Effect of dexamethasone on levels of inflammatory factors and EGF mRNA in rabbits suffering from oral ulcers

Purpose: To investigate the therapeutic effect of dexamethasone on rabbits suffering from oral ulcers, and the underlying mechanism(s) of action. Methods: A rabbit model of oral ulcer was established by applying 40 % glacial acetic acid solution to the oral buccal membranes of the animals. Three groups of rabbits were used. Changes in area of the oral ulcer were recorded after dexamethasone administration. Levels of epidermal growth factor (EGF) were assayed using reverse transcription PCR (RT-PCR), while MDA levels and expression levels of IL- 6, IL-8 and TNF-α were determined by enzyme-linked immunosorbent assay (ELISA). Local histopathological changes were examined histologically with the aid of hematoxylin and eosin (H & E) staining. Results: There were reductions in ulcer areas in group C on the 2nd, 4th and 7th days of dexamethasone administration, when compared with group B (p < 0.05). The EGF levels in the buccal mucosa of rabbits in groups B and C were significantly higher than those in group A (p < 0.05), while the highest EGF level was in group C (p < 0.05). The levels of MDA, IL-6, IL-8, and TNF-α significantly increased in groups B and C (p < 0.05). Results from H & E staining showed lower levels of inflammatory cells in group C than in group B, with visible proliferation of fibroblast cells and epithelial cells in group C after dexamethasone administration. Conclusion: Dexamethasone accelerates healing of oral ulcer by regulating EGF levels. This finding provides a new approach to the treatment of oral ulcers.

Complete mineralization of acetic acid using catalytic ozonation with a high energy efficiency enhanced by MnO2/γ-Al2O3

The complete mineralization of acetic acid in a biodegradation process is difficult due to the α-position methyl on the carboxyl group of acetic acid. This study explores the complete oxidation of acetic acid by catalytic ozonation. Metal oxides of MnO2, Co3O4, Fe3O4, and CeO2 loaded on γ-Al2O3 power were used as the catalysts. The experimental results showed that MnO2/γ-Al2O3 catalyst had the best mineralization performance for acetic acid. Typically, the mineralization of acetic acid is as high as 88.4% after 300 min ozonation of 100 mL of 1.0 g L‒1 acetic acid catalysed by 3.0 g 1.0wt.% MnO2/γ-Al2O3 catalyst powder with an energy efficiency of 15 g kWh‒1. However, without a catalyst, the mineralization of acetic acid is only 33.2% with an energy efficiency of 5.1 g kWh−1. The effects of MnO2 loading, catalyst dosage, acetic acid concentration, O3 concentration, ozonation temperature, and initial pH value of the acetic acid solution were systematically investigated. Radical quenchers and in-situ DRIFTS analyses indicated that •OH radical and reactive oxygen species on catalyst surface played an important role in the ozonation of acetic acid to CO2 and H2O. The mechanism of acetic acid oxidation on MnO2/γ-Al2O3 is proposed.

Etched 3D-Printed Polycaprolactone Constructs Functionalized with Reduced Graphene Oxide for Enhanced Attachment of Dental Pulp-Derived Stem Cells

A core challenge in the field of tissue engineering is the ability to establish pipeline workflows for the design and characterization of scaffold technologies with clinically translatable attributes. The parallel development of biomaterials and stem cell populations represents a self-sufficient and streamlined approach for establishing such a pipeline. In the current study, rat dental pulp stem cell (rDPSC) populations were established to assess functionalized polycaprolactone (PCL) constructs. Initial optimization and characterization of rDPSC extraction and culture conditions confirmed that cell populations were readily expandable and demonstrated surface markers associated with multi-potency. Subset populations were transduced to express DsRed fluorescent protein as a mechanism of tracking both cells and cell-derived extracellular matrix content on complex scaffold architecture. Thermoplastic constructs included reduced graphene oxide (rGO) as an additive to promote cellular attachment and were further modified by surface etching a weak acetic acid solution to roughen surface topographical features, which was observed to dramatically improve cell surface coverage in vitro. Based on these data, the modified rGO-functionalized PCL constructs represent a versatile platform for bone tissue engineering, capable of being applied as a standalone matrix or in conjunction with bio-active payloads such as DPSCs or other bio-inks.

