Commercial Gel Research Articles

Modified acid-PAGE method for rapid screening and phenotyping of wheat gliadin mutant lines

Acid-polyacrylamide gel electrophoresis (A-PAGE) is used to phenotype different varieties of wheat based on their gliadin profiles. The family of gliadin proteins is a major component of wheat gluten. Gluten is the major determinant of the unique viscoelastic property of wheat dough that is necessary in the production of important food products including bread, cake, cookies and pasta. However, several gliadin proteins are also known to be causal agents in triggering human immunogenic responses that lead to several gluten-related health risks like celiac disease and wheat-dependent exercise-induced anaphylaxis. Therefore, research to identify wheat lines with reduced levels of immunogenic proteins is being vigorously pursued in several laboratories around the world. Unfortunately, no commercial A-PAGE gels are currently available for cereal researchers to use for separating wheat gliadins. This work reports the development of an easy-to-use A-PAGE protocol to resolve gliadins with high reproducibility and resolution to screen and phenotype gliadin deficient lines in wheat.•This acetic acid based A-PAGE method with urea utilizes commercially available reagents and materials to make gel casting simpler and more efficient.•It can be used to phenotype different wheat varieties to establish purity and to identify mutants of wheat with altered gliadin protein profiles.

<p>Crystalline and Amorphous Preparation of Aluminum Hydroxide Nanoparticles Enhances Protective Antigen Domain 4 Specific Immunogenicity and Provides Protection Against Anthrax</p>

IntroductionAluminum salts, although they have been used as adjuvants in many vaccine formulations since 1926, exclusively induce a Th2-biased immune response, thereby limiting their use against intracellular pathogens like Mycobacterium tuberculosis.Methods and ResultsHerein, we synthesized amorphous and crystalline forms of aluminum hydroxide nanoparticles (AH nps) of 150–200 nm size range. Using Bacillus anthracis protective antigen domain 4 (D4) as a model antigen, we demonstrated that both amorphous and crystalline forms of AH nps displayed enhanced antigen D4 uptake by THP1 cells as compared to commercial adjuvant aluminum hydroxide gel (AH gel). In a mouse model, both amorphous and crystalline AH nps triggered an enhanced D4-specific Th2- and Th1-type immune response and conferred superior protection against anthrax spore challenge as compared to AH gel. Physicochemical characterization of crystalline and amorphous AH nps revealed stronger antigen D4 binding and release than AH gel.ConclusionThese results demonstrate that size and crystallinity of AH nps play important roles in mediating enhanced antigen presenting cells (APCs) activation and potentiating a strong antigen-specific immune response, and are critical parameters for the rational design of alum-based Th1-type adjuvant to induce a more balanced antigen-specific immune response.

Uptake of insecticides and fungicides by impregnable and refractory coniferous wood species treated with commercial bio-based emulsion gel formulations

Even in dry state, wood can be prone to biological degradation. Preservation is a prerequisite to confer pro-tection and durability to wood. This is conventionally achieved by impregnating the wood with pesticides.A key point in these treatments is the complex process of wood penetrability. We focused on the relation between the penetration of wood preservatives, wood microstructure, and the physical characteristics of formulations in the impregnation of the easily impregnable pine (Pinus sylvestris), and the refractory spruce (Picea abies). In this work, specimens from the two species were impregnated with three types of commercial bio-based emul-sion gels formulations containing insecticides and fungicides. The effect of treatment method using dipping, surface spraying, and vacuum-impregnation, on the retention of the active agents was analyzed. Visual assess-ment, and qualitative and quantitative analyses of cypermethrin, permethrin and propiconazole by gas liquid chromatography coupled to mass spectroscopy showed enhanced penetration of the active agents, and revealed differences of penetration performance of each agent. The suitable combinations of solvents and surfactants used in the bio-based formulations enabled rapid wood penetration and high yields retention. The capacity of penetration and retention of our gel formulations is discussed in terms of the connectivity of the conducting cells network of the two wood species

