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1.
Electron. j. biotechnol ; 50: 1-9, Mar. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1292302

ABSTRACT

BACKGROUND: Phospholipase D (PLD) is used as the biocatalyst for phosphatidylserine (PS) production. In general, PLD was expressed in insoluble form in Escherichia coli. High-level soluble expression of PLD with high activity in E. coli is very important for industrial production of PLD. RESULTS: Streptomyces chromofuscus PLD coding gene was codon-optimized, cloned without signal peptide, and expressed in E. coli. The optimal recombinant E. coli pET-28a+PLD/BL21(DE3) was constructed with pET-28a without His-tag. The highest PLD activity reached 104.28 ± 2.67 U/mL in a 250-mL shake flask after systematical optimization. The highest PLD activity elevated to 122.94 ± 1.49 U/mL by feeding lactose and inducing at 20 C after scaling up to a 5.0-L fermenter. Substituting the mixed carbon source with 1.0 % (w/v) of cheap dextrin and adding a feeding medium could still attain a PLD activity of 105. 81 ± 2.72 U/mL in a 5.0-L fermenter. Fish peptone from the waste of fish processing and dextrin from the starch are both very cheap, which were found to benefit the soluble PLD expression. CONCLUSIONS: After combinatorial optimization, the high-level soluble expression of PLD was fulfilled in E. coli. The high PLD activity along with cheap medium obtained at the fermenter level can completely meet the requirements of industrial production of PLD.


Subject(s)
Phospholipases/metabolism , Streptomyces/enzymology , Solubility , Streptomyces/genetics , Temperature , Codon , Combinatorial Chemistry Techniques , Escherichia coli
2.
Article in Chinese | WPRIM | ID: wpr-879012

ABSTRACT

To evaluate the effects of Hydroxypropyl methylcellulose acetate succinate(HPMCAS MF) on absorption of silybin(SLB) from supersaturable self-nanoemulsifying drug delivery system which was pre-prepared at the early stage experiment. The cell toxicity of self-emulsifying preparation was evaluated by the MTT method, and the in vitro membrane permeability and absorption promoting effect of the self-emulsifying preparation were evaluated by establishing a Caco-2 cell monolayer model. The in vivo and in vitro supersaturation correlation was evaluated via the blood concentration of SLB. The results of MTT showed that the concentration of the preparation below 2 mg·mL~(-1)(C_(SLB) 100 μg·mL~(-1)) was not toxic to Caco-2 cells, and the addition of polymer had no significant effect on Caco-2 cells viability. As compared with the solution group, the transport results showed that the P_(app)(AP→BL) of the self-emulsifying preparation had a very significant increase; the transport rate of silybin can be reduced by polymer in 0-30 min; however, there was no difference in supersaturated transport between supersaturated SLB self-nanoemulsion drug delivery system(SLB-SSNEDDS) and SLB self-nanoemulsion drug delivery system(SLB-SNEDDS) within 2 hours. As compared with SLB suspension, pharmacokinetic parameters showed that the blood concentration of both SLB-SNEDDS and SLB-SSNEDDS groups were significantly increased, and C_(max) was 5.25 times and 9.69 times respectively of that in SLB suspension group, with a relative bioavailability of 578.45% and 1 139.44% respectively. C_(max) and relative bioavailability of SLB-SSNEDDS were 1.85 times and 197% of those of SLB-SNEDDS, respectively. Therefore, on the one hand, SSNEDDS can increase the solubility of SLB in gastrointestinal tract by maintaining stability of SLB supersaturation state; on the other hand, the osmotic transport process of SLB was regulated through the composition of its preparations, and both of them could jointly promote the transport and absorption of SLB to improve the oral bioavailability of SLB.


Subject(s)
Administration, Oral , Biological Availability , Caco-2 Cells , Drug Delivery Systems , Emulsions , Humans , Methylcellulose/analogs & derivatives , Nanoparticles , Particle Size , Silymarin , Solubility
3.
Braz. oral res. (Online) ; 35: e045, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1153603

