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Sodium phosphate monobasic (Monosodium dihydrogen orthophosphate) | Sodium phosphate is a salt of sodium hydroxide and phosphoric acid | Buy buffers online from Sigma Aldrich

Sodium phosphate anhydrous, free-flowing, Redi-Dri, = 99.0 7558-80-7

anhydrous, free-flowing, Redi-Dri<SUP>&#8482;</SUP>, &#8805;99.0%

Sodium phosphate monobasic anhydrous, free-flowing, Redi-Dri&#8482;, &#8805;99.0%

Sodium phosphate monobasic

Synthesis of sorbital based nonionic surfactants and characterization of interfacial and adhesive properties for waterborne pressure-sensitive adhesives

Nanoporous cerium oxide thin film for glucose biosensor

Sodium dihydrogen phosphate as an efficient catalyst for one-pot, three-component synthesis of &#945;-aminophosphonates under solvent-free conditions at room temperature

Synthesis of environment friendly nonionic surfactants from sugar base and characterization of interfacial properties for detergent application

Rapid synthesis of 2-substituted-2, 3-dihydro-4 (1 H)-quinazolinones using boric acid or sodium dihydrogen phosphate under solvent-free conditions

Understanding drug glucuronidation in the dog, a preclinical animal, is important but currently poorly characterized at the level of individual enzymes. We have constructed cDNAs for the 10 dog UDP-glucuronosyltransferases of subfamily 1A (dUGT1As), expressed them in insect cells, and assayed their activity as well as the activity of the nine human UGT1As, toward 14 compounds. The goal was to find out whether individual dUGT1As and individual human UGT1As have similar substrate specificities. The results revealed similarities but also many differences. For example, similarly to the human UGT1A10, dUGT1A11 exhibited high glucuronidation activity toward the 3-OH of 17-β-estradiol, 17-α-estradiol, and ethinylestradiol, and also conjugated the drug entacapone. Unlike the human UGT1A10, however, it failed to catalyze considerable rates of R-propranolol, diclofenac, and indomethacin glucuronidation. The estrogen glucuronidation assays revealed that dUGT1A8 and dUGT1A10 have a capacity to catalyze the formation of (linked) diglucuronides, an activity no human UGT1A exhibited. dUGT1A2-dUGT1A4 are homologs of the human UGT1A4, but none of them catalyzed N-glucuronidation of dexmedetomidine. Contrary to the human UGT1A4, however, dUGT1A2-dUGT1A4 catalyzed indomethacin and diclofenac glucuronidation. It may be concluded that, perhaps with the exception of UGT1A6, high similarities in substrate specificity between individual dog and human UGTs of subfamily 1A are rare or partial. Activity assays with liver and intestine microsomes of both dog and human further revealed interspecies differences, particularly in glucuronidation rates. In the dog, the microsomes assays also strongly suggested important roles for dUGTs of other subfamilies, mainly in the liver.

Dog UDP-glucuronosyltransferase enzymes of subfamily 1A: cloning, expression, and activity.

The aim of this study was the development of poly(D,L-lactide-co-glycolide) (PLGA) microspheres with controlled porosity, to obtain microspheres that afford continuous release of a macromolecular model compound (blue dextran). PLGA microspheres with a size of around 40 μm and narrow size distribution (span value of 0.3) were prepared with a double emulsion membrane emulsification method. Gene expression programming (GEP) analysis was applied to design and formulate a batch of microspheres with controlled porosity that shows continuous release of blue dextran. Low porous microspheres with a high loading efficiency were formed at high polymer concentrations (30% w/w in the oil phase) and were characterized with a burst release <10% and a three-phasic release profile of blue dextran. Increasing porosity (10% w/w polymer concentrations), a sustained release of blue dextran was obtained albeit with up to 40% of burst release. The desired formulation, calculated by GEP, resulted in microspheres with 72% loading efficiency and intermediate porosity. Blue dextran was indeed released continuously in almost a zero order manner over a period of 3 months after an initial small burst release of 9%. By fine-tuning the porosity, the release profile of PLGA microspheres for macromolecules can be predicted and changed from a three-phasic to a continuous release.

