Synperonic F108 Research Articles

Development of Antifouling Polysulfone Membranes by Synergistic Modification with Two Different Additives in Casting Solution and Coagulation Bath: Synperonic F108 and Polyacrylic Acid.

This study deals with the development of antifouling ultrafiltration membranes based on polysulfone (PSF) for wastewater treatment and the concentration and purification of hemicellulose and lignin in the pulp and paper industry. The efficient simple and reproducible technique of PSF membrane modification to increase antifouling performance by simultaneous addition of triblock copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol (Synperonic F108, Mn =14 × 103 g mol−1) to the casting solution and addition of polyacrylic acid (PAA, Mn = 250 × 103 g mol−1) to the coagulation bath is proposed for the first time. The effect of the PAA concentration in the aqueous solution on the PSF/Synperonic F108 membrane structure, surface characteristics, performance, and antifouling stability was investigated. PAA concentrations were varied from 0.35 to 2.0 wt.%. Membrane composition, structure, and topology were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The addition of PAA into the coagulation bath was revealed to cause the formation of a thicker and denser selective layer with decreasing its pore size and porosity; according to the structural characterization, an interpolymer complex of the two additives was formed on the surface of the PSF membrane. Hydrophilicity of the membrane selective layer surface was shown to increase significantly. The selective layer surface charge was found to become more negative in comparison to the reference membrane. It was shown that PSF/Synperonic F108/PAA membranes are characterized by better antifouling performance in ultrafiltration of humic acid solution and thermomechanical pulp mill (ThMP) process water. Membrane modification with PAA results in higher ThMP process water flux, fouling recovery ratio, and hemicellulose and total lignin rejection compared to the reference PSF/Synperonic F108 membrane. This suggests the possibility of applying the developed membranes for hemicellulose concentration and purification.

The Modification of Polyethersulfone Membranes Using a Synperonic F108 Block Copolymer and Their Application for the Fractionation of Thermomechanical Pulp Mill Process Water

The effect of additions of a Synperonic F108 amphiphilic triblock copolymer of poly(ethylene oxide) and poly(propylene oxide) to casting solutions on the structure and properties of polyethersulfone (PES) membranes was studied. It is found that the introduction of small amounts (0.3–0.5%) of Synperonic F108 leads to an increase in the pure water flux of membranes from 50 up to 120–200 L m−2 h−1 at the same time membranes showed constant selectivity and enhanced hydrophilicity. The water contact angle decreases from 65° down to 41°–42°. Infrared (IR) spectroscopic studies show that Synperonic F108 is predominantly localized on the selective layer of membranes. The investigation of the morphology of membranes by scanning electron microscopy (SEM) shows that the introduction of Synperonic F108 promotes an increase in the total width of the transition layer and suppressed the macrovoids formation in the membranes supporting layer. Modified membranes are tested in the process of fractionation of thermomechanical pulp mill process water in order to isolate hemicelluloses for further processing. It is shown that the modified membranes obtained with the addition of 0.5% Synperonic F108 are characterized by two- to sixfold higher flux and 40% higher flux recovery ratio. The hemicellulose rejection for the initial and modified membranes varies within 95–97%, while lignin rejection is slightly lower in the case of modified membranes (14–19%, 21% for the nonmodified membrane).

Influence of anionic and non-ionic surfactants on nanoparticle synthesis by solvent-free extrusion emulsification

This study examines the impact of surfactants on the mechanism of a new solvent-free extrusion emulsification (SFEE) technique. Two sets of surfactants were used in this work, three anionic (SDBS, Unicid 350, Calfax DB-45) and three non-ionic (Igepal CO-890, Brij 58, Synperonic F-108). Of the anionic surfactants, only SDBS and Calfax were found to create stable O/W emulsions with a polyester in the desired 100–200 nm size range; the latter requiring a lower molar concentration. Igepal CO-890 and Brij 58 resulted in only partial emulsification despite requiring higher molar loadings than their anionic counterparts to accomplish this outcome, with majority of the polymer leaving the extruder without phase inverting. The study reinforced previous findings that the dispersion stage (zone) controls the SFEE technique, and highlighted the importance of water affinity displayed by a surfactant species to compensate for high retarding viscous force for mixing water into the polymer melt.