ABSTRACT

Abstract The objective of this study was to evaluate the biocompatibility and mechanical properties of two commercially available and one experimental periodontal dressing materials. The cytotoxicity of Periobond ® , Barricaid ® and one experimental periodontal dressing based on Exothane ® 8 monomer was tested on 3T3/NIH mouse fibroblast. Genotoxicity was assessed by micronuclei formation, and cell alterations were analyzed using light microscopy. Both biological assays were performed using the eluate obtained from specimens after 24, 72, or 168 hours of incubation. Mechanical characterization was assessed through the ultimate tensile strength and the water sorption and solubility tests. The significance level of α = 0.05 was used for all statistical analyses. All the materials promoted a cell viability lower than 60% in all evaluated times. In general, the cell viability was significantly reduced after 72 and 168h of specimens' incubation. Considering the factor material, there were not statistical differences in the cell viability (p = 0.156). The genotoxicity was not statistically significant among the groups in the different periods of time (p > 0.05). Differences in the ultimate tensile strength values were not statistically significant different among the groups (p = 0.125). Periobond ® showed the higher water sorption values (p < 0.001). Regarding solubility, there were no statistical differences between the groups (p = 0.098). All the periodontal dressing materials evaluated in this study exerted a cytotoxic effect against mouse fibroblasts, and their toxicity became more evident over time. Among the materials evaluated, the experimental light-cure type has shown overall similar properties to the commercial references.


Subject(s)
Animals , Mice , Periodontal Dressings , Bandages , Solubility , Tensile Strength , Materials Testing
4.
Braz. oral res. (Online) ; 35: e018, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1142617

ABSTRACT

Abstract This study determined the effect of thiourethane-functionalized fillers (TU) on the antimicrobial properties, cytotoxicity, degree of conversion (DC), water sorption (Wsp) and solubility (Wsl) of experimental composites. TU-modified fillers were added at different ratios in experimental composites: 0 (Control-TU0), 25% (TU25), 50% (TU50), 75% (TU75) and 100wt% (TU100). The antimicrobial properties were detected through the exhaustion test and counting of Streptococus mutans colonies for biofilm formation. Cytotoxicity to human gingival fibroblasts was evaluated in three different parameters: XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide), NRU (Neutral Red Uptake assay) and CVDE (Crystal Violet Dye Exclusion test)) at the same cells. ELISA was used to measure the IL-6 and b-FGF biomarkers. DC was determined by Fourier-transformed infrared spectroscopy, while Wsp and Wsl by mass variations. Inhibitory capacity of biofilm formation was not observed for any material. All groups presented at least 70% of cell survival within the observed periods (24h and 7 days). Positive control (toxic) had high IL-6 values and low b-FGF values. No significant variations in DC, Wsp, and Wsl were observed among the experimental groups. The use of thiourethane did not present antimicrobial and cytotoxic activity and the tested materials presented equivalent properties to those conventionally used in dentistry.


Subject(s)
Humans , Water , Composite Resins/toxicity , Solubility , Materials Testing
6.
Electron. j. biotechnol ; 48: 86-94, nov. 2020. tab, graf, ilus
Article in English | LILACS | ID: biblio-1254836

ABSTRACT

BACKGROUND: Chinese hamster ovary (CHO) cells are the workhorse for obtaining recombinant proteins. Proteomic studies of these cells intend to understand cell biology and obtain more productive and robust cell lines for therapeutic protein production in the pharmaceutical industry. Because of the great importance of precipitation methods for the processing of samples in proteomics, the acetone, methanol-chloroform (M/C), and trichloroacetic acid (TCA)-acetone protocols were compared for CHO cells in terms of protein recovery, band pattern resolution, and presence on SDS-PAGE. RESULTS: Higher recovery and similar band profile with cellular homogenates were obtained using acetone precipitation with ultrasonic bath cycles (104.18 ± 2.67%) or NaOH addition (103.12 ± 5.74%), compared to the other two protocols tested. TCA-acetone precipitates were difficult to solubilize, which negatively influenced recovery percentage (77.91 ± 8.79%) and band presence. M/C with ultrasonic homogenization showed an intermediate recovery between the other two protocols (94.22 ± 4.86%) without affecting protein pattern on SDS-PAGE. These precipitation methods affected the recovery of low MW proteins (< 15 kDa). CONCLUSIONS: These results help in the processing of samples of CHO cells for their proteomic study by means of an easily accessible, fast protocol, with an almost complete recovery of cellular proteins and the capture of the original complexity of the cellular composition. Acetone protocol could be incorporated to sample-preparation workflows in a straightforward manner and can probably be applied to other mammalian cell lines as well.