In-vitro release study of Diclofenac sodium from topical gel formulations using diffusion cell

The present research study was to explore the in-vitro drug release and kinetics of different brands of diclofenac sodium gel formulations (Brand A, B, C) available in the local pharmaceutical market of Tamilnadu with a lab made reference gel by using vertical diffusion cell through synthetic membrane. For this study, three widely prescribed brands of topical gel formulations (Brand A, B, C) were chosen. All of these brands were containing 1% of diclofenac sodium as active drug. The drug release study was carried out using vertical diffusion cell apparatus and the analysis was performed with UV spectroscopy. To find out the release kinetics, it was interpreted with various mathematical models like zero order, first order, Higuchi model and Korsmeyer-peppas model. The R2 value for each kinetic model was also determined which indicated the linearity of release kinetics for each brand. It was found that all the brands tend to follow zero order kinetics that fits into Higuchi model. From the results obtained, Brand B of commercial gel formulation was found to be similar to that of the reference gel formulation. Difference in vehicle components was found to contribute to the difference in drug release of the other brands. And the study assumes that the available brands of Diclofenac sodium gel topical formulations in Tamilnadu generally follow zero order release kinetics that fits into Higuchi model.

A Novel Application of EIS for Quantitative Coating Quality Assessment During Neutral Salt Spray Testing of High-Durability Coatings

The aim of the study was to exemplify the benefits of using electrochemical impedance spectroscopy (EIS) for quantification of coating quality during accelerated corrosion testing before the appearance of visual changes on the surface of the coating. The study included an innovative application of the commercial flexible gel electrodes in a two-electrode setup for following the impedance of the two high-durability offshore coating systems exposed to 1440 h of neutral salt spray (NSS) according to EN ISO 9227. The results were compared to those of the EIS measurements during 8000 h long exposure to a liquid electrolyte in a press-on cell according to the established EN ISO 16773 method. Complementary methods of differential scanning calorimetry, Fourier transform infrared spectroscopy and thermogravimetric analysis have been used for surface, interface and depth profiling of coating characteristics that were commented with respect to the EIS results. The technique was applied on high-durability coatings Zn (R) + EP + EP or PUR intended for the protection in the coastal and offshore areas corresponding to C5- (H) and CX corrosivity categories in accordance with EN ISO 12944. EIS has been found to give sound quantitative results for coating impedance and a good estimation of long term coating behaviour within the first 100 h of accelerated exposure. It can be considered a promising tool for the early detection of coating damage during weathering tests.

Electrostatic Deposition of the Oxidized Kraft Lignin onto the Surface of Aminosilicas: Thermal and Structural Characteristics of Hybrid Materials.

In recent years, functional polymeric compounds have been widely used to modify the silica surface, which allows one to obtain the corresponding organomineral composites for broad application prospects. In this case, lignin—a cross-linked polyphenolic macromolecule—is of great interest according to its valuable properties and possible surplus as a by-product of pulp and paper industry and various biorefinery processes. Hybrid materials based on kraft softwood lignin and silica were obtained via the electrostatic attraction of oxidized lignin to the aminosilica surface with different porosities, which were prepared by the amination of the commercial silica gel with an average pore diameter of 6 nm, and the silica prepared in the lab with the oxidized kraft lignin and lignin–silica samples with an average pore diameter of 38 nm was investigated by physicochemical methods: two-dimensional nuclear magnetic resonance (NMR), 31P NMR, Fourier transform infrared spectroscopy, thermogravimetric analysis in nitrogen and air atmosphere, scanning electron microscopy, and adsorption methods. After oxidation, the content of carboxylic groups almost doubled in the oxidized lignin, compared to that in the native one (0.74 mmol/g against 0.44 mmol/g, respectively). The lignin content was deposited onto the surface of aminosilica, depending on the porosity of the silica material and on the content of amino groups on its surface, giving lignin–aminosilica with 20% higher lignin content than the lignin–aminosilica gel. Both types of lignin–silica composites demonstrate a high sorptive capacity toward crystal violet dye. The suggested approach is an easy and low-cost way of synthesis of lignin–silica composites with unique properties. Such composites have a great potential for use as adsorbents in wastewater treatment processes.