Computer modeling assisted design of monodisperse PLGA microspheres with controlled porosity affords zero order release of an encapsulated macromolecule for 3 months.

This study investigated the feasibility of the use of polymeric microparticles for sustained and local delivery of immunomodulatory antibodies in immunotherapy of cancer. Local delivery of potent immunomodulatory antibodies avoids unwanted systemic side effects while retaining their anti-tumor effects. Microparticles based on poly(lactic-co-hydroxymethyl-glycolic acid) (pLHMGA) and loaded with two distinct types of immunomodulatory antibodies (CTLA-4 antibody blocking inhibitory receptors on T cells or CD40 agonistic antibody stimulating dendritic cells) were prepared by double emulsion solvent evaporation technique. The obtained particles had a diameter of 12-15 μm to avoid engulfment by phagocytes and were slightly porous as shown by SEM analysis. The loading efficiency of the antibodies in the microparticles was >85%. The in vitro release profile of antiCD40 and antiCTLA-4 from microparticles showed a burst release of about 20% followed by a sustained release of the content up to 80% of the loading in around 30 days. The therapeutic efficacy of the microparticulate formulations was studied in colon carcinoma tumor model (MC-38). Mice bearing subcutaneous MC-38 tumors were treated with the same dose of immunomodulatory antibodies formulated either in incomplete Freund's adjuvant (IFA) or in microparticles. The antibody-loaded microparticles showed comparable therapeutic efficacy to the IFA formulation with no local adverse effects. The biodegradable microparticles were fully resorbed in vivo and no remnants of inflammatory depots as observed with IFA were present in the cured mice. Moreover the microparticles exhibited lower antibody serum levels in comparison with IFA formulations which lowers the probability of systemic adverse effects. In conclusion, pLHMGA microparticles are excellent delivery systems in providing long-lasting and non-toxic antibody therapy for immunotherapy of cancer.

Polymeric microparticles for sustained and local delivery of antiCD40 and antiCTLA-4 in immunotherapy of cancer.

Beta-lactoglobulin (β-LG), the principal whey protein, possesses multiple sites for binding ligands. Most studies of β-LG-ligand interactions have focused on the formation and dissociation of protein complexes with single ligands, such as α-tocopherol, resveratrol or folic acid. In this study, the possibility of a plurality of bioactive compounds binding simultaneously to β-LG was analysed using protein intrinsic fluorescence quenching. It was found that β-LG could bind two or three ligands simultaneously, although the sequence in which the ligands were added affected binding affinity. The impact of binding to β-LG on physicochemical properties of these three ligands is discussed in view of fluorescence spectroscopy and high performance liquid chromatography results. The data obtained in this study suggest the feasibility of developing β-LG-based carriers of a plurality of active compounds.

A study of multi-ligand beta-lactoglobulin complex formation.

The purification of therapeutic peptides is most often performed using one or more reversed phase chromatography steps. This ensures high purities while keeping the costs of purification under control. In this paper, a doped reversed phase chromatographic material is tested and compared to traditional reversed phase materials. The doping consists of adding limited amounts of ion exchange ligands to the surface of the material to achieve orthogonal separation and increase the non-hydrophobic interactions with the surface. These ionic groups can either be attractive (opposite charge), or repulsive (same charge) to the peptide. The benefit of this new doped reversed phase material is shown through increases in selectivity in diluted conditions and yield and productivity in overloaded (i.e. industrial) conditions. It is the conjectured that all performance characteristics should increase using repulsive doping groups, whereas these characteristics should decrease when using attractive doping groups. This conjecture is shown to be true through several examples, including purifications of industrially relevant peptide crudes, in industrially relevant conditions. Moreover, the effect of ionic strength and organic modifier concentration was explored and shown to be in line with the expected behavior.