Subject(s)
Animals , Recombinant Proteins , CHO Cells , Proteomics/methods , Acetone , Chemical Precipitation , Solubility , Trichloroacetic Acid , Cell Separation , Chloroform , Cell Culture Techniques , Methanol , Electrophoresis, Polyacrylamide Gel
7.
Braz. dent. j ; 31(5): 511-515, Sept.-Oct. 2020. tab
Article in English | LILACS, BBO | ID: biblio-1132334

ABSTRACT

Abstract This study aimed to assess the physicochemical properties of a repair material in the Brazilian market, BioMTA, in comparison to other two materials currently in use (Biodentine and MTA Angelus). The initial setting time was evaluated using Gillmore needle. The pH was measured with a pH-meter after 24 h, 3, 7, 14 and 21 days. The radiopacity was determined using the equivalence in millimeters of aluminum (mm Al) from digitized occlusal radiographs. Solubility was determined after immersion in water for 7 days. The data were analyzed by one-way ANOVA and Tukey tests (a=0.05). The BioMTA initial setting time (5.2 min) was lower than the other materials (p<0.05). All materials showed an alkaline pH at 21 days. At 24 h, BioMTA was the most alkaline material (p<0.05); and at 3, 7, 14 and 21 days there was no difference between BioMTA and Biodentine (p>0.05), both being more alkaline than MTA Angelus (p<0.05). The radiopacity of BioMTA (4.2 mm Al) was significantly higher compared to Biodentine (p<0.05) and lower than MTA Angelus (p<0.05). The solubility of the materials was -4.2%, -1.6% and 4.1% for BioMTA, MTA Angelus and Biodentine, respectively, with a significant difference between them (p<0.05). Therefore, it can be concluded that BioMTA displayed a shorter setting time, an alkaline pH, a higher radiopacity, and a gain in mass.


Resumo Este estudo teve como objetivo avaliar as propriedades físico-químicas de um material reparador disponível no mercado brasileiro, BioMTA, em comparação com outros dois materiais atualmente em uso (Biodentine e MTA Angelus). O tempo de presa inicial foi avaliado usando a agulha de Gillmore. O pH foi medido com um pH-metro após 24 h, 3, 7, 14 e 21 dias. A radiopacidade foi determinada aplicando a equivalência em milímetros de alumínio (mm Al) de radiografias oclusais digitalizadas. A solubilidade foi determinada após imersão em água por 7 dias. Os dados foram analisados ​​por meio dos testes ANOVA de uma via e Tukey (a=0,05). O tempo de presa inicial do BioMTA (5,2 min) foi menor do que os outros materiais (p<0,05). Todos os materiais apresentaram pH alcalino aos 21 dias. Às 24 h, o BioMTA foi o material mais alcalino (p<0,05); e aos 3, 7, 14 e 21 dias não houve diferença entre BioMTA e Biodentine (p>0,05), sendo ambos mais alcalinos que MTA Angelus (p<0,05). A radiopacidade do BioMTA (4,2 mm Al) foi significativamente maior em comparação ao Biodentine (p<0,05) e menor que o MTA Angelus (p<0,05). A solubilidade dos materiais foi de -4,2%, -1,6% e 4,1% para BioMTA, MTA Angelus e Biodentine, respectivamente, havendo diferença significativa entre eles (p<0,05). Portanto, pode-se concluir que o BioMTA apresentou um menor tempo de presa, pH alcalino, uma alta radiopacidade e um ganho em massa.


Subject(s)
Root Canal Filling Materials , Silicates , Oxides , Solubility , Acrylic Resins , Materials Testing , Brazil , Water , Calcium Compounds , Aluminum Compounds , Drug Combinations
8.
Con-ciencia (La Paz) ; 8(1): 121-131, 20200400. ilus.
Article in Spanish | LILACS | ID: biblio-1178619

ABSTRACT

INTRODUCCIÓN: el proceso de trazabilidad metrológica de un estándar secundario a uno primario es una propiedad del resultado de una medición o del valor de un estándar, por la cual se puede relacionar a referencias establecidas, usualmente nacionales o internacionales, a través de una cadena ininterrumpida de comparaciones, todas las cuales tienen incertidumbres determinadas. OBJETIVO: realizar la trazabilidad de un estándar secundario a uno primario de ciclosporina y de esta manera asegurar la calidad y pureza del mismo. MÉTODOS: se utilizaron los siguientes métodos: descripción organoléptica, solubilidad, identificación y cuantificación por Cromatografía Líquida de alta resolución (HPLC) en fase reversa. RESULTADOS: el estándar secundario de ciclosporina, cumplió con todas las especificaciones referidas a descripción organoléptica, solubilidad, identificación y se obtuvo una pureza de 97,5% utilizando un estándar primario cuyo título es de 98,5 %. CONCLUSIÓN: se realizó la trazabilidad metrológica de un estándar secundario a un estándar primario para poder utilizarlo como estándar de trabajo, garantizando el título del mismo. Esta propiedad es uno de los pilares para que los resultados de medida sean comparables entre sí, independientemente del lugar y tiempo en el que se hayan realizado, facilitando su aceptación universal y reduciendo las potenciales barreras técnicas al comercio.


