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•High-performance coating with promising active inhibition/barrier corrosion retardation features was fabricated.•The zirconium-based MOFs were constructed using terephthalic acid and ...2-aminoterephthalic acid.•The excellent barrier properties of the GMA@NH2-UIO filled epoxy coating were proved.•The smart pH-sensitive controlled-release activity of the GMA@NH2-UIO was proved.
For the first time, the UIO-66, NH2-UIO, and NH2-UIO particles covalently functionalized by Glycidyl Methacrylate (GMA@NH2-UIO), were utilized as the novel functional anti-corrosive fillers. The functionality, high surface area, phase composition, excellent thermal properties as well as chemical stability of the Zr-MOFs were proved by FT-IR, BET, XRD, TGA, and water stability tests, respectively. The smart pH-sensitive controlled-release activity of the corrosion inhibitors (i.e., Zr ions and organic compounds) from the prepared Zr-MOFs was proved by the water stability test of the Zr-MOFs particles in the acidic (pH = 2), neutral (pH = 7.5), and alkaline (pH = 12) solutions containing 3.5 wt% sodium chloride. The active inhibition properties of the Zr-MOFs were obtained in saline solution by two methods of (i) the solution phase and (ii) scratched epoxy coated samples containing Zr-MOFs by Tafel polarization method and EIS analysis. According to the EIS data, the excellent barrier (passive) properties of the composite film filled with GMA@NH2-UIO particles (G-UIN/EP) were proved by the highest impedance level at the lowest f (frequency) (log (|Z|10 mHz = 9.86 Ω.cm2), the lowest value of the breakpoint frequency (log (fb) = −1.42 Hz) and the highest coating undamaged index (85.93%) after 120 h of immersion. The salt spray (accelerated corrosion test) test (SST), pull-off (testing the strength of adhesion), and cathodic disbonding test (CDT) experiments showed excellent interfacial-adhesion properties of the G-UIN/EP sample in two dry (unexposed) and wet conditions. The hardness test showed that through the incorporation of the UIO, UIN, and G-UIN particles into the epoxy coating, the hardness, and scratch-resistance of the coating were notably improved.
Bisphenol A‐glycidyl methacrylate (BisGMA) is a methacrylate monomer that is mainly used in three‐dimensional structures to reconstruct dental and bony defects. BisGMA has toxic and proinflammatory ...effects on macrophages. Rutin is a natural flavonol glycoside that is present in various plants and has useful biological effects, such as anti‐inflammatory, anticancer, and antioxidative effects. The aim of this study was to investigate the anti‐inflammation of rutin in macrophages after exposure to BisGMA. Pretreatment of the RAW264.7 macrophage with rutin at 0, 10, 30, and 100 μM for 30 min before being incubated with BisGMA at 0 or 3 μM. Proinflammatory cytokines and prostaglandin (PG) E2 were detected by enzyme‐linked immunosorbent assay (ELISA). Nitric oxide (NO) was detected by the Griess assay. Expression and phosphorylation of proteins were measured by Western blot assay. Pretreatment with rutin inhibited the BisGMA‐induced generation of proinflammatory cytokines, including tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, IL‐6, and PGE2, in macrophages. Rutin also suppressed the BisGMA‐induced secretion of NO and expression of inducible nitric oxide synthase (iNOS) in a concentration‐dependent manner. Furthermore, rutin suppressed the mitogen‐activated protein kinase (MAPK) phosphorylation in a concentration‐dependent manner. Finally, rutin suppressed the BisGMA‐induced phosphorylation of nuclear factor (NF)‐κB p65 and degradation of inhibitor of κB (IκB). These results indicate that the concentration of rutin has an inhibitory effect on proinflammatory mediator generation, MAPK phosphorylation, NF‐κB p65 phosphorylation, and IκB degradation. In conclusion, rutin is a potential anti‐inflammatory agent for BisGMA‐stimulated macrophages through NF‐κB p65 phosphorylation and IκB degradation resulting from MAPK phosphorylation.
