The complex anatomy of teeth limits the accessibility and efficacy of regenerative treatments. Therefore, the application of well-known inducers as injectable hydrogels for the regeneration of the dentin-pulp complex is considered a promising approach. In this regard, this study aimed to develop an injectable hydrogel containing mineral trioxide aggregate (MTA). The injectable chitosan/oxidized-nanocrystalline cellulose/MTA (CS/OCNC/MTA) hydrogels were prepared, and the physicochemical properties of these hydrogels were evaluated by TGA, FTIR, Rheological analysis, and SEM. Moreover, the effect of MTA on the swelling and degradability of scaffolds was assessed. The proliferative effects of synthesized hydrogels were also determined on human dental pulp stem cells (hDPSCs) by MTT assay. For induction of differentiation and biomineralization in these cells, the alkaline phosphatase activity and Alizarin Red S staining tests were performed in the presence of fabricated scaffolds. The proliferation of hDPSCs was significantly increased in the presence of these hydrogels. Moreover, the addition of MTA to hydrogel structure dramatically improved the differentiation of hDPSCs. These results suggested that this novel injectable hydrogel provides appropriate physiochemical properties and can be considered a promising scaffold for regenerative endodontic procedures.
ABSTRACT Esterification of isoamyl alcohol with acetic acid was studied using different ion-exchange resins, namely Amberlyst 15 dry, Amberlyst 16 wet, Amberlite 120-IR. Esterification was carried out using different esterification methods that are quite new (ohmic, ultrasonic probe, and ultrasonic bath) and the results were compared with microwave-assisted esterification (MAE). The highest isoamyl acetate yield (99%) was obtained by MAE, using a mixture of acetic acid and isoamyl alcohol (mole ratio of 1:2) after 2?h of reaction time. In this process, 2% Amberlyst 15 dry was used. MAE had the least specific energy consumption (0.42?kWh/g isoamyl acetate) and specific CO2 emission (34?g/g isoamyl acetate). According to the images obtained by scanning electron microscopy, lower amounts of Amberlyst 15 dry beads were destroyed by MAE method compared to other esterification methods. In conclusion, MAE proved to be an economic and environmentally-friendly method for esterification of different flavoring compounds. 相似文献
Contact angle measurements with a large number of liquids on the semi-fluorinated acryl polymer EGC-1700 films are reported. The surface tension was determined to be gammasv=13.84 mJ/m2 from contact angles of octamethylcyclotetrasiloxane (OMCTS) and decamethylcyclopentasiloxane (DMCPS). Inertness of these two liquids makes them ideal for determination of surface tension of low-energy fluoropolymers. On the other hand, contact angles of many other liquids deviated somewhat from a smooth contact angle pattern that represents the EGC-1700 surface tension. It is argued that noninertness of the molecules of these liquids gives rise to specific interactions with the polymer film, causing the deviations. Furthermore, contact angles of a series of n-alkanes (n-hexane to n-hexadecane) showed systematic deviations from this curve, similar to the trend observed for n-alkanes/Teflon AF 1600 systems studied earlier. Adsorption of vapor of short-chain liquids onto the polymer film caused their contact angles to fall above the gammasv=13.84 mJ/m2 curve, and a parallel alignment of molecules of the long-chain n-alkanes in the vicinity of the solid was the explanation for the deviation of their contact angles below it. It is found that vapor adsorption effect is more significant in the case of Teflon AF 1600, while the alignment of liquid molecules close to the surface is more pronounced for EGC-1700. 相似文献
Applied Biochemistry and Biotechnology - Poplar wood hemicellulose prehydrolysate was used for microbial oil production using an oleaginous microorganism Cryptococcus curvatus. Initially, the... 相似文献
