanistically, it significantly upregulated CD206 expression to promote M2 macrophage polarization, upregulated the expression of angiogenesis-related factors to promote angiogenesis at the wound site, and enhanced GPX4 expression to alleviate ferroptosis. Conclusions: By orchestrating multi-dimensional synergy that combines ROS scavenging, infection control, immune regulation, and anti-ferroptosis, this D@H/E hydrogel system effectively remodels the harsh diabetic wound microenvironment, offering a promising platform for chronic wound management. Full article

Poly(glycidyl methacrylate) (PGMA) is a polymer containing epoxy groups in its side chains, which makes it a suitable platform for the development of functional materials. In this study, crosslinked PGMA-based microspheres were synthesized by suspension polymerization using N,N′-methylenebisacrylamide as a crosslinker, and the effect of incorporating inorganic additives (InAds) (NaCl, CaCO₃, and MgO nanoparticles) during synthesis was evaluated. In all cases, solid microspheres were obtained, exhibiting variations in particle size, sphericity, and aggregation depending on the type and amount of InAds. Thermal stability was characteristic of crosslinked PGMA (i.e., a single broad thermal transition in ~80–110 °C), while water absorption remained within a narrow range (80–120% for t = 40 min). In addition, the number of epoxy groups per gram of sample was 4.83 ± 0.02 mmol g⁻¹. Selected microspheres were subsequently functionalized with polyethyleneimine (PEI) to obtain graft polymers (PGMA–PEI) and evaluated for the adsorption of three model contaminants: Acid Red 27 (AR-27), nitrites, and acetaminophen. PGMA–PEI showed high affinity toward AR-27 and nitrites, achieving high removal efficiencies at acidic and neutral pH, with rapid adsorption kinetics consistent with a pseudo-second-order model, attributed to electrostatic interactions between protonated amine groups and anions. At pH 11, anion desorption was promoted, enabling partial material regeneration. The results highlight the potential of PGMA–PEI microspheres for the removal of AR-27 (maximum retention ~0.25 mg of dye/g of polymer) and nitrites (maximum retention ~0.023 mg of ${NO}_2^{-}$/g of polymer), whereas acetaminophen removal was not evidenced. Full article

Hydrogels are widely investigated as drug carriers for cancer therapy due to their ability to provide sustained release and reduce systemic side effects. In this study, MeBSA–PNIPAm hydrogels were developed as dual-temperature and pH-responsive systems for gastrointestinal delivery of 5-FU. MeBSA was successfully synthesized using glycidyl methacrylate and confirmed by FTIR and ¹H-NMR analyses. Hydrogels with varying MeBSA/NIPA ratios were prepared via redox polymerization. DSC results showed that increasing MeBSA content shifted the phase transition temperature of hydrogels, while TGA analysis revealed enhanced thermal stability with higher MeBSA incorporation. Temperature-dependent swelling experiments further demonstrated that the VPTT slightly shifted depending on the surrounding pH, indicating that the thermoresponsive behavior of the hybrid network is influenced by the pH-dependent charge state of the protein component. Swelling studies performed at 30, 37, and 40 °C and at pH 1.2 and 7.4 confirmed dual-responsive behavior. Drug loading efficiencies above 70% were achieved for all formulations. In vitro release studies at 37 °C demonstrated distinct composition-dependent release profiles. During the first 2 h, all hydrogels exhibited controlled and limited release without burst behavior under acidic conditions. Following the transition to pH 7.4, a composition-dependent increase in drug release was observed. GEL 4 achieved the fastest and highest cumulative release (91%), whereas GEL 1 provided the most sustained release over 72 h (32%). Kinetic analysis indicated diffusion-controlled release, best described by the Weibull and Korsmeyer–Peppas models. Cytocompatibility tests showed that fibroblast viability improved with increasing MeBSA content. Overall, protein-modulated dual-responsive hydrogels offer tunable and biocompatible platforms for stimuli-responsive gastrointestinal drug delivery applications. Full article