The main aim of this study was to perform an integrative review on the release of bisphenol A (BPA) from resin‐matrix composites and potential toxic effects. A bibliographic search was performed on ...the PubMed platform using the following keywords: “Bisphenol A" OR “BPA” AND “resin composite” OR “composite resin” AND “toxicity” OR “cytotoxicity” OR “release”. Inclusion criteria involved in vitro and in vivo studies on the release and toxicity of BPA. Results highlighted the release of BPA from resin‐matrix composites due to insufficient polymerization and/or degradation of the polymeric matrix. BPA is part of the organic matrix of resin‐matrix composites and may be hydrolysed in human saliva, although studies report that low doses might not be detected by traditional chemical analysis. Studies exposing zebrafish embryos to different concentrations of Bis‐GMA, showed 55% mortality at 10 μM Bis‐GMA while 30% mortality was recorded at 1 μM Bis‐GMA. In patients, a BPA concentration of around 2.09 × 10−2 μg/ml was found in the saliva after placement of lingual orthodontic retainers with resin‐matrix composites. Also, the BPA molecule can be swallowed and absorbed by the oral/gastrointestinal mucosa, which might result in systemic toxicity. The degradation of resin‐matrix composites and release of BPA in oral environment are dependent on the organic matrix content and on the polymerization method. A increased release of BPA can lead to the absorption into oral and gastrointestinal mucosa with high risks of local and systemic toxicity.
Bisphenol A (BPA) can be released from resin composites due to the degradation or insufficient polymerization of the restorative material. BPA released from resin composites can penetrate into the oral mucosa (i.e., gingival margin) resulting in localized toxicity. Also, BPA abosorbed by oral and gastrointestinal mucosa can be diffused into the bloodstream resulting in systemic toxicity.
Three-dimensional printing with Digital Lighting Processing (DLP) printer has come into the new wave in the tissue engineering for regenerative medicine. Especially for the clinical application, it ...needs to develop of bio-ink with biocompatibility, biodegradability and printability. Therefore, we demonstrated that Silk fibroin as a natural polymer fabricated with glycidyl-methacrylate (Silk-GMA) for DLP 3D printing. The ability of chondrogenesis with chondrocyte-laden Silk-GMA evaluated in vitro culture system and applied in vivo. DLP 3D printing system provided 3D product with even cell distribution due to rapid printing speed and photopolymerization of DLP 3D printer. Up to 4 weeks in vitro cultivation of Silk-GMA hydrogel allows to ensure of viability, proliferation and differentiation to chondrogenesis of encapsulated cells. Moreover, in vivo experiments against partially defected trachea rabbit model demonstrated that new cartilage like tissue and epithelium found surrounding transplanted Silk-GMA hydrogel. This study promises the fabricated Silk GMA hydrogel using DLP 3D printer could be applied to the fields of tissue engineering needing mechanical properties like cartilage regeneration.
The aim was to evaluate the effect of short glass-fiber/filler particles proportion on fracture toughness (FT) and flexural strength (FS) of an experimental flowable fiber-reinforced composite ...(Exp-SFRC) with two methacrylate resin formulations. In addition, we wanted to investigate how the fracture-behavior of composite restorations affected by FT values of SFRC-substructure.
Exp-SFRC was prepared by mixing 50wt% of dimethacrylate based resin matrix (bisGMA or UDMA based) to 50wt% of various weight fractions of glass-fiber/particulate filler (0:50, 10:40, 20:30, 30:20, 40:10, 50:0wt%, respectively). FT and FS were determined for each experimental material following standards. Specimens (n=8) were dry stored (37°C for 2 days) before they were tested. Four groups of posterior composite crowns (n=6) composed of different Exp-SFRCs as substructure and surface layer of commercial particulate filler composite were fabricated. Crowns were statically loaded until fracture. Failure modes were visually examined. The results were statistically analysed using ANOVA followed by post hoc Tukey’s test.
ANOVA revealed that ratio of glass-fiber/particulate filler had significant effect (p<0.05) on tested mechanical properties of the Exp-SFRC with both monomer systems. Exp-SFRC (50wt%) had significantly higher FT (2.6MPam1/2) and FS (175.5MPa) (p<0.05) compared to non-reinforced material (1.3MPam1/2, 123MPa). Failure mode analysis of crown restorations revealed that FT value of the substructure directly influenced the failure mode.