INTRODUCTION: the metrological traceability process from a secondary standard to a primary one is a property of the result of a measurement or the value of a standard, by which it can be related to established references, usually national or international, through an uninterrupted chain of comparisons, all of which have certain uncertainties. OBJECTIVE: to carry out the traceability of a secondary standard to a primary one of cyclosporine and in this way to ensure its quality and purity. METHODS: the following methods were used: organoleptic description, solubility, identification and quantification by reversed phase High Performance Liquid Chromatogra- phy (HPLC). RESULTS: the secondary cyclosporine standard met all the specifications referred to organoleptic description, solubility, identification and a purity of 97.5% was obtained using a primary standard whose titer is 98.5%. CONCLUSION: the metrological traceability of a secondary standard to a primary standard was carried out in order to be able to use it as a working standard, guaranteeing its title. This property is one of the pillars for the measurement results to be comparable with each other, regardless of the place and time in which they have been carried out, facilitating their universal acceptance and reducing potential technical barriers to trade.


Subject(s)
Solubility , Weights and Measures , Cyclosporine , Methods
9.
Article in Chinese | WPRIM | ID: wpr-828411

ABSTRACT

Quercetin is a kind of typical flavonoid, mainly found in various vegetables, fruits and Chinese herbs that are consumed daily, with the functions of anti-oxidation, anti-tumor, prevention and treatment of cardiovascular and cerebrovascular diseases. Quercetin is a natural compound with defined anti-tumor activity. Due to its low bioavailability and poor water solubility, quercetin has limitations in clinical application. The quercetin derivatives with good solubility, high bioavailability, metabolic stability, and low toxicity have been obtained through modification of quercetin structure. In recent years, a large number of quercetin ethers, esters, complexes, C-4 carbonyloxy substituted derivatives, A,B-ring modified compounds and other derivatives have been synthesized and tested for in vitro anticancer activity. The quercetin derivatives with anti-tumor activity synthesized in the last 5 years were reviewed in this paper.


Subject(s)
Biological Availability , Humans , Neoplasms , Oxidation-Reduction , Quercetin , Solubility
10.
Article in Chinese | WPRIM | ID: wpr-828399

ABSTRACT

In order to improve the supersaturation and maintenance time of drug dispersion in curcumin self-nanoemulsion(CUR-SNEDDS), precipitation inhibitors(PPIs) were introduced to prepare curcumin supersaturated self-emulsion(CUR-SSNEDDS). The composition of CUR-SNEDDS prescriptions was selected through the solubility test, the compatibility of oil phase and surfactant, the investigation of the emulsifying ability of the surfactant and the drawing of the pseudo-ternary phase diagram. Analytic hierarchy process was used in combination with central composite design-response surface method to optimize the prescription. The type and dosage of precipitation inhibitors(PPIs) were selected to maintain the supersaturated concentration and duration of CUR in artificial gastrointestinal fluids. At the same time, polarizing microscope was used to evaluate the crystallization inhibition effect and the quality and in vitro release behavior of CUR-SSNEDDS. The prepared CUR-SSNEDDS prescription was capryol 90-kolliphor RH40-transcutol HP-Soluplus(7.93∶66.71∶25.36∶5), with the drug loading of(65.12±1.25) mg·g~(-1). CUR-SSNEDDS was transparent yellow, and the nanoemulsion droplets were spherical with uniform distribution. The emulsification time was(21.02±0.13) s, the average particle size was(57.03±0.35) nm, the polydispersity index(PDI) was(0.23 ± 0.01), and the Zeta potential was(-18.10±1.30) mV. CUR-SSNEDDS significantly inhibited the generation and growth of crystals after in vitro dilution. The supersaturation could be maintained above 10 within 2 h, and the dissolution rate and degree of CUR in artificial gastrointestinal fluid were significantly increased. Soluplus could effectively maintain the supersaturated state of CUR and enhance CUR dissolution in vitro.