A comparative analysis of cultivation techniques of epithelial stem cells of cornea and creation of biomedical cell product (biocomposite) on the basis biocompatible matrix and stem cells

In recent years the autologous stem cells of front cornea epithelium (CSC) are increasingly used in the treatment of degenerative diseases of this transparent part of the outer shell of the eye. Limb is considered as a specialized storage for these cells in eye. A number of techniques for isolation of stem cells from limb epithelium and their cultivation in vitro were developed. Goal of the work: To analyze the possibilities of two methods of cultivation of epithelial stem cells front epithelium of cornea (CSC), explants and suspension ones by criteria of efficiency of proliferation, time consumption and constancy of morphology and function parameters of cell cultures. To study of biocompatibility of CSC with commercial gel preparations for its application as an ingredient of biocomposite to use in clinical practice. The primary multilayer CSC cultures were obtained by two methods (explant and suspension) from biopsies of intact parts of cornea limb of 10 patients at the age from 39 to 73 years suffering different types of ceratopathies. Under comparative analysis of CSC cultures their viability, proliferation potential and immunophenotype were investigated. It was shown that explant method is more effective as compared with suspension one as it allows to gain the significant amount of cells with epithelium like morphology. The cell population was presented primarily by epithelium CSC: 95% of cells synthesized K19+ protein. CSC proliferation index of cells isolated by explant method was by 3.5-4 times higher, the time of doubling of population at cultivation in DMEM/F12 medium with 10 ng/ml of EGF was 48 h. Using explant method from one limb biopsy (1 х2 mm) a biomass of CSC in amount of 4 ± 1,2 mln during 3-4 weeks (1-2 passages) was obtained. It was show under investigation for biocompatibility of cells with a number of commercial gel preparations that preparation Provisk is the best on this indicator and this allows to recommend it as a carrier for cells when biomedical cell product are produced.

Determination of plasma bone-specific alkaline phosphatase isoenzyme activity in Holstein calves using a commercial agarose gel electrophoresis kit.

We measured the bone-specific alkaline phosphatase (ALP) isoenzyme activity in 67 plasma samples from 14 newborn Holstein calves using both a conventional method (featuring heat inactivation) and a commercial agarose gel electrophoresis (AGE) kit; the relevant isoenzymes were termed bone-specific ALP (BAP) and ALP isoenzyme 3 (ALP3). We explored whether the AGE kit afforded reliable data when used to analyze samples from Holstein calves. The blood was collected from the jugular vein of each calf immediately prior to the first colostrum feeding (pre-feeding), 20 and 40 h after pre-feeding, and on days 4 and 7; whereas three samples (from three calves) were not obtained. The total plasma ALP activity varied widely, exceeding the ranges of reference values. On electrophoresis, 52 of 67 plasma samples (77.6 %) clearly contained both ALP isoenzyme 2 and ALP3, as did control human serum. The total ALP activity of the 52 samples ranged from 166-1989 U/L (median: 1013 U/L), whereas the values for the other 15 samples (22.4%) exhibiting abnormal isoenzyme fractionation ranged from 1014-5118 U/L (median: 1780 U/L). In the 52 plasma samples exhibiting clearly separated isoenzymes, ALP3 and BAP activities were strongly positively correlated as revealed by Deming regression (y = 0.93x + 22.6, p⟨0.0001) and Bland-Altman analysis (ALP3/BAP activities limit of agreement: -5.1%). Thus, the AGE kit yields useful information on newborn calves, and can replace the conventional method when the total plasma ALP activity is less than approximately 1000 U/L.