Doping reversed-phase media for improved peptide purification.

Layered transition metal dichalcogenides (TMDs) have been the center of attention in the scientific community due to their properties that can be tapped on for applications in electrochemistry and hydrogen evolution reaction (HER) catalysis. We report on the effect of electrochemical treatment of exfoliated MoS2, WS2, MoSe2 and WSe2 nanosheets toward the goal of activating the electrochemical and HER catalytic properties of the TMDs. In particular, electrochemical activation of the heterogeneous electron transfer (HET) abilities of MoS2, MoSe2 and WSe2 is achieved via reductive treatments at identified reductive potentials based on their respective inherent electrochemistry. Comparing all TMDs, the charge transfer activation is most accentuated in MoSe2 and can be concluded that Mo metal and Se chalcogen type are more susceptible to electrochemical activation than W metal and S chalcogen type. With regards to the HER, we show that while MoS2 displayed enhanced performance when subjected to electrochemical reduction, WS2 fared worse upon oxidation. On the other hand, the HER performance of MoSe2 and WSe2 is independent of electrochemical redox treatment. We can conclude therefore that for the HER, S-containing TMDs are more responsive to redox treatment than compounds with the Se chalcogen. Our findings are beneficial toward understanding the electrochemistry of TMDs and the extent to which activation by electrochemical means is effective. In turn, when such knowledge is administered aptly, it will be promising for electrochemical uses.

Catalytic and charge transfer properties of transition metal dichalcogenides arising from electrochemical pretreatment.

Electrospun polyhydroxybutyrate (PHB) fibers were dip-coated by polymethyl methacrylate-co-methacrylic acid, poly(MMA-co-MAA), which was synthesized in different molar ratios of the monomers via free-radical polymerization. Fabricated platfrom was employed for immobilization of the dengue antibody and subsequent detection of dengue enveloped virus in enzyme-linked immunosorbent assay (ELISA). There is a major advantage for combination of electrospun fibers and copolymers. Fiber structre of electrospun PHB provides large specific surface area available for biomolecular interaction. In addition, polymer coated parts of the platform inherited the premanent presence of surface carboxyl (-COOH) groups from MAA segments of the copolymer which can be effectively used for covalent and physical protein immobilization. By tuning the concentration of MAA monomers in polymerization reaction the concentration of surface -COOH groups can be carefully controlled. Therefore two different techniques have been used for immobilization of the dengue antibody aimed for dengue detection: physical attachment of dengue antibodies to the surface and covalent immobilization of antibodies through carbodiimide chemistry. In that perspective, several different characterization techniques were employed to investigate the new polymeric fiber platform such as scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA) measurement and UV-vis titration. Regardless of the immobilization techniques, substantially higher signal intensity was recorded from developed platform in comparison to the conventional ELISA assay.

Polymethacrylate coated electrospun PHB fibers: An exquisite outlook for fabrication of paper-based biosensors.

Ultrasmall polymer nanoparticles are rapidly gaining importance as nanocarriers for drugs and contrast agents. Here, a straightforward modular approach to efficiently loaded and stable sub-20-nm polymer particles is developed. In order to obtain ultrasmall polymer nanoparticles, we investigated the influence of one to two charged groups per polymer chain on the size of particles obtained by nanoprecipitation. Negatively charged carboxylate and sulfonate or positively charged trimethylammonium groups were introduced into the polymers poly(d,l-lactide-co-glycolide) (PLGA), polycaprolactone (PCL), and poly(methyl methacrylate) (PMMA). According to dynamic light scattering, atomic force and electron microscopy, the presence of one to two charged groups per polymer chain can strongly reduce the size of polymer nanoparticles made by nanoprecipitation. The particle size can be further decreased to less than 15 nm by decreasing the concentration of polymer in the solvent used for nanoprecipitation. We then show that even very small nanocarriers of 15 nm size preserve the capacity to encapsulate large amounts of ionic dyes with bulky counterions at efficiencies >90%, which generates polymer nanoparticles 10-fold brighter than quantum dots of the same size. Postmodification of their surface with the PEG containing amphiphiles Tween 80 and pluronic F-127 led to particles that were stable under physiological conditions and in the presence of 10% fetal bovine serum. This modular route could become a general method for the preparation of ultrasmall polymer nanoparticles as nanocarriers of contrast agents and drugs.