Subject(s)
Biological Availability , Curcumin , Emulsions , Nanoparticles , Particle Size , Solubility , Surface-Active Agents
11.
Article in Chinese | WPRIM | ID: wpr-828005

ABSTRACT

This study aimed to prepare evodiamine-glycyrrhizic acid(EVO-GL) micelles to enhance the anti-hepatic fibrosis activity of evodiamine. Firstly, EVO-GL micelles were prepared with use of thin film dispersion method. With particle size, encapsulation efficiency, loading capacity of micelles and the solubility of evodiamine as the indexes, the effect of different factors on micelles was observed to screen the optimal preparation methods and process. Then the pharmaceutical properties and the therapeutic effects of EVO-GL micelles prepared by optimal process were evaluated on CCl_4-induced hepatic fibrosis. The results showed that the micelles prepared by the thin film dispersion method had an even size, with an average particle size of(130.80±12.40)nm, Zeta potential of(-41.61±3.12) mV, encapsulation efficiency of 91.23%±1.22%, drug loading of 8.42%±0.71%, high storage stability at 4 ℃ in 3 months, and slow in vitro release. Experimental results in the treatment of CCl_4-induced hepatic fibrosis in rats showed that EVO-GL micelles had a synergistic anti-hepatic fibrosis effect, which significantly reduced the liver function index of hepatic fibrosis rats. In conclusion, the EVO-GL micelles prepared with glycyrrhizic acid as a carrier would have a potential application prospect for the treatment of hepatic fibrosis.


Subject(s)
Animals , Drug Carriers , Glycyrrhizic Acid , Liver Cirrhosis , Micelles , Particle Size , Quinazolines , Rats , Solubility
12.
Article in Chinese | WPRIM | ID: wpr-828889

ABSTRACT

OBJECTIVE@#To develop a fast, sensitive and cost-effective method based on resonance light scattering (RLS) for characterization of protein solubility to facilitate detection of changes in solubility of mutant proteins.@*METHODS@#We examined the response curve of RLS intensities to the protein concentrations in synchronous scanning mode. The curve intersection points were searched to predict the maximal concentrations of the protein in dispersion state, which defined the solubility of the protein in this given state. Bovine serum albumin (BSA, 0-50 g/L) was used as the model to investigate the influences of pH values (6.5, 7.0, and 7.4) and salt concentrations (0.05, 0.10, 0.15, and 0.20 mol/L) on the determined solubility. The solubility of glutathione S-transferase isoenzymes alpha (GSTA, 0-27.0 g/L) and Mμ (GSTM, 0-20.0 g/L) were estimated for comparison. The RLS-based method was used to determine the solubility of uricase (MGU, 0-0.4 g/L) to provide assistance in improving the solubility of its mutants.@*RESULTS@#We identified two intersection points in the RLS response curves of the tested proteins, among which the lower one represented an approximation of the maximal concentration (or the solubility of the protein) in single molecular dispersion, and the higher one the saturated concentration of the protein in multiple molecular aggregation. In HEPES buffer, the two intersection points of BSA (isoelectric point 4.6) both increased with the increase of pH (6.5-7.4), and their values were ~1.2 g/L and ~33 g/L at pH 7.4, respectively; the latter concentration approached the solubility of commercial BSA in the same buffer at the same pH. The addition of NaCl reduced the values of the two intersection points, and increasing salt ion concentration decreased the values of the lower intersection points. Further characterizations of GSTA and GSTM showed that the low concentration intersection points of the two proteins were ~0.7 g/L and ~0.8 g/L, and their high concentration intersection points were ~10 g/L and ~11 g/L, respectively, both lower than those of BSA, indicating the feasibility of the direct characterization of protein solubility by RLS. The two concentration intersection points of MGU were 0.24 g/L and 0.30 g/L, respectively, and the low concentration intersection point of its selected mutant was increased by 2 times.@*CONCLUSIONS@#RLS allows direct characterization of the solubility of macromolecular proteins. This method, which is simple and sensitive and needs only a small amount of proteins, has a unique advantage for rapid comparison of solubility of low-abundance protein mutants.


Subject(s)
Hydrogen-Ion Concentration , Light , Scattering, Radiation , Solubility , Spectrum Analysis
13.
Article in Chinese | WPRIM | ID: wpr-878861

ABSTRACT

To prepare and optimize the self-microemulsion co-loaded with tenuifolin and β-asarone(TF/ASA-SMEDDS) and evaluate its quality. The prescription compositions of TF/ASA-SMEDDS were screened by solubility test, single factor test and pseudo-tern-ary phase diagram, and the prescriptions were further optimized by Box-Behnken response surface method, with the drug loading and particle size as the evaluation indexes. Then the optimized TF/ASA-SMEDDS was evaluated for emulsified appearance, particle size, morphology and drug release in vitro. The optimized prescription for TF/ASA-SMEDDS was as follows: caprylic citrate triglyceride polyoxyethylene castor oil-glycerol(10.8∶39.2∶50), drug loading of(5.563±0.065) mg·g~(-1) for tenuifolin and(5.526±0.022) mg·g~(-1) for β-asarone; uniform and transparent pan-blue nanoemulsion can be formed after emulsification, with particle size of(28.84±0.44) nm. TEM showed that TF/ASA-SMEDDS can form spherical droplets with a uniform particle size after emulsification; In vitro release test results showed that the drug release rate and cumulative release of tenuifolin and β-asarone were significantly improved. The preparation process of TF/ASA-SMEDDS was simple and can effectively improve in vitro release of tenuifolin and β-asarone.