PGE2 and Poloxamer Synperonic F108 Enhance Transduction of Human HSPCs with a β-Globin Lentiviral Vector

Lentiviral vector (LV)-based hematopoietic stem and progenitor cell (HSPC) gene therapy is becoming a promising alternative to allogeneic stem cell transplantation for curing genetic diseases. Clinical trials are currently underway to treat sickle cell disease using LVs expressing designed anti-sickling globin genes. However, because of the large size and complexity of the human β-globin gene, LV products often have low titers and transduction efficiency, requiring large amounts to treat a single patient. Furthermore, transduction of patient HSPCs often fails to achieve a sufficiently high vector copy number (VCN) and transgene expression for clinical benefit. We therefore investigated the combination of two compounds (PGE2 and poloxamer synperonic F108) to enhance transduction of HSPCs with a clinical-scale preparation of Lenti/G-AS3-FB. Here, we found that transduction enhancers increased the in vitro VCN of bulk myeloid cultures ∼10-fold while using a 10-fold lower LV dose. This was accompanied by an increased percentage of transduced colony-forming units. Importantly, analysis of immune-deficient NSG xenografts revealed that the combination of PGE2/synperonic F108 increased LV gene transfer in a primitive HSC population, with no effects on lineage distribution or engraftment. The use of transduction enhancers may greatly improve efficacy for LV-based HSPC gene therapy.

Ammonium tagged Hoveyda-Grubbs catalysts immobilized on magnetically separable core-shell silica supports for ring-closing metathesis reactions

Ammonium tagged Hoveyda-Grubbs (Ru-1) catalyst was immobilized on core-shell structured silica gel bearing a magnetic nano-sized α-Fe2O3 core via non-covalent interactions. Core-shell silica gel materials were synthesized using a two-step coating procedure of α-Fe2O3 in the presence of cationic (dodecyl trimethyl ammonium chloride, DTMAC) and non-ionic (Synperonic F108) surfactants and tetraethoxysilane (TEOS) as the silica source. Double SiO2 coated SiO2(2)@α-Fe2O3 supports with a high surface area of 646 m2/g and pore size/volumes of 2.88 nm/0.393 cm3 were obtained after removal of template surfactants from silica gel by extraction. Supported catalyst, Ru-1@SiO2(2)@α-Fe2O3, was found to be very active in ring-closing metathesis (RCM) reactions of diethyl diallyl malonate (DEDAM) and various dienes. The catalyst can be easily separated from the reaction mixture with the aid of a magnet and was reusable up to eight times with low Ru leaching levels.

Abstract 4144: Improvement of tumor cell transduction with lentiviral vectors using chemical and cell targeting approaches.

Abstract Although lentiviral transduction methods are widely used in cancer research their application is frequently hindered by the low transduction efficiency seen for a number of different cell types, in particular primary cells. We have previously reported that a mixture of poloxamer synperonic F108 and polybrene combines reduced toxicity and increased lentiviral gene delivery into a range of different primary cell cultures (1). We now report further improvement in efficiency through a novel combination of the poloxamer-based adjuvant with a modified lentiviral envelope. The envelope was rendered cell specific by fusing monoclonal antibody fragments directed against specific cell-surface epitopes with the viral attachment glycoprotein VSV-G. For specific cellular targeting we inserted chimeric antiCD30 or antiEGFR antibody-VSV-G fusion proteins into the lentiviral genome. The combination of VSV-G-fused antibody fragments against specific tumor cell antigens and the improved adjuvant resulted in a 3-fold higher transduction rate using a GFP reporter containing lentivirus in CD30-positive lymphoma and EGFR-positive epithelial breast cancer cells. The combination of optimized transduction enhancer molecules and retargeted lentiviral vectors enabled quantitative transduction of previously hard-to-transduce cell types. When mixtures of antigen-negative and antigen-positive tumor cells were selected the modified lentivirus particles showed a preference for infecting antigen-positive cells by a factor 4. These results demonstrate that improvements in both chemical charge protecting adjuvants and membrane targeting can lead to increased transduction efficiency without a loss of specificity. The combination of chemical adjuvant and envelope design can lead to the optimization of lentiviral transductions in large-scale systems. *1. Höfig I, Atkinson MJ, Mall S, Krackhardt AM, Thirion C, Anastasov N. Poloxamer synperonic F108 improves cellular transduction with lentiviral vectors. J Gene Med. 2012 Aug;14(8):549-60. Citation Format: Ines Höfig, Michael J. Atkinson, Christian Thirion, Natasa Anastasov. Improvement of tumor cell transduction with lentiviral vectors using chemical and cell targeting approaches. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4144. doi:10.1158/1538-7445.AM2013-4144

