Aim: To investigate the preparation, in vitro release, in vivo pharmacokinetics and tissue distribution of a novel polymeric micellar formulation of paclitaxel (PTX) with Pluronic P123. Methods: The polymeric micelles of paclitaxel with Pluronic P123 were prepared by a solid dispersion method. The characteristics of micelles including particle size distribution, morphology and in vitro release of PTX from micelles were carried out. PTX-loaded micellar solutions were administered through the tail vein to healthy Sprague-Dawley rats and Kunming strain mice to assess the pharmacokinetics and tissue distribution of PTX, respectively. Taxol, the commercially available intravenous formulation of PTX, was also administered as control. Results: By using a dynamic light scattering sizer and a transmission electron microscopy, it was shown that the PTX-loaded micelles had a mean size of approximately 25 nm with narrow size distribution and a spherical shape. PTX was continuously released from Pluronic ...
The non-commercial copolymers E45S8, E45S17 and their mixtures with Pluronic® P123 (E21P67E21) were studied as carriers of the model drug griseofulvin. Critical micelle concentration (cmc) (dye solubilisation method), drug solubilisation capacity (Scp and Sh) determined by ultraviolet-visible (UV-Vis) spectroscopy and 1H nuclear magnetic resonance (1H NMR) and cytotoxicity (LDH activity in human neutrophils) were studied. E45S17 1.0 wt.% dispersions presented colloidal aggregates limiting its Scp in comparison to E45S8, but in 0.1 wt.% solutions this phenomenon seemed to be absent and E45S17 presented a higher Scp. The mixtures that showed the best Scp results contained 50% of P123 and presented low cmc. An evaluation of literature data suggested a minimum Em content of 62% in EmSn copolymers below which the increase of Sn length does not lead to an increase of Sh. The results suggested no toxicity of the copolymers on human neutrophils, supporting the use of P123 and poly(styrene oxide) ...
Drug delivery to the brain presents many challenges to the pharmaceutical scientist in part due to limited drug transport across the blood brain barrier (BBB). This dissertation focused on evaluation of a novel protein, Zonula occludens toxin (Zot) and a P-glycoprotien (P-gp) modulator, itraconazole, to enhance brain drug delivery, and to investigate their potential for drug interactions in the kidney. Zot, a protein elaborated by vibrio cholerae, is known to modulate tight junctions in intestinal epithelial cell models and enhance oral bioavailability. We initially evaluated the ability of Zot to modulate tight junctions in a bovine brain microvessel endothelial cell (BBMEC) model. The results from this study indicate that Zot transiently and reversibly enhances paracellular transport of selected marker and chemotherapeutic compounds. Subsequent in vivo studies in rats were consistent with these findings, where Zot caused a four-fold enhancement in brain uptake of paclitaxel, a poorly permeable ...
Colloidal assemblies of surfactants and polymers in aqueous solutions have been used by human mankind for hundreds of years and they are of great importance in many of our technological processes, such as fabrication of soap and papermaking. Less than two decades ago the idea of using colloidal assemblies as templates of inorganic materials was borne. A new population of materials, referred to as surfactant templated materials, took form. These materials showed extraordinary properties such as monodisperse pore size distribution, large surface areas and pore volumes.. The main focus of this thesis has been on synthesis and functionalisation of spherical mesostructured silica particulate materials. In the first part of the work, mesostructured materials with expanded pores have been produced using a well established aerosol-based method as well as the newly developed emulsion and solvent evaporation (ESE) method. Increase in pore size was realized through using Pluronic block copolymer F127 ...
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Double hydrophilic block copolymers (DHBC) self-assemble to various structures in aqueous solutions due to a strong difference in hydrophilicity. This is in contrast to amphiphilic block copolymers that self-assemble due to the insolubility of the hydrophobic block in water. In their recent contribution, Schmidt and co-workers were able to extend the principle of double hydrophilic self-assembly to novel polysaccharide-polyacrylamide block copolymers namely pullulan-b-poly(N,N-dimethylacrylamide) (Pull-b-PDMA) and pullulan-b-poly(N-ethylacrylamide) (Pull-b-PEA). The bio-derived pullulan block was obtained via acid catalyzed depolymerisation, while the polyacrylamide homopolymer blocks were synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization. Subsequently the blocks were conjugated via copper catalyzed azide alkyne cycloaddition (CuAAC). The presence of formed vesicular structures was investigated via cryogenic electron microscopy (cryo SEM), static light ...