Subject(s)
Anisoles , Biological Availability , Diterpenes, Kaurane , Drug Delivery Systems , Emulsions , Particle Size , Solubility , Surface-Active Agents
14.
Article in Chinese | WPRIM | ID: wpr-878787

ABSTRACT

To prepare a new dosage form that can improve the drug loading of the film--ginkgolide B nanosuspension lyophilized powder orodispersible film(GB-NS-LP-ODF) and to evaluate its quality. Firstly, ginkgolide B nanosuspension(GB-NS) was prepared by media milling method, and then ginkgolide B nanosuspension lyophilized powder(GB-NS-LP) was prepared with freeze-drying method. The mannitol was used as lyoprotectant and its dosage was also investigated. GB-NS-LP-ODF was prepared by solvent casting method and its formulation was screened by single factor test method and optimized by orthogonal test. The appearance, mechanical properties, content uniformity and in vitro dissolution of the optimized GB-NS-LP-ODF were investigated. The particle size of prepared GB-NS was about 201 nm, and the optimal dosage of mannitol was 8%. According to the optimal formula, the GB-NS-LP-ODF was prepared with GB-NS-LP 35.6%, PVA 0588 49.4%, PEG 400 10.7% and CMS-Na 4.3%, and completely disintegrated in about 30 s, and the particle size of reconstituted GB nanoparticles from ODF was about 210 nm. The film with smooth appearance and good mechanical properties was stable within 30 days and the content uniformity(A+2.2 S<15) conformed to the regulations. Scanning electron microscope(SEM) showed that GB-NS-LP-ODFs were evenly distributed and the particle size was about 200 nm. X-rays diffraction(XRD) showed that its crystallinity was significantly lower than that of GB raw drug and GB-ODF. The results of in vitro release test showed that the drug film was completely dissoluted within 10 minutes. These results indicated that nanosuspension lyophilized powder was prepared by freeze drying of nanosuspensions, and then loaded into the orodispersible film to effectively increase the drug loading of the ODF and have broad application prospects.


Subject(s)
Ginkgolides , Lactones , Nanoparticles , Particle Size , Powders , Solubility , Suspensions
15.
Braz. arch. biol. technol ; 63: e20180292, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132184

ABSTRACT

Abstract Acetylated cassava starch with low and medium degrees of substitution (DS) were synthesized. Also, the effect of DS on swelling power, solubility, morphological properties, gelatinization temperature, paste clarity and moisture sorption were studied. Swelling power and solubility in water between 50ºC and 90°C were determined. Acetylated cassava starches with low DS showed an increased in both parameters, while at higher DS values a reduction of them was observed. Maximum swelling power values were measured in acetylated starch with DS of 0.2 and maximum solubility was registered at DS of 0.72. Equilibrium moisture content values from sorption isotherms presented a good fit using the GAB model (R2>0.96). SEM micrographs showed that as acetyl groups are incorporated the granules suffer surface changes and eventually lose their structure at DS of 1.5. Clarity of acetylated starch pastes with low DS was lighter than native starch paste. In addition, the increase in DS produced a reduction in gelatinization temperature.


Subject(s)
Acetylation , Solubility , Substantia Gelatinosa , Temperature , Starch and Fecula , Microscopy, Electron, Scanning
16.
Braz. j. oral sci ; 19: e201704, jan.-dez. 2020. ilus
Article in English | LILACS, BBO | ID: biblio-1116338

ABSTRACT

Aim: The aim of this study was to evaluate the influence of the translucency of ceramic on water sorption and solubility of resin cements over time. Methods: Lithium disilicate ceramic slides (15x15x1 mm), A1 in color and with different translucencies (high-medium-low) were manufactured; and a glass slide with similar dimension was used as control. Under every slide, 15 specimens (8x0.5 mm) from each resin cement were prepared: light-cured (RelyX Veneer); conventional dual-cured (RelyX ARC); and self-adhesive dual-cured (Rely-X U200). The specimens were then sub-divided according to the period of evaluation (immediately, after 6 and 12 months of storage) (n=5). To evaluate the loss or gain of mass, the specimens were dried until a constant mass was reached. Subsequently, they were divided according to the respective period of storage at 37°C in distilled water and weighed immediately following removal from water. After each period, specimens underwent a new dehydration. Values from water sorption and solubility were calculated and statistically analyzed (Anova 3-way/Tukey test). Results: The lower translucency resulted in greater water sorption and solubility for all cements, regardless of the experimental period. The self-adhesive dual-cured cement showed higher water sorption under all experimental periods and had worse values after 1 year aging. Differences among solubility could only be detected after aging, and the light-cured material had higher values after 6 and 12 months. Conclusions: It could be concluded that the low degree of translucency can negatively influence the passage of light and interfere on the durability of the resin cement. The conventional dual-cured resinous agent seemed to be less affected by such condition