Poloxamer synperonic F108 improves cellular transduction with lentiviral vectors

Although lentiviral transduction methods are widely used, their broader application is dependent upon the optimization of lentiviral transduction efficiency for a broad range of cell types. In the present study, we focus on the evaluation of two chemical classes with respect to their ability to increase lentiviral transduction without cytotoxicity. We compared the activity of adjuvants that are already used for lentivirus delivery with that of novel adjuvants selected on the basis of their chemical and physical characteristics. The novel poloxamer synperonic F108 demonstrated superior characteristics for enhancing lentiviral transduction over the best-in-class polybrene-assisted transduction. The results revealed that poloxamer synperonic F108 exhibited the dual benefits of low toxicity and a high efficiency of lentiviral gene delivery into a range of different primary cell cultures. In the presence of poloxamer synperonic F108, cells showed an increased propidium dye influx indicating a re-organization of membrane microstructures accompanying lentivirus uptake. The administration of a mixture of poloxamer synperonic F108 with polybrene further enhanced lentiviral transduction rates. The results obtained in the present study indicate that a contribution to efficiency is made by each adjuvant, with polybrene acting as a charge protector and poloxamer synperonic F108 as a membrane modulator. Therefore, poloxamer synperonic F108, either alone or in combination, can lead to the optimization of large-scale lentiviral transduction approaches.

Phase behavior and dynamics of a micelle-forming triblock copolymer system

Synperonic F-108 (generic name, "pluronic") is a micelle forming triblock copolymer of type ABA , where A is polyethylene oxide (PEO) and B is polypropylene oxide (PPO). At high temperatures, the hydrophobicity of the PPO chains increase, and the pluronic molecules, when dissolved in an aqueous medium, self-associate into spherical micelles with dense PPO cores and hydrated PEO coronas. At appropriately high concentrations, these micelles arrange in a face centered cubic lattice to show inverse crystallization, with the samples exhibiting high-temperature crystalline and low-temperature fluidlike phases. By studying the evolution of the elastic and viscous moduli as temperature is increased at a fixed rate, we construct the concentration-temperature phase diagram of Synperonic F-108. For a certain range of temperatures and at appropriate sample concentrations, we observe a predominantly elastic response. Oscillatory strain amplitude sweep measurements on these samples show pronounced peaks in the loss moduli, a typical feature of soft solids. The soft solidlike nature of these materials is further demonstrated by measuring their frequency-dependent mechanical moduli. The storage moduli are significantly larger than the loss moduli and are almost independent of the applied angular frequency. Finally, we perform strain rate frequency superposition experiments to measure the slow relaxation dynamics of this soft solid.

Foam and wetting films from amphiphilic block copolymers: Isoelectric state and stability

Foam and wetting films from PEO-PPO-PEO triblock copolymers Synperonic P85 and F108 are studied under the identical conditions, using microinterference method. The range of background electrolyte concentration, where DLVO (electrostatic and van der Waals) forces and non-DLVO (steric) forces act in the films, is determined. From the dependence of the film thickness on pH, it is unambiguously shown that electrostatic interactions (i.e., the potential and surface charge) in the foam and wetting films caused by the presence of nonionic polymer surfactants arise due to the preferential adsorption of OH− ions at the solution-air interface. The films obtained below the critical pH values are sterically stabilized; i.e., a decrease in pH induces a transition from electrostatic to steric stabilization. Three-layer models are designed for both types of films that allow to calculate electrostatic disjoining pressure Πel. The values of ϕ0 potential of the foam film are used to calculate Πel in wetting films. A relation between the isoelectric state of foam and wetting films and their stability is found to exist in the range of pH corresponding to electrostatic stabilization. Metastable films, film rupture, or the transition to sterically stabilized films were also found.

Mixed micelles containing lipophilic gadolinium complexes as MRA contrast agents.