FORMULATION AND CHARACTERIZATION OF SERUM COLLAGEN OF SEA CUCUMBER EXTRACT STICHOPUS HORRENS AS AN ANTIOXIDANT

Objective: The study was aimed to extract, formulate and characterize collagen extract of Stichopus horrens into serum preparations and decide antioxidant activity in powders and serum preparations. Methods: The sea cucumber meat was extracted collagen in three stages, namely the pretreatment stage using 0.3 M NaOH solution 1:10 (w/v) for 48 h, the hydrolysis step in the 0.3 M 1:10 acetic acid solution (w/v) for 48 h, and the extraction stage with distilled water 1: 2 (w/v) for 2 h at 45 °C. The collagen extract was freeze-dried to obtain collagen powder. Collagen powder was characterized by HPLC and its antioxidant activity was determined using the DPPH method. Collagen powder formulated with extract variation of 0, 0.5 and 1%. Evaluation of serum included organoleptic, homogeneity, stability of pH and viscosity as well as antioxidant activity. Results: The results showed that collagen powder had a % yield of 0.24%, which consisted of the amino acids glycine, proline, alanine, and glutamic acid as the dominant amino acids. The % Free radical inhibition of collagen powder at concentration of 5000 ppm was 63.23%. IC50 values were obtained at 4045.37 ppm. The stability test resulted in stable serum preparations without significant changes at 4 °C and 27 °C±2 °C storage temperatures. Conclusion: The measurement of DPPH Radical reduction activity in the highest serum preparation was 1% extract with a value of 2.4%.

Bio-Based Epoxy Adhesives with Lignin-Based Aromatic Monophenols Replacing Bisphenol A

A bio-epoxy surface adhesive for adherence of the metal component species to glass substrate with desirable adhesion strength, converted controlled removal upon request, and bio-based resource inclusion was developed. For the development of resin, three different lignin-based aromatic monophenols, guaiacol, cresol, and vanillin, were used in the chemical epoxidation reaction with epichlorohydrin. The forming transformation process was studied by viscoelasticity, in situ FTIR monitoring, and Raman. Unlike other hydroxyl phenyls, guaiacol showed successful epoxide production, and stability at room temperature. Optimization of epoxide synthesis was conducted by varying NaOH concentration or reaction time. The obtained product was characterized by nuclear magnetic resonance and viscosity measurements. For the production of adhesive, environmentally problematic bisphenol A (BPA) epoxy was partially substituted with the environmentally acceptable, optimized guaiacol-based epoxy at 20, 50, and 80 wt.%. Mechanics, rheological properties, and the possibility of adhered phase de-application were assessed on the bio-substitutes and compared to commercially available polyepoxides or polyurethanes. Considering our aim, the sample composed of 80 wt.% bio-based epoxy/20 wt.% BPA thermoset was demonstrated to be the most suitable among those analyzed, as it was characterized by low BPA, desired boundary area and recoverability using a 10 wt.% acetic acid solution under ultrasound.

The oxidation of 4-bromacetophenone by ozone in acetic acid

The kinetics and mechanism of oxidation of 4-bromoacetophenone by ozone in acetic acid solution have been studied. It was shown that 77% of the starting material is oxidized by the benzene ring; 8% of 4-bromobenzoic acid and small amounts of carbon (IV) oxide were identified among the side chain ozonation products. The main reaction products are aliphatic peroxide compounds, which have in their structure one hydroperoxide group. Manganese (II) acetate was shown to be the most effective catalyst for the side chain reaction of 4-bromoacetophenone in acetic acid. High selectivity for the side chain is achieved only at sufficiently high concentrations of catalyst ([Mn(OAc)2]0:[ArH]0=1:4). The main product of the catalytic oxidation of 4-bromoacetophenone is 4-bromobenzoic acid with a yield of 82.5%. The found dependences of the rate of oxidation of 4-bromoacetophenone by ozone on the concentration of reactants are described by the kinetic equation of the third order, the reaction rate has the first order with respect to each reagent. It was found that the decisive role in the selective oxidation of 4-bromoacetophenone is played by two-stage oxidation, in which ozone predominantly reacts with the reduced form of manganese, and the introduction of the substrate into side chain oxidation is carried out by the reaction with the oxidized form of metal. According to the research results, the mechanism of catalytic ozonation of 4-bromoacetophenone in acetic acid has been proposed, which involves ion-radical non-chain oxidation of the substrate.

FORMULATION AND IN VITRO EVALUATION OF CHITOSAN FILMS CONTAINING LINEZOLID FOR THE TREATMENT OF PERIODONTITIS

The study was aimed to formulate a dental film containing linezolid, a broad spectrum antimicrobial agent which could be easily placed into the periodontal pocket and be capable of delivering therapeutic concentrations of drug for prolonged periods and also reducing the side effects. In the present investigation, chitosan strips containing linezolid in three different concentrations (10, 20, and 30 %w/w with respect to the weight of polymer) were prepared by the solvent casting method, by using 1 %V/V acetic acid solution. The prepared formulations were evaluated for various properties such as weight variation, thickness, folding endurance, moisture loss, tensile strength, in vitro release, release kinetic study and stability studies. The weight variation and thickness were found to be in the range of (0.99-1.58 mg) and (0.92-1.76 mm), the moisture content, folding endurance was found to be maximum for the plain film and minimum for the drug containing formulation. The tensile strength was found to be in the range of (2.44-1.43 kg/ mm2 ) for the formulation. The dissolution studies showed a burst release initially followed by a progressive fall in the release of the drug (91.15 - 95.87 %) and the release kinetics followed the zero-order pattern. The short term stability studies were conducted and there were no significant changes observed. Hence, low dose, site-specific linezolid film is a potential tool for the treatment of periodontitis.