Suppliers List, E-mail/RFQ Form, Molecular Structure, Weight, Formula, IUPAC, Synonyms for (2-HYDROXYPROPANE-1,3-DIYL)BIS(OXYETHYLENE) BIS(DIHYDROGEN PHOSPHONATE),POTASSIUM SALT (CAS No. 94071-07-5)
A composition for delivery of a therapeutic agent is provided. The composition comprises: (a) a biocompatible block copolymer comprising one or more elastomeric blocks and one or more thermoplastic blocks and (b) a therapeutic agent, wherein the block copolymer is loaded with the therapeutic agent. The block copolymer is preferably of the formula X-(AB) n, where A is an elastomeric block, B is a thermoplastic block, n is a positive whole number and X is a seed molecule. The elastomeric blocks are preferably polyolefin blocks, and the thermoplastic blocks are preferably selected from vinyl aromatic blocks and methacrylate blocks. According to another aspect of the invention, a medical device is provided, at least a portion of which is insertable or implantable into the body of a patient. The medical device comprises (a) the above biocompatible block copolymer and (b) a therapeutic agent, wherein the block copolymer is loaded with the therapeutic agent. According to another aspect of the present invention
Looking for Block Copolymers? Find out information about Block Copolymers. polymers having macromolecules in which comparatively long sequences of the links of one monomer alternate with blocks of another monomer. The macromolecule... Explanation of Block Copolymers
Right here, we developed Pluronic? P123/N127 (poloxamer) combined micelles for the intravenous delivery of the anticancer drug sorafenib (SRB) or its combination with verteporfin (VP), a photosensitizer for photodynamic therapy that should go with well the cytotoxicity profile of the chemotherapeutic. cell-culture medium shown the superb stability of the system in physiologically relevant conditions. These results were in collection with the results of the launch study showing a launch rate of both medicines in the presence of healthy proteins slower than in phosphate buffer. SRB launch was sustained, while VP remained considerably entrapped in the micelle core. Cytotoxicity studies in MDA-MB231 cells exposed that at 24 hours, SRB-loaded micelles were more energetic than free of charge SRB just at extremely low SRB concentrations, while at 24+24 hours a lengthened cytotoxic impact of SRB-loaded micelles was noticed, extremely most likely mediated by the stop in RO5126766 manufacture the T stage ...
Right here, we developed Pluronic? P123/N127 (poloxamer) combined micelles for the intravenous delivery of the anticancer drug sorafenib (SRB) or its combination with verteporfin (VP), a photosensitizer for photodynamic therapy that should go with well the cytotoxicity profile of the chemotherapeutic. cell-culture medium shown the superb stability of the system in physiologically relevant conditions. These results were in collection with the results of the launch study showing a launch rate of both medicines in the presence of healthy proteins slower than in phosphate buffer. SRB launch was sustained, while VP remained considerably entrapped in the micelle core. Cytotoxicity studies in MDA-MB231 cells exposed that at 24 hours, SRB-loaded micelles were more energetic than free of charge SRB just at extremely low SRB concentrations, while at 24+24 hours a lengthened cytotoxic impact of SRB-loaded micelles was noticed, extremely most likely mediated by the stop in RO5126766 manufacture the T stage ...