Mixed micelles for MRA are multicomponent systems containing a phospholipid, a biocompatible non-ionic surfactant (e.g. Synperonic(R) F-108) and a lipophilic gadolinium complex. A variety of lipophilic gadolinium complexes were designed taking into account features such as: (i) nature of ligand (cyclic versus acyclic); (ii) lipophilic moiety; (iii) global charge of the complex; and (iv) nature of bond connecting the complex to the lipophilic moiety. All the lipophilic gadolinium complexes after formulation as mixed micelles show high relaxivities in water and in blood (rat). Mixed micelles containing gadolinium complexes bearing only one aliphatic chain cannot be used as MRA contrast agents because they have a high haemolytic effect. Furthermore, in rats they are quickly eliminated from the blood stream. These drawbacks are completely circumvented using gadolinium complexes bearing two aliphatic chains. Mixed micelles containing such complexes show high relaxivities, no haemolytic effect and long blood permanence. This makes them promising candidates as MRA contrast agents. However, elimination, which occurs exclusively through the liver, is not complete, even after 7 days. Complexes containing labile (e.g. ester) bonds between the lipophilic moieties and the chelate subunit are eliminated through both the liver and the kidneys. However, elimination is still not complete after 7 days.

FOAMABILITY OF PEO-PPO-PEO TRIBLOCK COPOLYMERS (P85 AND F108) AND ROLE OF THE FOAM FILMS

ABSTRACT The foamability of two commercial PEO-PPO-PEO triblock copolymers (Synperonic P85 and F108, ICI) was studied and compared to the properties of single foam films. The volume of a steady-state foam column created with a combined pneumatic-mechanical device is used as a measure of the copolymers foamability. Experiments were carried out at bulk copolymer concentrations corresponding to full surface coverage, i.e. constant area per molecule, under equilibrium conditions. The foamability of F108 solutions was higher than that of P85 although the surface activity of both copolymers was similar. The foam volume increases with increasing the bulk copolymer concentration. Higher electrolyte concentration or lower pH caused the foam volume to diminish. A pronounced parallelism between the properties of dynamic foams and single microscopic foam films was observed: when thicker single foam films were formed (from F108 solutions) the steady

Transition from electrostatic to steric stabilization in foam films from ABA triblock copolymers of poly(ethylene oxide) and poly(propylene oxide)

The equilibrium thickness of microscopic foam films obtained from aqueous solutions of two different poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) triblock copolymers (Synperonic PE P85 and F108) is experimentally determined. The amphiphilic triblock copolymers adsorb at the air/solution interface as a brush layer. The foam film may be stabilized by electrostatic and/or steric repulsion. At a given copolymer concentration (slightly lower than the CMC) increasing the electrolyte concentration induces a transition from electrostatic to steric stabilization. The thicker foam films are electrostatically stabilized. The thinnest foam films are sterically stabilized, but their thickness is unexpectedly larger than twice the brush layer thickness. While the thickness h of these films strongly depends on the degree of polymerization N, its scaling structure is essentially the same: two brush layers ( h 1 ∼ N) and an aqueous core ( h 2 ∼ N 3/5). The microscopic foam film is a suitable tool for exploring the transition from electrostatic to steric stabilization.

Poloxamer sorption on liposomes: comparison with polystyrene latex and influence on solute efflux

The adsorption characteristics of several polyoxyethylene-polyoxypropylene (POE-POP) block copolymers (Synperonics) were studied on both polystyrene microspheres and small unilamellar vesicles (SUVs) composed of egg phosphatidylcholine (egg PC). Photon correlation spectroscopy (PCS) was used to monitor the increase in hydrodynamic radius following polymer sorption. Apparent adsorbed layer thickness (δ) of all POE-POP block copolymers was shown to be Langmurian. This δ increased non-linearly with the molecular weight of the polymer. Adsorption of Synperonic F108 occurred rapidly onto latex particles with no subsequent change of hydrodynamic radius on storage. For SUVs, δ was significantly less ( P < 0.05) than that measured for the same polymer with polystyrene microspheres, which may indicate a degree of bilayer penetration by the polymers. The efflux rate of entrapped 6-carboxyfluorescein (6-CF) was considerably lower for SUVs prepared from egg PC and cholesterol (1 : 1 molar ratio) than for those prepared from egg PC alone when suspended in Synperonic F108. Retention of 6-CF was higher for multilamellar vesicles (MLVs) than for SUVs when incubated in the same polymer solution.