Charge-controlled nanoprecipitation as a modular approach to ultrasmall polymer nanocarriers: making bright and stable nanoparticles.

Particulate antigen delivery systems aimed at the induction of antigen-specific T cells form a promising approach in immunotherapy to replace pharmacokinetically unfavorable soluble antigen formulations. In this study, we developed a delivery system using the model protein antigen ovalbumin (OVA) encapsulated in nanoparticles based on the hydrophilic polyester poly(lactide-co-hydroxymethylglycolic acid) (pLHMGA). Spherical nanoparticles with size 300-400 nm were prepared and characterized and showed a strong ability to deliver antigen to dendritic cells for cross-presentation to antigen-specific T cells in vitro. Using near-infrared (NIR) fluorescent dyes covalently linked to both the nanoparticle and the encapsulated OVA antigen, we tracked the fate of this formulation in mice. We observed that the antigen and the nanoparticles are efficiently co-transported from the injection site to the draining lymph nodes, in a more gradual and durable manner than soluble OVA protein. OVA-loaded pLHMGA nanoparticles efficiently induced antigen cross-presentation to OVA-specific CD8+ T cells in the lymph nodes, superior to soluble OVA vaccination. Together, these data show the potential of pLHMGA nanoparticles as attractive antigen delivery vehicles.

Near-infrared labeled, ovalbumin loaded polymeric nanoparticles based on a hydrophilic polyester as model vaccine: In vivo tracking and evaluation of antigen-specific CD8(+) T cell immune response.

In this contribution, the possibility to automatically transfer RPLC methods between different column dimensions and instruments was evaluated using commercial modelling software. The method transfer reliability was tested with loratadine and its 7 related pharmacopeial impurities. In this study, state-of-the-art columns packed with superficially porous particles of 5, 2.6, 1.7 and 1.3μm particles were exclusively employed. A fast baseline separation of loratadine and related impurities (Rs,min=2.49) was achieved under the best analytical conditions (i.e. column of 50mm×2.1mm, 1.3μm, 10-90% ACN in 5min, T=40°C, pH=3, F=0.5ml/min). This optimal method was successfully tested on columns packed with other particle sizes, namely 1.7 and 2.6μm, to reduce pressure drop. The selectivities and retentions remained identical, while the peak widths were logically wider, leading to a reduction of peak capacity from 203 to 181 and 159 on the 1.3, 1.7 and 2.6μm particles, respectively. On the minimum, the resolution was equal to 1.54 on the 50mm×2.1mm, 2.6μm stationary phase. Next to this, the method was transferred to columns of different lengths, inner diameters and particle sizes (100mm×3mm, 2.6μm or 150mm×4.6mm, 5μm). These columns were used on other LC instruments possessing larger dwell volumes. The modelling software employed for developing the original method was able to calculate the new gradient conditions to be used. The accuracy of prediction was excellent, as the average retention time errors between predicted and observed chromatograms were -0.11% and 0.45% when transferring the method to 100mm×3mm and 150mm×4.6mm columns, respectively. This work proves the usefulness and validity of HPLC modelling software for transferring methods between different instruments, column dimensions and/or flow rates.

Reliability of computer-assisted method transfer between several column dimensions packed with 1.3-5μm core-shell particles and between various instruments.