Efficacy of autologous platelet rich plasma versus regular dressing in chronic wounds

Background: Chronic wounds are a frequent problem and pose a heavy burden to the service provider. Platelet extract containing several growth factors used on chronic wounds has shown impressive results in both healing percentage and time for epithelisation. Platelet extract from the patient’s own blood has been used in trials as a cheap and equally effective alternative to commercial platelet gels. The aim of the study was to demonstrate the therapeutic role of autologous platelet rich plasma (APRP) in epithelialisation and reduction in size of chronic wounds of lower limb.Methods: It is a case control study, conducted at Sri Adichunchanagiri Hospital and Research Centre, B.G. Nagara, Karnataka. Conducted during January 2017 to June 2018 this study consisted of 30 patients with chronic ulcers between the age group of 18-80 years, with duration of ulcer ranging from 12 to 26 weeks. After obtaining consent they were randomly allotted into control and test groups with 15 patients each. Control group patients were treated with conventional dressing and in test group APRP dressing was done. Later percentage decrease in wound size was assessed.Results: Ulcer size decreased significantly (p<0.0001) in test group compared to control group. No unwanted effects or complications noted.Conclusions: APRP is a safe and effective treatment modality for chronic non-healing ulcers. It enhances healing and also decreases the associated cost and morbidity. Further research and randomized controlled clinical trials on larger patient population are necessary to validate the results.

Preparation, Characterisation, and Topical Delivery of Terbinafine.

Terbinafine (TBF) is commonly used in the management of fungal infections of the skin because of its broad spectrum of activity. Currently, formulations containing the free base and salt form are available. However, there is only limited information in the literature about the physicochemical properties of this drug and its uptake by the skin. In this work, we conducted a comprehensive characterisation of TBF, and we also examined its percutaneous absorption in vitro in porcine skin. TBF-free base was synthesised from the hydrochloride salt by a simple proton displacement reaction. Both the free base and salt form were further analysed using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Delivery of TBF-free base in excised porcine skin was investigated from the following solvents: Isopropyl myristate (IPM), propylene glycol monolaurate (PGML), Transcutol® (TC), propylene glycol (PG), polyethylene glycol 200 (PEG 200), oleic acid (OL), ethanol (EtOH), and isopropyl alcohol (IPA). Permeation and mass balance studies confirmed that PG and TC were the most efficacious vehicles, delivering higher amounts of TBF-free base to the skin compared with a commercial gel (p < 0.05). These preliminary results are promising and will inform the development of more complex formulations in future work.

Potato ingestion is as effective as carbohydrate gels to support prolonged cycling performance.

Carbohydrate (CHO) ingestion is an established strategy to improve endurance performance. Race fuels should not only sustain performance but also be readily digested and absorbed. Potatoes are a whole-food-based option that fulfills these criteria, yet their impact on performance remains unexamined. We investigated the effects of potato purée ingestion during prolonged cycling on subsequent performance vs. commercial CHO gel or a water-only condition. Twelve cyclists (70.7 ± 7.7 kg, 173 ± 8 cm, 31 ± 9 yr, 22 ± 5.1% body fat; means ± SD) with average peak oxygen consumption (V̇o2peak) of 60.7 ± 9.0 mL·kg−1·min−1 performed a 2-h cycling challenge (60–85% V̇o2peak) followed by a time trial (TT; 6 kJ/kg body mass) while consuming potato, gel, or water in a randomized-crossover design. The race fuels were administered with [U-13C6]glucose for an indirect estimate of gastric emptying rate. Blood samples were collected throughout the trials. Blood glucose concentrations were higher (P < 0.001) in potato and gel conditions compared with water condition. Blood lactate concentrations were higher (P = 0.001) after the TT completion in both CHO conditions compared with water condition. TT performance was improved (P = 0.032) in both potato (33.0 ± 4.5 min) and gel (33.0 ± 4.2 min) conditions compared with water condition (39.5 ± 7.9 min). Moreover, no difference was observed in TT performance between CHO conditions (P = 1.00). In conclusion, potato and gel ingestion equally sustained blood glucose concentrations and TT performance. Our results support the effective use of potatoes to support race performance for trained cyclists.NEW & NOTEWORTHY The ingestion of concentrated carbohydrate gels during prolonged exercise has been shown to promote carbohydrate availability and improve exercise performance. Our study aim was to expand and diversify race fueling menus for athletes by providing an evidence-based whole-food alternative to the routine ingestion of gels during training and competition. Our work shows that russet potato ingestion during prolonged cycling is as effective as carbohydrate gels to support exercise performance in trained athletes.