This study shows that short glass-fibers can significantly reinforce flowable composite resin and the FT value of SFRC-substructure has prior importance, as it influences the crack arresting mechanism.
A metal organic framework (MOF) modified with amino group (NH2-UiO-66) was functionalized with glycidyl methacrylate (GMA) via ring opening reaction between the amine species in the framework and ...epoxy groups in GMA. The products were characterized by X-ray powder diffraction (XRD), nuclear magnetic resonance (NMR) spectroscopy, field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and N2 adsorption–desorption measurements to monitor their textural properties before and after functionalization. The BET surface area, pore volume, and pore diameter of NH2-UiO-66 were reduced after treatment with GMA. However, the crystalline structure, morphology, and thermal stability were retained. Single-gas adsorption isotherm measurements exhibited that CO2 adsorption capacity of GMA-UiO-66 was enhanced comparatively due to the presence of many polar functional groups including primary and secondary amines, ester, alkene, and hydroxyl groups. Moreover, GMA-UiO-66 showed higher adsorption selectivity against CO2 in CO2/N2 mixture than NH2-UiO-66.
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•NH2-UiO-66 was functionalized by GMA via post synthetic modification.•GMA introduced many polar groups and alkene group on the surface of MOF.•GMA-UiO-66 improved remarkably CO2/N2 separation.•Functionalization with GMA enhanced adsorption of carbon dioxide.
•PGMA with different molecular weight was synthesized as reactive compatibilizers.•Super-toughed and biodegradable PLA/PBAT blends were prepared by reactive melt blending.•Interface-localized ...copolymers markedly enhance interfacial adhesion and compatibility between PLA and PBAT.•New ideas for the design of efficient compatibilizers for biodegradable polyesters were provided.
Poly (glycidyl methacrylate) (PGMA) with different molecular weight (Mw) were synthesized and used as reactive compatibilizers to prepare super-toughed and biodegradable polylactide/poly (butylene adipate-co-terephthalate) (PLA/PBAT) blends. The epoxy group of PGMA can in-situ react with the end groups of PLA and PBAT, thus improving the interfacial adhesion between PLA and PBAT by forming PLA-g-PBAT copolymers. The effects of Mw and content of PGMA on phase morphology and physical properties of the PLA/PBAT blends were systematically investigated. The Mw takes an important role in its dispersion between the PLA and the PBAT phases, and consequently influences the mechanical performance. Interestingly, the PBAT domain size in the PLA matrix decreased from 3.7 μm to 1.7 μm after incorporation of even 0.5 wt% PGMA with a Mw of 44 kDa, and the in-situ improved compatibility leading to that the tensile strength and elongation at break of the PLA/PBAT blends increased by 35% and 87%, respectively. On the contrary, the size of the PBAT domains increased to > 5 μm and the mechanical properties of the PLA/PBAT blends decrease obviously with the same content but a higher Mw (90 kDa) of PGMA, because the higher Mw PGMA dispersed and reacted solely with the PLA matrix, and the enhanced melt viscosity of the PLA matrix could result in a non-uniform dispersion of the PBAT. Therefore, this work provides new insight in designing and preparation of efficient compatibilizers for biodegradable polyesters.
to assess the impact of universal adhesives, cured with single-peak and polywave LEDs, on the metabolic activity and cytokine release of human dental pulp stem cells (hDPSCs). In addition, analyze ...the degree of conversion (DC) of the adhesives cured with the different LEDs.