In this study, Co3O4 nanocatalysts were constructed in environmentally appropriate conditions using controlled, effective, and facile microwave method. The final nanostructures were characterized by SEM, XRD, and TEM analyses. The products had a small size distribution, homogeneous morphology, and crystallographic structures associated with the formation of Co3O4 nanostructures. Moreover, EDS mapping analysis confirmed the existence of Co and O elements in the final structure, and the magnetic properties of the samples were investigated by VSM. The application of this nanostructure in a catalytic process was further examined, and the results suggested that it could be used as a novel candidate for the synthesis of arylidene barbituric and Meldrum,s acid through Knoevenagel condensation of aldehydes by barbituric and Meldrum,s acid in aqueous media. The high yield of these nanocatalysts would be justified by the nature of the nanostructure as well as the experimental procedure developed in this study, which affected the physicochemical features of the products. 相似文献
Seven novel complexes (C1–C7) were synthesized by the interaction between Cu(I) metal cation, L1, L2, L3, X and PPh3, where L1–L3 are derivatives of ((pyridine-2-ylmethylene)amino)phenol imine ligands and X = Cl−, Br−, I−, NCS−. All the complexes were characterized using infrared, 1H NMR and 31P NMR spectroscopies. The crystal structures of C1–C7 were also determined using single-crystal X-ray diffraction. The organization of the crystal structures and the intermolecular interactions are discussed. The supramolecular assemblies are driven by cooperative π…π interactions and hydrogen bonds, followed by CH…π linkages. The potential anticancer effect of C1–C7 was assessed for human glioblastoma cells using several anticancer experiments, which showed that these complexes have marked anticancer property against U87 cells. It was also found that the minimum and maximum anticancer effects are shown by C3- and C4-treated samples, respectively. Furthermore, theoretical approaches were used to investigate the nature of metal–ligand interactions which suggest a closed-shell and electrostatic character for Cu…N, Cu…P and Cu…X bonds. 相似文献
Two new cobalt(III) complexes of the hexadentate ligand [1,4-bis[o-(pyridine-2-carboxamidophenyl)]-1,4-dithiobutane] (H2bpctb) with N4S2 donor set atoms have been synthesized. A reaction of Co(CH3COO)2·4H2O with (H2bpctb) leads to the formation of [CoIII(bpctb)]PF6 (1) having a CoN2(pyridine)N′2(amide)S2(thioether) coordination by symmetric bpctb2? ligand. A similar reaction under slightly different conditions, however, gives [CoIII(La)(Lb)] (2), resulting from a C–S bond cleavage reaction triggered by an acetate ion as a base, having CoN2(pyridine)N′2(amide)S(thioether)S′(thiolate) coordination. These two Co(III) complexes have been characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structures of [CoIII(bpctb)]PF6 (1) in the form of the solvate (1·MeOH·H2O) and of [CoIII(La)(Lb)] (2) have been determined by X-ray crystallography. The Co atoms of both complexes exhibit distorted octahedral geometry. The electrochemical investigation of [Co(bpctb)]PF6·MeOH·H2O (1·MeOH·H2O) and [CoIII(La)(Lb)] (2) by cyclic voltammetry reveals a reversible CoIII–CoII redox process at E1/2 = ?0.32 V (ΔEp = 80 mV); for 1, and E1/2 = ?0. 87 V (ΔEp = 70 mV) for 2. 相似文献
A series of novel N-heteroaryl α-arylglycines containing naphthol rings has been prepared by one-pot, three-component condensation reaction of glyoxalic acid, heteroaryl amines and naphthols in water at ambient temperature and under reflux conditions in moderate to high yields. The promising advantages such as removal of organic solvent, no need to catalyst, simplicity of the reaction procedure and easy product separation will be discussed in this article. 相似文献
The reaction of 2-amino-1-(2-propynyl)pyridinium bromide with various iodobenzenes, catalyzed by Pd-Cu, in the presence of sodium lauryl sulfate as the surfactant and cesium carbonate as the base, in water, leads to the formation of 2-substituted imidazo[1,2-α]pyridines. 相似文献