Cytotoxicity assay. Cell viability was assessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (21). Cells were seeded into the 96-well microplates at 1 × 104 per well followed by IG-105 treatment at concentrations between 0 and 1 μmol/L for 72 h at 37°C. The supernatants were removed gently and cell viability was assessed. The plate was read in a microplate reader. The IC50 was determined in duplicates and each experiment was repeated at least three times under identical conditions. IC50 value was defined as the drug concentration that inhibits 50% cell growth compared with the untreated controls and calculated by regression analysis.. Pgp ATPase assay. Drug-stimulated activity of Pgp ATPase was detected by Pgp-Glo assay system (Promega). By following the user protocol provided by the vender, the activity of Pgp ATPase was measured in the presence or absence of 100 μmol/L Na3VO4, 200 μmol/L Verapamil (as a positive reference), 2 μmol/L vincristine, or 2 ...
SBR Co-Polymer Latex is a styrene butadiene copolymer latex for use as a Mortar/Rendering admixture which increases flexibility of cement screeds and mortars improves water and chemical resistance and increases durability Also used as a key Coat ...
TY - JOUR. T1 - Physical Characterization and Platelet Interactions under Shear Flows of a Novel Thermoset Polyisobutylene-based Co-polymer. AU - Sheriff, Jawaad. AU - Claiborne, Thomas E.. AU - Tran, Phat L.. AU - Kothadia, Roshni. AU - George, Sheela. AU - Kato, Yasushi P.. AU - Pinchuk, Leonard. AU - Slepian, Marvin J. AU - Bluestein, Danny. PY - 2015/10/7. Y1 - 2015/10/7. N2 - Over the years, several polymers have been developed for use in prosthetic heart valves as alternatives to xenografts. However, most of these materials are beset with a variety of issues, including low material strength, biodegradation, high dynamic creep, calcification, and poor hemocompatibility. We studied the mechanical, surface, and flow-mediated thrombogenic response of poly(styrene-coblock-4-vinylbenzocyclobutene)-polyisobutylene-poly(styrene-coblock-4-vinylbenzocylcobutene) (xSIBS), a thermoset version of the thermoplastic elastomeric polyolefin poly(styrene-block-isobutylene-block-styrene) (SIBS), which has ...
Unlike traditional monofilament, McCoy Premium Co-Polymer Fishing Line is formulated using a proprietary blend of nylon resins and infused with their PSP.
Dalton, AB, Coleman, JN, Panhuis, MIH, McCarthy, B, Drury, A, Blau, WJ, Paci, B, Nunzi, JM and Byrne, HJ (2001) Controlling the optical properties of a conjugated co-polymer through variation of backbone isomerism and the introduction of carbon nanotubes ...
Vesicles assembled from amphiphilic block copolymers represent promising nanomaterials for applications that include drug delivery and surface functionalization. One essential requirement to guide such polymersomes to a desired site in vivo is conjugation of active, targeting ligands to the surface of preformed self-assemblies. Such conjugation chemistry must fulfill criteria of efficiency and selectivity, stability of the resulting bond, and biocompatibility. We have here developed a new system that achieves these criteria by simple conjugation of 4-formylbenzoate (4FB) functionalized polymersomes with 6-hydrazinonicotinate acetone hydrazone (HyNic) functionalized antibodies in aqueous buffer. The number of available amino groups on the surface of polymersomes composed of poly-(dimethylsiloxane)-block-poly(2-methyloxazoline) diblock copolymers was investigated by reacting hydrophilic succinimidyl-activated fluorescent dye with polymersomes and evaluating the resulting emission intensity. To ...
In an infected wound, bacteria attack healthy cells by rupturing the outer cell wall through secreted protein toxins and enzymes. Scientists used the natural behaviour of bacterial pathogens to rupture biomimetic polymer nanocapsules and release antimicrobials and colorimetric signalling molecules. In other words, this novel dressing uses the pathogenic factors to liberate antimicrobials and indicating molecules from surface-immobilised nanocapsules. Thus, the nanocapsules provide a simple optical indicator of bacterial infection in burn wounds while killing any infection. BacterioSafe developed different types of nanocapsules and nanoparticles including phospholipid fatty acid vesicles, amphiphilic block copolymer systems, mini-emulsion polymerised nanocapsules and hybrid nanocapsules. To immobilise the nanocapsules onto the non-woven materials, partners investigated various methods including plasma surface modification, deposition of adhesive thin films and surface-attached hydrogels. The ...