This study investigates the key performance-related fuel properties of emulsifier–diesel solutions and ethanol-in-diesel microemulsions. This work begins with the in situ polymerization of long alkyl chain-substituted glycidyl methacrylate (R-GMA) in diesel and the optional presence of a second methacrylate monomer. The resulting diesel-soluble oligomer functions as a nonionic emulsifier. Controlled amounts of ethanol are subsequently incorporated into the emulsifier–diesel solution to form a stable microemulsion, referred to as E-Diesel. This study examines how the structure of the emulsifier influences key fuel properties, including (i) ethanol–diesel miscibility, (ii) gross calorific value, (iii) Ramsbottom carbon residue (% of fuel), (iv) entrapped polycyclic aromatic hydrocarbons (PAHs), and (v) fuel lubricity. Both the hydrophilic–hydrophobic balance and the structure of the emulsifier side chains are found to significantly affect these properties. Compared with neat diesel, oligomeric emulsifiers enable the substantial dispersion of ethanol in diesel (up to 18 wt.%). The resulting fuel exhibits a gross calorific value exceeding the theoretical sum of diesel and ethanol at the same composition (a synergistic effect) and achieves an enhancement in lubricity up to 49.5% relative to neat diesel at a 5% emulsifier loading. Although the presence of emulsifiers leads to an increase in the carbon residue by up to 54.7% compared to neat diesel during controlled pyrolysis, it simultaneously reduces the PAH content in the exhaust. Overall, this study establishes fundamental correlations among microemulsion stability, combustion synergy, carbon residue formulation, and fuel lubricity, which are governed by the structure of the emulsifier. Full article

Polyethylene terephthalate (PET) has become the predominant material for single-use packaging owing to its cost and performance advantages. However, massive post-consumer waste leads to environmental concerns, and recycled PET from thermomechanical processing followed by chain extension often suffers from low toughness and poor processability, restricting its use to low-value applications. In this study, halloysite nanotubes (HNTs) and ethylene–methyl acrylate–glycidyl methacrylate random terpolymer (E-MA-GMA) were melt-blended with recycled PET to examine their synergistic modification effects. The DSC results show that HNTs retain a nucleating effect on recycled PET even with the co-addition of E-MA-GMA, albeit with a substantial reduction compared with their effect when used alone. Nevertheless, rheological measurements indicate that the combined introduction of E-MA-GMA and HNTs imposes a significantly stronger restriction on the relaxation behavior of recycled PET molecular chains than the individual addition of either HNTs or E-MA-GMA. This is attributed to the interfacial reactions between E-MA-GMA and the recycled PET matrix, as well as between E-MA-GMA and HNTs, leading to the formation of branching and hybrid structures. This synergistic restraint markedly reduces the crystallization growth rate of PET. As a result, the recycled PET/E-MA-GMA/HNTs composites maintain relatively lower crystallinity compared with the recycled PET/E-MA-GMA composite after high-temperature injection molding or annealing treatment, leading to superior impact resistance. The impact strength of the recycled PET/E-MA-GMA/HNTs composites is 2.28 and 2.14 times that of the recycled PET/E-MA-GMA composite under high-mold-temperature injection molding and annealing conditions, respectively. The approach presented here facilitates the substitution of virgin plastics with recycled PET in demanding applications. Full article

In this study, magnetic porous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer (mP) grafted with tetraethylenepentamine (mP-TEPA) obtained in a two-step procedure was tested as the CO₂ sorbent. The morphological, textural, structural, and thermal characterization of the sample was determined by scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), mercury intrusion porosimetry (MIP), nitrogen physisorption at 77 K, Fourier transform infrared spectroscopy in ATR mode (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), elemental analysis, and thermogravimetric analysis (TGA). The effects of thermodynamic and kinetic parameters, as well as the adsorption/desorption mechanism on the CO₂ sorption ability of mP-TEPA, were investigated using a pulse gas chromatographic method. Under optimal adsorption conditions, the CO₂ sorption capacity reached 6.20 mmol CO₂/g (6.20 × 10⁻² mmol CO₂/m²). Temperature-programmed desorption (TPD) experiments were conducted to calculate the activation energy of CO₂ desorption. The low desorption activation energy of 18.80 kJ/mol and high desorption rate, with stable CO₂ uptake after ten adsorption/desorption cycles, suggest that mP-TEPA is a potentially excellent sorbent for CO₂ adsorption. Full article