Subject(s)
Solubility , Ceramics , Dental Restoration, Permanent , Self-Curing of Dental Resins
17.
Braz. j. oral sci ; 19: e201715, jan.-dez. 2020. ilus
Article in English | LILACS, BBO | ID: biblio-1116536

ABSTRACT

Aim: Little is known about the reparability of glass ionomer cements (GICs) after storage in acid environments. The aim of this study was to evaluate the solubility and repairability of GICs immersed in acid solutions and subjected to brushing. Methods: Thirty discs of each GIC (Vitremer, VitroFil LC, VitroFil, and Maxxion R) were divided into three immersion groups: distilled water, Coca-Cola, or hydrochloric acid (HCl), then subjected to brushing. The weight of discs was measured before and after the immersions to determine mass alteration. Each disc was repaired, by adding the same brand of GIC over its surface. After immersing the repaired specimens in same solutions, shear bond strengths using universal testing machine were measured. Two-way ANOVA and Tukey's test was used (α=0.05). Results: Resin-modified GICs degrade after HCl immersion followed by brushing (p<0.05), while self-cured GICs were negatively affected by all challenges (p<0.05). The challenges decreased the repair strength for VitroFil LC (p<0.05), which had higher repair shear bond strength than the other GICs (p<0.05), exhibiting most cohesive failures. Conclusion: Self-cured GICs degraded when immersed in all acid solutions with brushing while resin-modified GICs only degraded following HCl immersion with brushing. Despite exhibiting the best repair results, VitroFil LC was the only GIC that was influenced by all the acid challenges


Subject(s)
Solubility , Surface Properties , Materials Testing , Shear Strength , Glass Ionomer Cements
18.
Arq. odontol ; 56: 1-6, jan.-dez. 2020. tab
Article in Portuguese | LILACS, BBO | ID: biblio-1103991

ABSTRACT

Objetivo: Analisar as propriedades físico-químicas, escoamento, tempo de presa, solubilidade e alteração dimensional, dos cimentos endodônticos à base de óxido de zinco e eugenol: Endomethasone N, Endofill e Grosmann, de acordo com a especificação número 57 da American Dental Association. Métodos: Realizou-se os testes nas condições ambientais de 23° ± 2°C e 50 ± 5% de umidade relativa do ar, mantidas 48 h antes dos procedimentos, repetindo-se cinco vezes e obtendo-se uma média aritmética. Resultados: Os cimentos à base de óxido de zinco e eugenol analisados apresentaram tempo de endurecimento elevados, para o teste de escoamento, o Endofill e Grossman apresentaram-se acima do estabelecido. Em relação à solubilidade, o Endomethasone N esteve dentro do padrão e os demais cimentos excederam. Conclusão:Todos os cimentos analisados obtiveram valores diferentes do recomendado para alteração dimensional. Nenhum dos cimentos enquadrou-se completamente nas normatizações.


Aim: To analyze the physical-chemical properties, flow, setting time, solubility and dimensional change of endodontic cements, based on zinc oxide and eugenol: Endomethasone N, Endo fill, and Grosmann, according to specification number 57 of the American Dental Association. Methods: The tests were conducted under environmental conditions of 23° ± 2°C and 50 ± 5% relative air humidity, maintained for 48 h prior to the procedures, repeating five times and obtaining an arithmetic mean. Results: The cements based on zinc oxide and eugenol analyzed in this study showed high hardening times. For the flow test, Endo fill and Grossman were above the established parameters. Regarding solubility, Endomethasone N was within the standard, while the other cements exceeded this standard. Conclusion: All analyzed cements obtained values that proved to be different from those recommended for dimensional changes. None of the cements were completely compliant with the regulations.