The process of producing break-resistant and storage-stable detergent tablets comprising coating powdered or crystalline detergent components present in anhydrous form or having a low degree of hydration with a hydrophobicizing agent, and tabletting the resulting mixture under pressure to produce tablets having a breaking strength of at least 150 N.
Bicomponent fibers comprising a thermoplastic polymer and an elastomeric compound are made which can be continuously extruded from the melt at high production rates. The elastomeric compound has high flow and consists essentially of a selectively hydrogenated block copolymer and a tackifier resin, an alpha-olefin copolymer, an alpha-olefin terpolymer, a wax or mixtures thereof. In one embodiment the block copolymer has at least one polystyrene block of molecular weight from 5,000 to 7,000 and at least one polydiene block of molecular weight from 20,000 to 70,000 and having a vinyl content of greater than 60 mol %. In a second embodiment the block copolymer has a vinyl content of less than 60 mol %. The bicomponent fibers are useful for the manufacture of articles such as woven fabrics, spun bond non-woven fabrics or filters, staple fibers, yarns and bonded, carded webs.
Block copolymers wherein the first block contains from about 40 to about 65 mole percent of repeating units derived from glycolide randomly combined with from about 60 to 35 mole percent of repeating units derived from lactide and the second block contains repeating units derived from glycolide and repeating units derived from lactide, the second block containing a higher proportion of repeating units derived from glycolide than the first block, with units derived from glycolide constituting from about 75 to about 95 mole percent of the entire block copolymer are useful in forming surgical articles, including sutures.
Global Styrene-Butadiene-Styrene (SBS) Block Copolymer Market 2020-2024 The analyst has been monitoring the global styrene-butadiene-styrene (SBS) block copolymer market and it is poised to grow by 527.New York, Feb. 03, 2020 (GLOBE NEWSWIRE) -- Reportlinker.com announces the release of the report
PolySciTech (www.polyscitech.com) provides a wide array of biodegradable block copolymers including fluorescently conjugated block copolymers. These types
Product usage: Use to produce plastic goods which can withstand pressure, impacted resistance, no shrinkage…such as paint bucket, pesticide jars, plastic funiture …. Grades:. ...
O I- (D 09 ct o. Many commonly used phar- maceutical excipients such as the celluloses, pluronics, polysorbates, and povidones are acceptable stabilizers for generating physically stable nanoparticle dispersions (Liversidge and Cundy, 1995).
Page contains details about BSA/PDMAEMA-b-POEGMA block copolymer hybrid vesicles . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
The preparation of a branched, radial block copolymer having improved falling weight impact properties, and having trimodal distribution of molecular structure in the arms of the block copolymer is described.
My Dane survived because there was no torsion with either bloat, and no I do not have a home bloat kit. One warranted a trip to the emergency clinic and the other resolved itself with some careful monitoring and treatment at home under the advice of my vet. After his second unprovoked bloat he did have a profilactic gasteopexy (SP?) done and between that and putting his bowl back on the floor (which I am a strong believer in now)keeping him lean, and three feedings a day, he hasnt had any more issues with bloat. He definately is a survivor ...
Studies on a model ink suspension have shown that the effect of non-ionic dispersion agents on ink agglomeration using fatty acid chemistry as collector was highly temperature-dependent. The non-ionic surfactant reduced the agglomeration efficiency at low temperatures (below the cloud point of the surfactant) but this negative effect was reduced at increasing temperatures. At temperatures above the cloud point the non-ionic surfactant improved the agglomeration. The non-ionic surfactant adsorbs to both the ink and precipitated soap particles, which at low temperatures resulted in an increased colloidal stability of the particles but at higher temperatures led to a destabilisation of the particles due to the increased hydrophobicity of the surfactant. The surfactants clearly affected the precipitation of fatty acid anions to calcium soaps and at very high surfactant concentrations the formation of calcium soap particles was drastically reduced. The most favourable conditions seemed to be ...