Culture Cell Block Controls as a Tool to the Biomolecular Diagnosis of Infectious Diseases.

The cell block (CB) technique has allowed easy obtainment of samples such as cellular and culture suspensions, to perform specific molecular tests such as immunohistochemistry and in situ hybridization. It has been improved along time, accuracy, and quality of the diagnoses, however, the cost of a commercial gel matrix for the preparation of CB is high and not suitable depending on the situation. The objective of this study is to test agarose as an alternative to the commercial gel matrix in the preparation of Aspergillus fumigatus' CB.

Computer simulation of commercial conductive gels and their application to increase the safety of electrochemotherapy treatment

Electrochemotherapy (ECT) exploits the phenomenon of electroporation, which is the increase of cell permeability through the application of an electrical field. This technique is applied in medical centers in Europe and in veterinary clinics in Europe, Brazil, and Argentina. ECT treatment requires a minimum electric field and anti-cancer drugs (e.g., bleomycin). Irregularly shaped tumors may induce ECT treatment failure because of irregular electric field distribution. Conductive gels have been suggested as a means to increase the homogeneity of the electrical field distribution. The aim of this work was to evaluate if commercial conductive gels could increase the safety of ECT. A veterinary case study of ECT in a dog provided the tumor dimensions for the numerical model. Electrode displacement and commercial conductive gels were simulated to determine if they improved ECT treatments. We conclude that a commercial gel having a conductivity of 0.2 S/m when used in combination with effective treatment planning may improve the outcome of electrochemotherapy procedures.

Progesterone loaded thermosensitive hydrogel for vaginal application: Formulation and in vitro comparison with commercial product

Progesterone (PGT) is a natural hormone that stimulates and regulates various important functions, such as the preparation of the female body for conception and pregnancy. Due to its low water solubility, it is administered in a micronized form and/or in vehicles with specific solvents requirements. In order to improve the drug solubility, inclusion complexes of PGT and β-cyclodextrins were obtained by the freeze-drying method. Two β-cyclodextrins (native and methylated) in two solvents (water and water:ethanol) and different molar ratio of the reagents were the variables tested for the selection of the best condition for the preparation of the complexes. The PGT/randomly methylated-β-cyclodextrin complexes were incorporated into chitosan thermosensitive hydrogels, as an alternative formulation for the vaginal administration of PGT. Neither the micro and macroscopic characteristics of the gels nor the transition time from solution to gel were modified after the complexes incorporation. In addition, chitosan gels with complexes resisted better the degradation in simulated vaginal fluid in comparison to commercial gel (Crinone®). The chitosan gel with inclusion complexes and Crinone® were tested in vitro in a diffusion assay to evaluate the delivery of the hormone and its diffusion through porcine epithelial mucosa obtained from vaginal tissue. Chitosan gel presented sustained diffusion similar to the exhibited by commercial gel. The use of chitosan gels with inclusion complexes based on cyclodextrins would be a viable alternative for vaginal administration of PGT.

Quantitative inkjet application on self-printed, binder-free HPTLC layers for submicromole-scaled analytical 1H NMR spectroscopy