Discs (5 mm diameter, 1 mm thick) were prepared using three universal adhesives: Single Bond Universal (SBU, 3 M ESPE), Optibond Universal (OBU, Kerr), and Zipbond Universal (ZBU, SDI). These discs were cured for 40 s using a single-peak (DeepCure, 3 M ESPE) or a polywave light-emmiting diode (LED) curing unit (Valo Grand, Ultradent). After 24 h, the specimens were placed in 24-well culture plates, each containing 1 mL of culture medium for 24 h. hDPSCs (1.8 ×10
) were seeded in 96-well plates and allowed to grow for 24 h. Subsequently, the cells were exposed to the extracts (culture medium containing eluates from the adhesive discs) for an additional 24 h. Cells not exposed to the extracts were used as a control group. The mitochondrial metabolism was assessed using the MTT assay and the cytokine release evaluated through MAGPIX. The degree of conversion of the adhesives was analyzed using FTIR (n = 5). The results were analyzed by ANOVA two-way and Tukey's test.
OBU and ZBU eluates caused a statistically significant reduction in mitochondrial metabolism, regardless of the LED used, indicating their cytotoxicity. In contrast, SBU did not significantly affect the MTT results, resembling the control group. A higher release of cytokines IL-1, IL-6, IL-10, and TNF-α were found in association to ZBU. SBU, on the other hand, increased the release of IL-8. OBU did not influenced the cytokine release. SBU presented the higher DC, while OBU and ZBU had similar DC, lower than SBU.
In conclusion, universal adhesives exhibit toxicity towards hDPSCs, but the extent of toxicity varies depending on the adhesive material. ZBU was associated with increased cytokine release, particularly pro-inflammatory mediators, from hDPSCs. The different LEDs did not influenced the cytotoxicity of the evaluated adhesives.
Water sorption, high volumetric shrinkage, polymerization stress, and potential estrogenic effects triggered by leached compounds are some of the major concerns related to BisGMA-TEGDMA co-monomer ...systems used in dental composites. These deficiencies call for the development of alternative organic matrices in order to maximize the clinical lifespan of resin composite dental restorations. This study proposes BisGMA-free systems based on the combination of UDMA and a newly synthesized diurethane dimethacrylate, and evaluates key mechanical and physical properties of the resulting materials.
2EMATE-BDI (2-hydroxy-1-ethyl methacrylate) was synthesized by the reaction between 2-hydroxy-1-ethyl methacrylate with a difunctional isocyanate (1.3-bis (1- isocyanato-1-methylethylbenzene) – BDI). The compound was copolymerized with UDMA (urethane dimethacrylate) at 40 and 60wt%. UDMA copolymerizations with 40 and 60wt% TEGDMA (triethylene glycol dimethacrylate) were tested as controls, as well as a formulation based in BisGMA (bisphenol A-glycidyl methacrylate)-TEGDMA 60:40% (BT). The organic matrices were made polymerizable by the addition of DMPA (2.2-dimethoxyphenoxy acetophenone) and DPI-PF6 (diphenyliodonium hexafluorophosphate) at 0.2 and 0.4wt%, respectively. Formulations were tested as composite with the addition of 70wt% inorganic content consisting of barium borosilicate glass (0.7μm) and fumed silica mixed in 95 and 5wt%, respectively. All photocuring procedures were carried out by a mercury arc lamp filtered to 320–500nm at 800mW/cm2. The experimental resin composites were tested for kinetics of polymerization and polymerization stress in real time. Flexural strength, elastic modulus, water sorption, and solubility were assessed according to ISO 4049. Biofilm formation was analyzed after 24h by luciferase assay. Data were statistically analyzed by one-way ANOVA and Tukey's test (α≤0.05).
In general, the addition of 2EMATE-BDI into the formulations decreased the maximum rate of polymerization (RPMAX), the degree of conversion at RPMAX (DC at RPMAX), and the final degree of conversion (final DC). However, these reductions did not compromise mechanical properties, which were comparable to the BT controls, especially after 7-day water incubation. The incorporation of 60wt% 2EMATE-BDI reduced water sorption of the composite. 2EMATE-BDI containing formulations showed reduction in polymerization stress of 30% and 50% in comparison to BT control and TEGDMA copolymerizations, respectively. Biofilm formation was similar among the tested groups.
The use of the newly synthesized diurethane dimethacrylate as co-monomer in dental resin composite formulations seems to be a promising option to develop polymers with low-shrinkage and potentially decreased water degradation.
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