Pluronic P123(PEG-PPG-PEG) symmetric triblock copolymer constitutes of poly(ethylene oxide)(PEO) and poly (propylene oxide) (PPO). The unique characteristic of PPO block exhibiting hydrophobicity at temperatures above 288K and solubility in water at temperatures below 288K lead to formation of micelle consisting of PEO-PPO-PEO triblock copolymers. Some studies report that the hydrophobic core contains PPO block, and a hydrophilic corona consists of PEO block. In 30wt% aqueous solution Pluronic P123® forms a cubic gel phase. Pluronic P-123 is the tradename for a triblock copolymer manufactured by the BASF Corporation. The nominal chemical formula is HO(CH2CH2O)20(CH2CH(CH3)O)70(CH2CH2O)20H, which corresponds to a molecular weight of around 5800 g/mol. Triblock copolymers based on poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) are known generically as poloxamer, and similar materials are manufactured by other companies. Poloxamers have behaviors similar to those of hydrocarbon ...
The susceptibility of ethoxylated non-ionic surfactants to oxidation on exposure to air was investigated. Surfactants have a complex chemical composition and are widely used in a variety of applications for to their amphiphilic properties. Ethoxylated non-ionic surfactants are regarded by the producers to be stable at normal handling. However, ethoxylated surfactants are polyethers and as such susceptible to oxidation on exposure to air, which is theoretically discussed in literature. Hand eczema is a common occupational disease of which mom than half of the cases is considered to be caused by work with surfactants and water. Surfactants are known to cause skin irritation, but cases of allergic contact dermatitis have also been reported.. Some ethoxylated surfactants were handled at room temperature in a manner that imitated ordinary handling at work. All samples autoxidized and the structures of some of the components formed were identified with liquid chromatography (HPLC) and gas ...
Overexpression of P-gp efflux pumps is believed to be responsible for multidrug resistance of mammalian cancer cells. Inhibition of these pumps is expected to increase the efficacy and decrease the toxicity of chemotherapeutic agents. The non-ionic triblock copolymer Pluronic P85 is reported to inhibit mammalian P-gp efflux pumps, leading to higher intracellular drug concentrations. An analogous, well-characterized efflux transporter, Pdr5p, has been identified in the yeast Saccharomyces cerevisiae, but the effect of Pluronic copolymers on this transporter has not been studied. We have examined the inhibitory effects of P85 on three strains of S. cerevisiae: a pdr5 deletion strain, a PDR5 over-expressing strain, and the PDR5 wild-type strain using the hydrophilic Pdr5p substrate cycloheximide (CHX) as a model antifungal "drug". Yeast cells were grown in the presence of a range of CHX (0-0.3 mcg/ml) and P85 (0-10 mg/ml). After incubation for 24hrs at 30°C, the ability of P85 to inhibit Pdr5 ...
Excessive mechanical loading to a joint has been linked with the development of posttraumatic osteoarthritis (OA). Among the suspected links between impact trauma to a joint and associated degeneration of articular cartilage is an acute reduction in chondrocyte viability. Recently, the non-ionic surfactant poloxamer 188 (P188) has been shown to reduce by approximately 50% the percentage of non-viable chondrocytes 24 hours post injury in chondral explants exposed to 25 MPa of unconfined compression. There is a question whether these acutely saved chondrocytes will continue to degrade over time, as P188 is only thought to act by acute repair of damaged cell membranes. In order to investigate the degradation of traumatized chondrocytes in the longer term, the current study utilized TUNEL staining to document the percentage of cells suffering DNA fragmentation with and without an immediate 24 hour period of exposure of the explants to P188 surfactant. In the current study, as in the previous study ...
0082]The 0.001 mol RAFT material (5.2 g) prepared in Embodiment 6 was put in a 250 mL round flask reactor in a nitrogen atmosphere, and dissolved in DMF (100 mL). Then, after AIBN radical initiator (1.0×10-4 mol) was poured into the reactor, the temperature was increased up to 90° C., and N-vinylimidazole (2 g) dissolved in DMF (20 mL) was poured into the reactor. After a 24-hour reaction, sulfon amide methacrylamide monomer (2 g) dissolved in DMF (20 mL) was additionally poured into the reactor through a syringe, and was polymerized during 24 hours. After the polymerization reaction, N-phenylmaleimide (2 g) dissolved in DMF (20 mL) was poured into the reactor through a syringe, and reacted during 24 hours, to thereby synthesize polyethylene oxide block co-polymer (10 g). The molecular weight of the product was 11,200 g/mol according to the nuclear magnetic resonance spectral analysis ...