Paclitaxel loaded solid lipid nanoparticles (SLN) of behenic acid were prepared with the coacervation technique. Generally, spherical shaped SLN with mean diameters in the range 300–600 nm were obtained. The introduction of charged molecules, such as stearylamine and glycol chitosan into the formulation allowed to obtain positive SLN with Zeta potential in the 8-20 mV range and encapsulation efficiency in the 25–90% range.Blood–brain barrier (BBB) permeability, tested in vitro through hCMEC/D3 cells monolayer, showed a significantly increase in the permeation of Coumarin-6, used as model drug, when vehicled in SLN. Positive-charged SLN do not seem to enhance permeation although stearylamine-positive SLN resulted the best permeable formulation after 24 h.Cytotoxicity studies on NO3 glioblastoma cell line demonstrated the maintenance of cytotoxic activity of all paclitaxel-loaded SLN that was always unmodified or greater compared with free drug. No difference in cytotoxicity was noted between neutral and charged SLN.Co-culture experiments with hCMEC/D3 and different glioblastoma cells evidenced that, when delivered in SLN, paclitaxel increased its cytotoxicity towards glioblastoma cells.

Positive-charged solid lipid nanoparticles as paclitaxel drug delivery  system in glioblastoma treatment.

Trichloramine is a hazardous disinfection by-product, which is present in chlorinated swimming pools. Although it is primarily taken up by inhalation, the concentration in pool water is important to monitor pool water quality and to assess trichloramine mitigation strategies. To date, scarce data is available on trichloramine concentration in pool water due to the lack of a suitable and easily applicable analytical method. This study presents a novel low cost, colorimetric method which is easy to operate and suitable for on-site measurements of trichloramine concentrations ≥0.05 μM (≥0.01 mg L(-1) as Cl2). The analytical method (termed "extraction-based ABTS method") consists of, (i) trichloramine stripping from pool water samples, (ii) passing it through a solid phase filter, composed of silica gel impregnated with sulfamic acid to eliminate interferences and (iii) trichloramine reaction with the indicator 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) to produce the coloured ABTS(•-) radical, which is measured at λ = 405 nm to determine the trichloramine concentration in the pool water sample. A comparison of the extraction-based ABTS method with membrane introduction mass spectrometry (MIMS) for 28 pool samples revealed a good correlation of the two methods. The trichloramine concentration in pool samples is correlated to HOCl, which is the most important factor for its formation. Other parameters such as combined chlorine and pH play a minor role while no correlation between trichloramine and the urea or the TOC concentration was observed. On-site measurements with MIMS in a wading pool over 6 days with a time resolution of 1 h confirmed that trichloramine concentrations strongly responded to changes in free chlorine concentrations. A diurnal measurement of trichloramine with a time resolution of 20 min revealed that trichloramine concentrations reacted quickly and sensitively to the bather load and that urea is probably not the main precursor for its formation.

Comparison of a novel extraction-based colorimetric (ABTS) method with membrane introduction mass spectrometry (MIMS): trichloramine dynamics in pool water.

Bioactive sphingolipids including ceramides are involved in a variety of pathophysiological processes by regulating cell death and survival. The objective of the current study was to examine ceramide metabolism in preeclampsia, a serious disorder of pregnancy characterized by oxidative stress, and increased trophoblast cell death and autophagy. Maternal circulating and placental ceramide levels quantified by tandem mass spectrometry were elevated in pregnancies complicated by preeclampsia. Placental ceramides were elevated due to greater de novo synthesis via high serine palmitoyltransferase activity and reduced lysosomal breakdown via diminished ASAH1 expression caused by TGFB3-induced E2F4 transcriptional repression. SMPD1 activity was reduced; hence, sphingomyelin degradation by SMPD1 did not contribute to elevated ceramide levels in preeclampsia. Oxidative stress triggered similar changes in ceramide levels and acid hydrolase expression in villous explants and trophoblast cells. MALDI-imaging mass spectrometry localized the ceramide increases to the trophophoblast layers and syncytial knots of placentae from pregnancies complicated by preeclampsia. ASAH1 inhibition or ceramide treatment induced autophagy in human trophoblast cells via a shift of the BOK-MCL1 rheostat toward prodeath BOK. Pharmacological inhibition of ASAH1 activity in pregnant mice resulted in increased placental ceramide content, abnormal placentation, reduced fetal growth, and increased autophagy via a similar shift in the BOK-MCL1 system. Our results reveal that oxidative stress-induced reduction of lysosomal hydrolase activities in combination with elevated de novo synthesis leads to ceramide overload, resulting in increased trophoblast cell autophagy, and typifies preeclampsia as a sphingolipid storage disorder.