Research on adsorption of Cd2+ by hydroxyapatite/chitosan nanocomposite

Hydroxyapatite/chitosan nanocomposite (n-HAp/ChS) was synthesized successfully from 0.5 M Ca(NO3)2 + 5 % chitosan/2 % acetic acid solution and 0.3 M (NH4)2HPO4 solution at pH 10-11 using 28 % NH3 solution by chemical precipitation method. n-HAp/ChS was used for the adsorption of Cd2+ from aqueous solution. The effect of factors on the Cd2+ adsorption efficiency and capacity was investigated. The adsorption efficiency and capacity obtained 97,75 % and 58,65 mg/g respectively at suitable condition: pH0 5.9,n-HAp/ChS mass of 0.1 g, initial Cd2+ concentration of 60 mg/L, contact time 40 minutes at room temperature (30oC). The experimental data was described by Langmuir and Freundlich isotherm models.

LC-ESI-tandem MS and in silico ADMET analysis of polyphenols from Rhus coriaria L. and Micromeria fruticosa (L.) Druce ssp. brachycalyx P. H. Davis

Background Micromeria fruticosa (L.) Druce ssp. brachycalyx P. H. Davis and Rhus coriaria L., which are Lamiaceae species, are used both as spices in food and medicinally. Lamiaceae species are known to contain high amounts of polyphenols. In this study, liquid chromatography–quadrupole time-of-flight–tandem mass spectrometry (LC-QTOF-MS/MS) was used for analysis of polyphenols in the plants. Under gradient elution with using 0.1% aqueous acetic acid solution and acetonitrile mobile phases, an Agilent Poroshell C18 reversed phase column was used for the simultaneous determination of 18 polyphenols, and separation was performed in 30 min. Pharmacokinetic properties of these polyphenols such as drug-like and toxicity were estimated using open-source software, pkCSM and SwissADME. Results These compounds were determined to represent different classes of polyphenols, including phenolic acids, flavonoids, coumarin and tannins. ADMET predictions of polyphenols indicated that these compounds are easily absorbed and do not have toxic effects. Conclusion While the Rhus coriaria L. includes anthocyanidins, tannins, phenolic acid and flavonoids, the Micromeria fruticosa (L.) Druce ssp. brachycalyx P. H. Davis has phenolic acid, coumarin and flavonoids, according to these results. In silico ADME/Tox predictions revealed that these bioactive components are to be drug-like and non-mutagenic. These data are supportive for future analysis that can lead to their therapeutic use of the plants, suggesting that this species may be used as a natural medicinal source in the future after detailed analysis tests. Graphical abstract

Ethanol concentration of Kombucha teas in British Columbia, Canada

Kombucha is a sweetened tea beverage fermented by bacterial and yeast cultures. Sweeteners such as glucose, sucrose, fructose and others are converted by yeasts into ethanol, then by Acetobacter and other bacterial species into a weak acetic acid solution that is diluted, flavoured and packaged into glass or aluminum cans for consumer consumption. Naturally, fermented Kombucha contains 0 to 3% alcohol-by-volume (ABV). However, Kombucha containing ethanol is concerning for pregnant women and young children for whom low levels of ethanol consumption (&lt;3% ABV) create adverse medical outcomes. In the province of British Columbia (BC), Canada beverages containing &gt;1% ABV are regulated as liquor. This study assessed ethanol concentrations in Kombucha collected from processors and purchased at retail venues in BC. Ethanol values were compared to the place of manufacture (country or province) and place of purchase (grocery stores, restaurants, farmers markets, recreational centres, and processors). Ethanol (n = 684) levels were measured using a headspace gas chromatography mass spectrometry (HS-GCMS) method with a detection limit of 0.0002% ABV for ethanol. Overall, teas contained mean and median ethanol of 0.77% and 0.62% ABV, respectively, ranging from non-detectable up to 3.62% ABV. Four Kombucha teas (0.6%) made by BC processors tested over 3% ABV, and 31.5% of samples contained ethanol that exceeded the BC regulatory limits for non-alcoholic beverages of 1% ABV. Kombucha manufactured in BC had significantly higher mean ethanol values (1.16% ABV) in comparison to all other places of manufacture. Similarly, mean ethanol tea values obtained from BC processors (1.2% ABV) and restaurants (1.01% ABV) were significantly higher than those obtained at other retail venues. This study demonstrates the potential for alcohol harm to at-risk populations consuming Kombucha teas sold in BC.