3,4-Dihydroxyphenyl-l-alanine (DOPA) is an unusual amino acid found in mussel adhesive proteins (MAPs) that is believed to lend adhesive characteristics to these proteins. In this paper, we describe a route for the conjugation of DOPA moieties to poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide) (PEO−PPO−PEO) block copolymers. Hydroxyl end groups of PEO−PPO−PEO block copolymers were activated by N,N-disuccinimidyl carbonate and then reacted with DOPA or its methyl ester with high coupling efficiencies from both aqueous and organic solvents. DOPA-modified PEO−PPO−PEO block copolymers were freely soluble in cold water, and dye partitioning and differential scanning calorimetry analysis of these solutions revealed that the copolymers aggregated into micelles at a characteristic temperature that was dependent on block copolymer composition and concentration in solution. Oscillatory rheometry demonstrated that above a block copolymer concentration of approximately 20 wt ...
0210]Nonionic surfactants considered within the scope of the invention include alkylglucosides; alkylmaltosides; alkylthioglucosides; lauryl macrogolglycerides; poly-oxyalkylene ethers; polyoxyalkylene alkyl ethers; polyoxyalkylene alkylphenols; polyoxyalkylene alkyl phenol fatty acid esters; polyethylene glycol glycerol fatty acid esters; polyglycerol fatty acid esters; polyoxyalkylene sorbitan fatty acid esters; sorbitan fatty acid esters; hydrophilic transesterification products of a polyol with at least one member of the group consisting of glycerides, vegetable oils, hydrogenated vegetable oils, fatty acids, and sterols; polyoxyethylene sterols, derivatives, and analogues thereof; polyoxyethylated vitamins and derivatives thereof; polyoxyethylene-polyoxypropylene block copolymers, PEG-10 laurate, PEG-12 laurate, PEG-20 laurate, PEG-32 laurate, PEG-32 dilaurate, PEG-12 oleate, PEG-15 oleate, PEG-20 oleate, PEG-20 dioleate, PEG-32 oleate, PEG-200 oleate, PEG-400 oleate, PEG-15 stearate, ...
Ciprofloxacin is preferred to be used in acidic medium because of its poor solubilisation in neutral medium. To observe the solubilisation of ciprofloxacin in neutral medium through a pluronic mixed micellar system this study was undertaken. A binary mixture comprising Pluronic F108 and Pluronic L81 has been utiliz
Poly(acrylic acid) (PAA) was attached on both termini of Pluronic P85 copolymer (EO27PO39EO27)) via atom transfer radical polymerization (ATRP) to produce a novel block copolymer, PAA-b-P85-b-PAA (P85PAA). The P85PAA-DOX complex formation and drug loading were strongly dependent on the PAA segment and pH, where the protonation of the carboxyl groups in the PAA segment at pH,7.2 reduced the binding sites of DOX onto P85PAA chains, resulting less DOX uptake at low pH. The composition of the copolymer-DOX complexes that at pH 7.2 was close to the stoichiometric (1:1 mol Dox:carboxyl ratio), indicating the dominance of the electrostatic interactions between cationic DOX molecules and carboxyl groups. DOX loading at pH 5.0 reduced to 0.6:1 molar ratio of DOX:carboxyl indicated that protonation of the carboxyl reduced the DOX binding to the P85PAA block copolymer. DOX release from the complex is highly pH-responsive process, where 57% of encapsulated DOX was released in 30h at pH7.2, and the ...