Subject(s)
Solubility , Zinc Oxide-Eugenol Cement , Materials Testing , Physical and Chemical Properties , Dental Cements , Zinc Oxide , Eugenol
19.
Rev. Soc. Odontol. La Plata ; 29(57): 15-19, dic. 2019. ilus
Article in Spanish | LILACS | ID: biblio-1049929

ABSTRACT

Se determinó la solubilidad en agua en ensayos in-vitro de un sellador para uso endodóntico a base de un conglomerado de trióxidos minerales (MTA), marca Endosealer® (Densell SA) de acuerdo a la norma UNE-EN ISO 6876:2012. En el ensayo de solubilidad en agua durante 24 hs se encontró pérdida de masa (3,3 %) y la presencia de sólidos en las aguas de lavado (6,4 %). Esto indica que durante el ensayo ocurre la solubilización de parte del material y la incorporación de agua, lo que no permite establecer un valor real de la solubilidad.(AU)


Solubility of a commercial endodontic sealer (Endosealer® (Densell SA)) was performed according to the UNE-EN ISO 6876:2012. The results show a mass loss of 3.3 % and 6.4 % of solid in the test solution. These indicate that during the solubility test part of the material solubilizes and an actual value of solubility cannot feasible be determined


Subject(s)
Root Canal Filling Materials , Dental Cements/analysis , Dental Cements/chemistry , Solubility , Dental Materials
20.
Braz. dent. j ; 30(4): 368-373, July-Aug. 2019. tab, graf
Article in English | LILACS | ID: biblio-1011563

ABSTRACT

Abstract The aim of this study was to evaluate physical properties of endodontic sealers (AH Plus, MTA Fillapex and Endofill), by conventional and micro-CT tests. Dimensional stability was evaluated after immersion of materials in distilled water for 30 days. Solubility and volumetric change were evaluated after 7 and 30 days of immersion in distilled water. Solubility was evaluated by means of mass loss and volumetric change was assessed by micro-CT. Porosity was evaluated under a microscope after 7 days of immersion in distilled water, and by using micro-CT after setting and immersion in distilled water for 7 and 30 days. Statistical analysis was performed by ANOVA and Tukey's test with 5% significance level. MTA Fillapex presented the highest solubility (p<0.05), showing values above the ISO/ADA recommendations. MTA Fillapex presented higher volumetric and dimensional changes, followed by Endofill and AH Plus (p<0.05). Dimensional stability of the MTA Fillapex and AH Plus did not follow ISO/ADA standards. The highest total porosity was observed for MTA Fillapex (p<0.05). Endofill had higher total porosity than AH Plus according to microscope evaluation (p<0,05), and both sealers were similar in micro-CT assessment (p>0,05). In conclusion, MTA Fillapex presented higher solubility, dimensional and volumetric change besides porosity compared to the other evaluated sealers. The assessed physical properties of sealers are related, and the different tests provided complementary data. Micro-CT is a valuable method for assessment of physical properties of endodontic materials.


Resumo O objetivo deste estudo foi avaliar propriedades físicas de cimentos endodônticos (AH Plus, MTA Fillapex e Endofill), por meio de testes convencionais e micro-CT. A estabilidade dimensional foi avaliada após imersão dos materiais em água destilada por 30 dias. A solubilidade e a alteração volumétrica dos materiais foram avaliadas após 7 e 30 dias de imersão em água destilada. A solubilidade foi avaliada por meio de perda de massa e a alteração volumétrica foi avaliada por micro-CT. A porosidade foi avaliada por microscopia após 7 dias de imersão em água destilada e por micro-CT após a presa e imersão em água destilada por 7 e 30 dias. A análise estatística foi realizada por meio dos testes ANOVA e Tukey, com nível de significância de 5%. MTA Fillapex apresentou a maior solubilidade (p<0,05), com valores acima das recomendações ISO/ADA. As alterações volumétricas e dimensionais foram maiores para MTA Fillapex, seguido por Endofill e AH Plus (p<0,05). MTA Fillapex e AH Plus não cumpriram os padrões ISO/ADA em relação à estabilidade dimensional. Uma maior porosidade total foi observada para MTA Fillapex (p <0,05). Endofill apresentou maior porosidade total que o AH Plus pela avaliação em microscopia (p<0,05), e ambos os cimentos foram semelhantes na avaliação por micro-CT (p>0,05). Em conclusão, MTA Fillapex apresentou maior solubilidade, alteração dimensional e volumétrica, além de maior porosidade em relação aos demais cimentos avaliados. As propriedades físicas avaliadas estão relacionadas, e os diferentes testes forneceram dados complementares. Micro-CT é um método valioso para avaliação das propriedades físicas dos materiais endodônticos.


Subject(s)
Root Canal Filling Materials , Oxides , Solubility , Materials Testing , Water , Porosity , Calcium Compounds , Drug Combinations , Epoxy Resins , X-Ray Microtomography
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