High-performance thin-layer chromatography (HPTLC) combined with 1H nuclear magnetic resonance (NMR) spectroscopy has only been demonstrated over a small spectral range so far. The self-printing of chromatographic plates with a modified 3D slurry printer allowed the operator to influence the composition of the adsorbent slurry and thus the purity of the adsorbent layer. The combination of such self-printed, binder-free HPTLC plates with inkjet-driven sample application made possible submicromole-scaled analytical 1H NMR spectroscopy. This was proven using pure HPTLC adsorbents. For comparison, commercial silica gel HPTLC plates were purified by pre-development with solvents for spectroscopy, whereas commercial silica gel HPTLC particles were self-printed on the glass plate after purification under solvent pressure in a recycled HPLC cartridge. Evaluating the signals from different treatments, seven background signals disappeared in the proton spectra and three were reduced to a minimum by use of pre-developed commercial HPTLC plates. In the case of the self-printed, binder-free HPTLC plates made of purified adsorbent, most of the spectral background signals were reduced to a minimum, thus these spectra showed the highest cleanness and most pure analyte proton spectra. For the first time, the full 1H NMR spectroscopy range was made available after an HPTLC separation. This proof of principle opens the avenue for submicromole-scaled analytical 1H NMR spectroscopy.

Linking the multiscale porous structure of hexacyanoferrate-loaded silica monoliths to their hydrodynamic and cesium sorption properties

Multiscale porous silica monoliths functionalized with potassium/copper hexacyanoferrate (HCF) have been evaluated for the column extraction of cesium from natural water. Compared with commercial silica gel particles, results show that the hierarchically porous architecture of the monoliths improves the bed efficiency in column extraction, and the selectivity, distribution coefficient and exchange kinetics in batch extraction. Cesium breakthrough experiments show that these preferable properties of the monolithic structure are maintained in column operation. This analysis of the batch and breakthrough experiments is supported by scanning and transmission electron microscopy data, residence time distributions, and reactive transport modeling assuming dispersive flow in the macroporous intraskeletal channels and diffusion inside the walls of the structure and the HCF aggregates.

A pectin-gelatin gel containing oral rehydration solution and the release of sodium chloride under simulated gastric conditions

Both gelatin and pectin have the ability to trap salt and facilitate its release under simulated gastric conditions. The objective of this study was to develop a pectin-gelatin gel fortified with oral rehydration solution/s (ORS) that can maintain a more rigid structure to limit salt mobility (potentially less salty taste), yet allow rapid release in simulated gastric conditions. Two gels containing both pectin and gelatin were developed: (1) low salt (LS) containing 2.6 g/L salt and 13.5 g/L sugar and (2) high salt (HS) containing 5.2 g/L salt and 27.0 g/L sugar. The ORS-fortified gels were compared with commercially available gelatin gels and a control pectin-gelatin gel without added salt or sugar. A stronger gel network (higher G′) and higher viscosity was noted for HS compared to other samples. HS had slower salt release (80.70 ± 1.92%) than LS (95.95 ± 3.82%) at 1 min in simulated gastric conditions. After 120 min, HS showed up to 99.38 ± 1.08% release of salt, while LS had 95.95 ± 3.82% release. HS had a favorable textural profile, having values more similar to the ready-to-eat commercial cup gel than did the LS formulation. The HS formulation resulted in a stable structure for ORS delivery and beneficial release properties.

Gastrointestinal Symptoms Related to Potato Ingestion During Cycling in Trained Athletes (P23-012-19)

ObjectivesCarbohydrate (CHO) ingestion is an established nutritional strategy to improve endurance performance, yet currently available products may contribute to gastrointestinal (GI) distress. Potatoes have a high-glycemic index, indicating that their CHO content is readily available. We aimed to compare the effects of ingesting potato purée (POT), commercial CHO gel (GEL), or a control (water, CTL) during cycling on GI Symptoms and affective indices in trained athletes. MethodsIn a randomized crossover study, twelve trained cyclists (9 M and 3F; 30.5 ± 8.7y; 70.6 ± 7.6 kg; 1.70 ± 7 cm; 60.7 ± 8.9 mL/kg/min) completed a 2 h cycling challenge (60–85%VO2max) followed by a 6 kJ/kg time trial. Cyclists were randomly assigned to consume POT, GEL, or CTL during the challenge. Rating of perceived exertion (RPE), GI symptoms, and affective responses (Feeling Scale −5/+5) were collected throughout the challenge via visual analog scales. Differences between treatments were assessed by mixed model analysis of variance using time and condition as a fixed factor and subject as a random factor. All data represent mean ± standard deviation. ResultsRPE was not different between POT, GEL, or CTL condition at the end of the cycling challenge (POT: 17 ± 1; GEL: 17 ± 1, CTL: 18 ± 1, P > 0.05). Higher GI symptoms (P < 0.01) were observed at the end of the challenge during POT condition (15 ± 3%) when compared to GEL (8 ± 3%) and CTL (7 ± 3%), with no significant difference in these symptoms prior to this time. FS response significantly increased (P = 0.04) during POT trial (2 ± 2) compared to GEL (0 ± 0.2) and CTL (0 ± 2) conditions at end of the challenge. ConclusionsWhile POT ingestion resulted in greater GI distressed compared to CHO gel, cyclists perceived the exertion to be similar and even reported feeling more pleasant after POT ingestion in endurance exercise. Funding SourcesAlliance for Potato Research and Education.