Corneal nerves are essential for maintaining the functional integrity of the ocular surface. Damage to corneal nerves can lead to corneal issues and impaired vision. Current treatments for corneal nerve damage are inadequate, thus highlighting the need for innovative therapeutic approaches. In this study, we present a hydrogel microneedle system designed to facilitate the sustained release of recombinant human nerve growth factor (rhNGF). The microneedle features a tip composed of glycidyl methacrylate modified silk fibroin (SFMA) loaded with rhNGF, photopolymerized for structural integrity, while its base is formed using silk fibroin (SF). This design allows the microneedles to penetrate the corneal epithelium and deliver rhNGF to the sub-epithelial layer. The crosslinking process not only provides the mechanical strength required for microneedle penetration but also enables sustained drug release. The proposed rhNGF-loaded SF hydrogel microneedle provides a platform for drug delivery, serving as a novel therapeutic option for corneal tissue engineering. Full article

Conventional polycarboxylate superplasticizers (PCEs) suffer from uncontrollable adsorption, characterized by rapid initial uptake and limited subsequent release, which causes pronounced slump loss, particularly at elevated temperatures where hydration accelerates and dispersion efficiency declines. To overcome these limitations, we developed a series of chitosan-based upper critical solution temperature (UCST) responsive superplasticizers (Thermo-PCE_x, UCST = 40–42 °C) capable of temperature -adaptive dispersion during cement hydration. A vinyl-functionalized chitosan macromonomer (uCS-g-T₈) was synthesized by reacting cetyl polyoxyethylene glycidyl ether with chitosan, followed by methacrylate modification, and then copolymerized with acrylic acid and isopentenol polyoxyethylene ether to yield Thermo-PCE_x with tunable sugar-to-acid ratios. The polymers exhibited clear UCST-type phase-transition behavior in aqueous solution. When incorporated into cement paste, Thermo-PCE_x enabled continuous fluidity enhancement at 25 °C (<UCST), with increases of 43.6%, 52.9%, 62.3% and 63.6%, after 180 min for x = 0.5, 1, 1.5 and 2, respectively. Adjusting dosage and composition further regulated setting time, improved rheological stability, and enhanced mechanical strength. These findings demonstrate a viable pathway for designing bio-based, temperature-responsive superplasticizers with self-adaptive dispersibility for sustainable cement technologies. Full article

The removal of water pollutants with high selectivity and efficiency is still a huge challenge owing to the complex composition of contaminated water. The preparation, modification of Pickering emulsion microspheres, and their application in the adsorption and removal of non-steroidal anti-inflammatory drugs (diclofenac) in water were studied. Poly(2-(diethylamino)ethyl methacrylate-divinylbenzene), (P(DEAEMA-DVB)) microspheres were prepared by Pickering emulsion polymerization. The P(DEAEMA-DVB) polymer was modified with glycidyl trimethylammonium chloride (GTAC) and phenyl glycidyl ether (PGE) to prepare the adsorbent poly(quaternized and phenyl-functionalized) (P(QP-DVB)) with a substantial quantity of quaternary ammonium functional groups. The non-steroidal anti-inflammatory drugs in aqueous solution was mainly adsorbed by the anion exchange interaction with quaternary ammonium species. The adsorption kinetics coincided with the pseudo-second-order kinetic model, and the adsorption isotherm conformed to the Langmuir isotherm model. The optimized P(QP-DVB) particles exhibited well-defined spherical morphology and a uniform particle size distribution ranging from 15 to 30 µm. Nitrogen adsorption/desorption characterization revealed a high specific surface area of 674 m² g⁻¹ and a pore size distribution from 2 to 25 nm. In addition, the aforementioned microsphere underwent chemical regeneration and exhibits good reusability, thereby reducing both the economic costs and environmental impacts. Full article