Disruption of sphingolipid metabolism augments ceramide-induced autophagy in preeclampsia.

Nanostructured transition-metal phosphides have recently emerged as Earth-abundant alternatives to platinum for catalyzing the hydrogen-evolution reaction (HER), which is central to several clean energy technologies because it produces molecular hydrogen through the electrochemical reduction of water. Iron-based catalysts are very attractive targets because iron is the most abundant and least expensive transition metal. We report herein that iron phosphide (FeP), synthesized as nanoparticles having a uniform, hollow morphology, exhibits among the highest HER activities reported to date in both acidic and neutral-pH aqueous solutions. As an electrocatalyst operating at a current density of -10 mA cm(-2), FeP nanoparticles deposited at a mass loading of ∼1 mg cm(-2) on Ti substrates exhibited overpotentials of -50 mV in 0.50 M H2SO4 and -102 mV in 1.0 M phosphate buffered saline. The FeP nanoparticles supported sustained hydrogen production with essentially quantitative faradaic yields for extended time periods under galvanostatic control. Under UV illumination in both acidic and neutral-pH solutions, FeP nanoparticles deposited on TiO2 produced H2 at rates and amounts that begin to approach those of Pt/TiO2. FeP therefore is a highly Earth-abundant material for efficiently facilitating the HER both electrocatalytically and photocatalytically.

Electrocatalytic and photocatalytic hydrogen production from acidic and neutral-pH aqueous solutions using iron phosphide nanoparticles.

Malignant melanoma is the most dangerous type of skin cancer. Although recent progress in treatment has been achieved, lack of response, drug resistance and relapse remain major problems. The tumor suppressor p53 is rarely mutated in melanoma, yet it is inactive in the majority of cases due to dysregulation of upstream pathways. Thus, we screened for compounds that can activate p53 in melanoma cells. Here we describe effects of the small molecule MJ25 (2-{[2-(1,3-benzothiazol-2-ylsulfonyl)ethyl]thio}-1,3-benzoxazole), which increased the level of p53-dependent transactivation both as a single agent and in combination with nutlin-3. Furthermore, MJ25 showed potent cytotoxicity towards melanoma cell lines, whilst having weaker effects against human normal cells. MJ25 was also identified in an independent screen as an inhibitor of thioredoxin reductase 1 (TrxR1), an important selenoenzyme in the control of oxidative stress and redox regulation. The well-characterized TrxR inhibitor auranofin, which is FDA-approved and currently in clinical trials against leukemia and a number of solid cancers, displayed effects comparable with MJ25 on cells and led to eradication of cultured melanoma cells at low micromolar concentrations. In conclusion, auranofin, MJ25 or other inhibitors of TrxR1 should be evaluated as candidate compounds or leads for targeted therapy of malignant melanoma.

Redox effects and cytotoxic profiles of MJ25 and auranofin towards malignant melanoma cells.

Redi-Dri™ prevents hygroscopic powders, such as inorganic salts, from absorbing moisture and forming clumps, leaving the salts free-flowing every time.

Sodium phosphate monobasic

anhydrous, free-flowing, Redi-Dri^™, ≥99.0%

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