Sustainable Production of Cellulose-Based Hydrogels with Superb Absorbing Potential in Physiological Saline.

Nowadays, most of the commonly used superabsorbent polymers (SAPs) are derived from synthetic polymers, particularly acrylic acid and its copolymers made with acrylamide. Here, we describe a novel and environmentally friendly aqueous-based process for fabrication of a new, natural, cellulose-based SAP (hydrogel). In this two-step process, cellulose was first reacted with sodium monochloroacetate (MCA) to obtain carboxymethyl cellulose (CMC) and then cross-linked with epichlorohydrin (ECH). In distilled water (d-water), the water retention value (WRV) of the newly fabricated hydrogels reached 725 g d-water/g gel, which is significantly greater than any other commercially available superabsorbent cellulose-based material (WRV of 10–100 g/g) and comparable to the commercial synthetic (polyacrylate) SAP gels (WRV of up to 1000 g/g). In saline water (s-water; 0.9% NaCl), the maximum WRV attained was 118 g s-water/g gel, which exceeds more than 2-fold the WRV of commercial gels (40–50 g/g). Compositional analysis was carried out to determine the amount of carboxyl groups and average molecular mass, and the parameters for hydrogel preparation were optimized. The natural SAP was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The hydrogels showed good re-swelling properties losing only 5–10% of their capabilities to reabsorb d-water when reused in four consecutive cycles. Because of their superior swelling properties in physiological saline, the new hydrogels can compete with their synthetic counterparts in applications such as high-value hygiene and biomedical products.

Comparison of diffusion, cytotoxicity and tissue inflammatory reactions of four commercial bleaching products against human dental pulp stem cells

Multiple side effects related to bleaching were found to occur in the dental pulp tissue, including decreased cell metabolism and viability. In this work we evaluated the in vitro diffusion capacity, cytotoxicity and biocompatibility of four commercial bleaching products on stem cells from human dental pulp (hDPSCs). Two commercial bleaching gels hydrogen peroxide-based (HP), Norblanc Office 37.5% (Nor-HP) and Opalescence Boost 40% (Opal-HP) were applied for 30 min to enamel/dentine discs. Another two gels from the same manufacturers, 16% carbamide peroxide-based (CP), Norblanc Home (Nor-CP) and Opalescence CP 16% (Opal-CP), were applied for 90 min. The diffusion of HP was analysed by fluorometry. Cytotoxicity was determined using the MTT assays, the determination of apoptosis, immunofluorescence assays and intracellular reactive oxygen species (ROS) level. Tissue inflammatory reactions were evaluated histopathologically in rats. Statistical differences were performed by one-way ANOVA and Bonferroni post-test (α < 0.05). Normon products showed lower cytotoxicity and diffusion capacity than the Ultradent products. A high intracellular ROS level was measured in hDPSCs after exposure to Opal-HP. Finally, a severe necrosis of both coronal and radicular pulp was observed with Opal-HP. Similar concentrations of hydrogen peroxide and carbamide peroxide in a variety of bleaching products exhibited different responses in cells and dental pulp tissue, suggesting that bleaching products contain unknown agents that could influence their toxicity.