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This study focused on synthesis of anionic magnetite nanoparticles (MNPs) immobilized with a bisphenol A (BPA)-specific peptide aptamer for selective BPA adsorption. The MNP surface was coated with anionic poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) to provide water dispersibility and stability. These nanosorbents, with a saturation magnetization value of 47 emu/g, responded well to the change in zeta potential and hydrodynamic size with varying dispersion pH. The aptamer loading capacity of particles was 0.12 mg/mg MNPs, and the nanosorbents exhibited a 47% BPA adsorption capacity. Importantly, they shown high selectivity in capturing BPA over structurally similar molecules. [ABSTRACT FROM AUTHOR]

IntroductionHeavy metals such as lead, aluminum, mercury, copper, cadmium, nickel, and arsenic are now commonly found worldwide. Among these, cadmium and lead are the most hazardous, posing significant risks to both the environment and human health. Cleaning soils contaminated with organic and inorganic contaminants is one of the most significant and fundamental challenges facing society today. One effective method for soil purification is to extract or immobilize the contaminant within the soil. Materials and MethodsIt is unclear how water-soluble polymers contribute to the immobilization of heavy metals. The purpose of this study is to examine how various polymers affect the immobilization of lead, zinc, and cadmium in the soil near a lead and zinc mine in the province of Zanjan. A factorial experiment with three replications was conducted using a randomized complete block design. The experimental treatments included one type of soil and three different kinds of acrylic polymers (cationic, nonionic, and anionic) applied at four different levels (0, 0.05, 0.1, and 0.2). The absorbable amounts of lead, zinc, and cadmium were tested at various intervals after the polymers were applied to the soil samples. After that, SAS statistical software was used to examine the data. To do this, the Duncan multiple range test was used to compare the means. The necessary tables and graphs were then created using Excel. Results and DiscussionThe findings demonstrated that, at 1% probability level, the kind of polymer had a considerable impact on the amount of lead, zinc, and cadmium that may be absorbed in the soil. The average concentration of soil-absorbable lead for the different types of polymers employed was 239.8, 260.15, and 267.65 mg/kg; anionic polymer had the lowest concentration. Stated differently, anionic polymer decreases the capacity to absorb lead and stabilizes more lead in the soil than the other two forms of polymer. Anionic polymers most likely have a stronger impact on soil granulation. Additionally, at 1% probability level, the impact of acrylic polymer intake on the amount of lead, zinc, and cadmium absorbable in the soil was considerable. With an increase in the amount of polymer utilized in the soil, the greatest absorbable lead concentration (301.58 mg/kg) in the control treatment dropped to the lowest absorbable lead concentration (0.2). It was possible to determine the polymer percentage and the lead concentration, which came out to be 205.9 mg/kg of soil. Zinc concentration dropped as acrylic polymer consumption increased; in the control treatment, absorbable zinc concentrations ranged from 0.2 to 83.5 mg/kg of soil, with 0.2 being the highest concentration. At 1% probability level, the impact of the polymer's contact time with the soil on the amount of lead, zinc, and cadmium that the soil may absorb was significant. As a result, the tested soil had 414.52 mg of these elements at the initial stage of polymer treatment. The quantity of absorbable lead in the soil became 66% immobilized after a month, and after 720 hours, the amount of absorbable lead dropped to 141.83 mg/kg. As the polymer's contact time with the soil increased, so did the concentration of absorbable zinc in the soil. At 1% probability level, there was a strong correlation between the kind and amount of acrylic polymers and the amount of lead, zinc, and cadmium that may be absorbed in the soil. The ingestion of 0.2% anionic polymer resulted in the largest amount of lead immobilization, lowering the soil's absorbable lead concentration from 300 to 192 mg/kg of soil. A higher amount of anionic polymer immobilized the lead, and both cationic and non-ionic polymers were positioned after it. Additionally, anionic polymer was more prevalent than cationic polymer. It caused the non-ionic polymer's absorbable zinc to become immobile. Following 720 hours of polymer treatment, the soil's absorbable zinc element was immobilized to a greater extent by the anionic polymer (20%) than by the cationic and non-ionic polymers (26%), respectively. In comparison to the original concentration, the largest amount of immobilization by anionic polymer after one month was 78%, and the lowest amount of immobilization by nonionic polymer was 61%. Anionic polymer was 27% more effective than non-ionic polymer, 18% more effective than cationic polymer, and stabilized more cadmium. Conclusion The results of this study showed that with increasing the duration of contact of polymers used with the soil, the amount of mobility of heavy metals in the soil decreased and also with increasing the amount of polymer consumption, the rate of metal stabilization in the soil increased. Anionic polymers immobilize more lead, zinc and cadmium in soil. To reduce the mobility of lead, zinc and cadmium and improve the stability and increase aggregation in soil, the use of acrylic polymer in contaminated soil is recommended.