Nanogels provide unique opportunities for stabilizing fragile enzymes through soft, hydrated polymer networks. Here, we report the development of a glutathione peroxidase (GPx)-loaded nanogel (GPxNG) engineered via a mild “grafting-to” epoxy–amine coupling strategy to enhance enzyme stability and antioxidant function. An amphiphilic copolymer composed of methacrylated 2,2,6,6-tetramethyl-4-piperidyl (PMA) and glycidyl methacrylate (GMA) was synthesized by controlled reversible addition–fragmentation chain-transfer (RAFT) polymerization using a poly(ethylene glycol) (PEG) macro-chain transfer agent (macro-CTA), yielding well-defined polymer chains with reactive epoxy groups. Covalent conjugation between polymer epoxides and GPx enzyme surface amines generated soft, PEGylated nanogels with high coupling efficiency, uniform particle sizes, and excellent colloidal stability. The engineered nanogels exhibited shear-thinning injectability, robust storage stability, and non-cytotoxic behavior in RAW 264.7 macrophages. Compared with native GPx enzyme, GPxNGs demonstrated significantly enhanced reactive oxygen species (ROS) scavenging activity, including strong inhibition of lipid peroxidation and copper-induced low-density lipoprotein (LDL) oxidation. Importantly, the nanogels preserved GPx enzyme activity after extended storage, freeze–thaw cycles, and repeated catalytic use, whereas the free enzyme rapidly lost function. This protective effect arises from the nanoscale confinement of the GPx enzyme within the flexible PEG-based network, which limits unfolding and aggregation. Overall, this work introduces a simple and biocompatible “grafting-to” nanogel platform capable of stabilizing redox-active enzymes without harsh conditions. The GPx nanogels combine high enzymatic preservation, potent antioxidant activity, and excellent handling properties, highlighting their potential as a therapeutic nanoplatform for mitigating oxidative stress-associated disorders such as atherosclerosis. Full article

Although micro-arc oxidation (MAO) coatings are widely used due to their corrosion and wear resistance, their inherent micro-pore defects seriously affect their service life. The conventional sealing materials to these defects often fail to bond well with the pore wall due to volume shrinkage during curing, resulting in a service life that still does not meet expectations. Here, a novel pore-sealant is prepared to overcome the issue by adding nano calcium sulfoaluminate (CAS) expansive fillers. The modified CAS particles were compounded with glycidyl methacrylate (CAS sealant) and were driven to seal the micro-pores of MAO coatings by negative pressure. Results indicate that the surface porosity of the MAO coating decreased almost to zero after sealing treatment with the CAS sealant. Its low-frequency impedance |Z|_0.01Hz remained at 10⁸ Ω·cm² after 672 h of immersion, which is three orders of magnitude higher than that achieved by traditional sealing methods. The mechanism is that the interface defects at fillers/pore walls are filled by the sealant volume expansion due to CAS water absorption, which significantly inhibits the rate of corrosion medium penetration into the coating. Full article

This study presents water-repellent coatings for pine wood surfaces based on epoxy varnish modified with glycidyl methacrylate–(fluoro)alkyl methacrylate copolymers, achieving superhydrophobic properties with contact angles up to 155° while maintaining the natural texture of the wood. The influence of the application method on the microtexture and water-repellent properties of the coatings has been demonstrated. Incorporating functional copolymers considerably improves water resistance: after 60 days of immersion, water absorption is reduced more than threefold compared to coatings made with unmodified epoxy varnish. Furthermore, the coatings maintain their water-repellent properties and preserve the wood’s appearance even after six months of exposure to the tropical climate of South Vietnam. Full article

This study aimed to assess how different resin matrix formulations affect the fatigue resistance of resin dental composites. Model dental composites were formulated using six distinct monomer mixtures: two Bis-GMA (bisphenol A-glycidyl methacrylate):TEGDMA (triethylene glycol dimethacrylate) (60:40 and 80:20 mole%), two UDMA (urethane dimethacrylate):TEGDMA (60:40 and 80:20 mole%), one Bis-GMA:UDMA:TEGDMA (35:35:30 mole%), and one Fit852:UDMA:TEGDMA (35:35:30 mole%). Cyclic fatigue resistance (CFR) of the resin composites was measured in a biaxial test mode using staircase analysis. Additional evaluations included biaxial flexural strength (BFS), degree of conversion (DC), water sorption (WS), and viscoelastic properties of the unfilled resins, such as the storage modulus (E′), loss modulus (E″), tan δ (E″/E′), and stiffness (k′). Data were subjected to one-way ANOVA with Tukey post hoc analyses. Pearson correlation and stepwise regression analyses were conducted to examine the relationships among variables. The UT6040 model composite exhibited the highest CFR (82.61 ± 8.83 MPa), significantly outperforming other formulations. Tan δ of the resin matrix showed the strongest correlation with CFR (r = 0.974), and was also shown to be the most influential predictor for the CFR of the particulate composites. The composition of the resin matrix has a significant impact on the CFR of dental composites. Among the properties evaluated, the viscoelastic parameter tan δ emerged as a strong and reliable predictor of CFR, emphasizing the importance of targeting viscoelastic behavior in the design of dental composite formulations. Full article