Despite the growing interest in amphiphilic block copolymers for their application in micelles as ideal drug delivery carriers, there remain some challenges related to biocompatibility, stability, degradability, and loading efficiency of the micelles. Herein, we report a novel hydrophobic, pH-responsive epoxide monomer, tetrahydropyranyl glycidyl ether (TGE). Anionic ring-opening polymerization affords the controlled synthesis of a series of its homopolymers (PTGE) and amphiphilic polymers, poly(ethylene glycol)-block-poly(tetrahydropyranyl glycidyl ether) (PEG-b-PTGE). Interestingly, these block copolymers with cyclic TGE moieties showed superior stability in biological media, high loading capacity, tunable release, and controllable degradation compared to the block copolymers with its acyclic analogue, 1-ethoxyethyl glycidyl ether (EEGE), widely employed in polyether, which satisfy all the required design principles and address the challenges in drug delivery systems. The superior ...
A Niosome is a non-ionic surfactant-based Vesicle (biology and chemistry). Niosomes are formed mostly by non-ionic surfactant and cholesterol incorporation as an excipient. Other excipients can also be used. Niosomes have more penetrating capability than the previous preparations of emulsions. They are structurally similar to liposomes in having a bilayer, however, the materials used to prepare niosomes make them more stable. Niosomes are lamellar structures that are microscopic in size. They constitute of non-ionic surfactant of the alkyl or dialkyl polyglycerol ether class and cholesterol with subsequent hydration in aqueous media. The surfactant molecules tend to orient themselves in such a way that the hydrophilic ends of the non-ionic surfactant point outwards, while the hydrophobic ends face each other to form the bilayer. The figure in this article on Niosomes gives a better idea of the lamellar orientation of the surfactant molecules. Niosomes are osmotically active, chemically stable ...
Angewandte Chemie Channels in Micelles DOI: 10.1002/ange.200600172 Formation of Complex Micelles with DoubleResponsive Channels from Self-Assembly of Two Diblock Copolymers** Guiying Li, Linqi Shi,* Rujiang Ma, Yingli An, and Nan Huang The establishment of an effective method to prepare desirable nanostructures and to eventually convert them into designed architectures is of increasing interest in nanotechnology, chemistry, and biology. Proteins that are located in the phospholipid bilayer of cell membranes are important in forming transient pores or channels to achieve ion transport, ion regulation, energy transduction, signal recognition, and other biological processes. Numerous functional materials, including nanoporous membranes and synthetic transmembrane channels, have been designed based on these important gating structures in order to mimic biological processes.[1-4] It is now well established that amphiphilic block copolymers can self-assemble into lipid-like membranes with tunable ...
Method of Preparation: Calculate the quantity of each ingredient for the amount to be prepared. Accurately weigh or measure each ingredient. Add the estradiol powder to the propylene glycol and mix well. Add the Pluronic P105 and the water to the mixture and mix well. Package and label.. Use: Estradiol vaginal solution has been used for the treatment of atrophic vaginitis, atrophic dystrophy of the vulva, menopausal symptoms, female hypogonadism, and mild-to-severe vasomotor symptoms associated with menopause.. Packaging: Package in tight, light-resistant containers.. Labeling: Keep out of the reach of children. For vaginal use. Use only as directed. Discard after ____ [time period].. Stability: A beyond-use date of 30 days may be used for this preparation.1. Quality Control: Quality-control assessment can include weight/volume, pH, specific gravity, active drug assay, color, clarity, rheologic properties/pourability, physical observation, and physical stability (discoloration, foreign ...
Article Tri-Mer Co-polymer Tanks Were Recently Chosen for a Major Stainless Steel Processing Line in Pohang, South Korea. The line provides continuous annealing and pickling of stainless coils,
Analysis of cell motility effects in physiological processes can be facilitated by a mathematical model capable of simulating individual cell movement paths. A quantitative description of motility of individual cells would be useful, for example, in the study of the formation of new blood vessel networks in angiogenesis by microvessel endothelial cell (MEC) migration. In this paper we propose a stochastic mathematical model for the random motility and chemotaxis of single cells, and evaluate migration paths of MEC in terms of this model. In our model, cell velocity under random motility conditions is described as a persistent random walk using the Ornstein-Uhlenbeck (O-U) process. Two parameters quantify this process: the magnitude of random movement accelerations, alpha, and a decay rate constant for movement velocity, beta. Two other quantities often used in measurements of individual cell random motility properties-cell speed, S, and persistence time in velocity, Pv-can be defined in terms of ...
The blood-brain barrier is a substantial obstacle for delivering anticancer agents to brain tumors, and new strategies for bypassing it are sorely needed for brain tumor therapy. Intranasal delivery provides a practical, noninvasive method for delivering therapeutic agents to the brain. Intranasal application of nano-sized micelles that have been modified with Tat peptide facilitates brain delivery of fluorescent model materials. In this study, we evaluated a nose-to-brain delivery system for brain tumor therapy. We nasally administered the anti-tumor drug camptothecin (CPT) in solution and in methoxy poly(ethylene glycol) (MPEG)/poly(e-caprolactone) (PCL) amphiphilic block copolymers (MPEG-PCL) and cell penetrating peptide, Tat analog-modified MPEG-PCL (MPEG-PCL-Tat) MPEG-PCL-Tat to rats bearing intracranial glioma tumors and quantified the cytotoxicity against glioma cells, and the therapeutic effects. CPT-loaded MPEG-PCL-Tat micelles showed higher cytotoxicity than CPT-loaded MPEG-PCL. CPT-free MPEG
Prevalent research underscores efforts to engineer highly sophisticated nano-vesicles that are functionalized to combat antibiotic-resistant bacterial infections, especially those caused by methicillin-resistant Staphylococcus aureus (MRSA), and that aid with wound healing or immunomodulation. This is especially relevant for patients who are susceptible to S. aureus infections post-operatively. Technical challenges associated with this aim require a thorough assessment of the chemical properties of synthesis materials and methods. Here, formulations were incorporated into polymeric, biocompatible vesicles called polymersomes that self-assemble via hydrophobicity interactions of admixed aqueous and organic substances. Nano-polymersomes were synthesized using a high molecular weight amphiphilic block copolymer, and were conjugated to include antimicrobial peptides (AMPs) along the peripheral hydrophilic region and silver (Ag) nanoparticles inside their hydrophobic corona. In vitro testing on ...
A block copolymer comprising a fluorinated block and a non-fluorinated block and method of making the block copolymer are provided. Also provided herein are a coating on an implantable device comprising the block copolymer and method of using the implantable device.
A block copolymer comprising a fluorinated block and a non-fluorinated block and method of making the block copolymer are provided. Also provided herein are a coating on an implantable device comprising the block copolymer and method of using the implantable device.
The invention relates to emulsions comprising two non-aqueous, immiscible liquids, (L1) and (L2), whereby the liquid (L1), which is either the continuous or dispersed phase of the emulsion, is a silicone. The emulsion is further stabilized by at least one graft or block co-polymer of which one fraction is soluble in the dispersed phase the other in the continuous phase, the fraction soluble in the continuous phase being greater than the fraction soluble in the dispersed phase. The invention further relates to dispersions of said emulsions in an aqueous or organic phase and use of said emulsions and dispersions in the field of cosmetic and/or dermatological formulations
Acinetobacter baumannii is a Gram-negative opportunistic human pathogen known to cause a range of infections in hospitals. Despite their recent emergence, strains of A. baumannii, resistant to essentially all routinely used antibiotics, have been isolated from clinical settings. Bioinformatic analysis identified more than 50 transporter systems with a putative role in drug efflux in the genome of A. baumannii ATCC17978, representing ~2% of all its protein coding ORFs. Based on an assumption that drug transport is often associated with over-expression of a relevant efflux system in the presence of the substrate, high-throughput quantitative reverse-transcriptase PCR (qRT-PCR) has been performed after shock treatments with sub-inhibitory concentrations of antibiotics and differential expression of genes was assessed. This strategy has led to the discovery of novel drug efflux systems and defined physiological functions for previously characterised and novel pumps in drug resistance ...