IntroductionHeavy metals such as lead, aluminum, mercury, copfa, cadmium, nickel, and arsenic are now commonly found worldwide. Among these, cadmium and lead are the most hazardous, posing significant risks to both the environment and human health. Cleaning soils contaminated with organic and inorganic contaminants is one of the most significant and fundamental challenes facing society today. One effective method for soil purification is to extract or immobilize the contaminant within the soil. Materials and MethodsIt is unclear how water-soluble polymers contribute to the immobilization of heavy metals. The purpose of this study is to examine how various polymers affect the immobilization of lead, zinc, and cadmium in the soil near a lead and zinc mine in the province of Zanjan. A factorial exfaiment with three replications was conducted using a randomized complete block design. The exfaimental treatments included one type of soil and three different kinds of acrylic polymers (cationic, nonionic, and anionic) applied at four different levels (0, 0.05, 0.1, and 0.2). The absorbable amounts of lead, zinc, and cadmium were tested at various intervals after the polymers were applied to the soil samples. After that, SAS statistical software was used to examine the data. To do this, the Duncan multiple range test was used to compare the means. The necessary tables and graphs were then created using Excel. Results and DiscussionThe findings demonstrated that, at 1% probability level, the kind of polymer had a considerable impact on the amount of lead, zinc, and cadmium that may be absorbed in the soil. The average concentration of soil-absorbable lead for the different types of polymers employed was 239.8, 260.15, and 267.65 mg/kg; anionic polymer had the lowest concentration. Stated differently, anionic polymer decreases the capacity to absorb lead and stabilizes more lead in the soil than the other two forms of polymer. Anionic polymers most likely have a stronger impact on soil granulation. Additionally, at 1% probability level, the impact of acrylic polymer intake on the amount of lead, zinc, and cadmium absorbable in the soil was considerable. With an increase in the amount of polymer utilized in the soil, the greatest absorbable lead concentration (301.58 mg/kg) in the control treatment dropped to the lowest absorbable lead concentration (0.2). It was possible to determine the polymer facentage and the lead concentration, which came out to be 205.9 mg/kg of soil. Zinc concentration dropped as acrylic polymer consumption increased; in the control treatment, absorbable zinc concentrations ranged from 0.2 to 83.5 mg/kg of soil, with 0.2 being the highest concentration. At 1% probability level, the impact of the polymer's contact time with the soil on the amount of lead, zinc, and cadmium that the soil may absorb was significant. As a result, the tested soil had 414.52 mg of these elements at the initial stage of polymer treatment. The quantity of absorbable lead in the soil became 66% immobilized after a month, and after 720 hours, the amount of absorbable lead dropped to 141.83 mg/kg. As the polymer's contact time with the soil increased, so did the concentration of absorbable zinc in the soil. At 1% probability level, there was a strong correlation between the kind and amount of acrylic polymers and the amount of lead, zinc, and cadmium that may be absorbed in the soil. The ingestion of 0.2% anionic polymer resulted in the largest amount of lead immobilization, lowering the soil's absorbable lead concentration from 300 to 192 mg/kg of soil. A higher amount of anionic polymer immobilized the lead, and both cationic and non-ionic polymers were positioned after it. Additionally, anionic polymer was more prevalent than cationic polymer. It caused the non-ionic polymer's absorbable zinc to become immobile. Following 720 hours of polymer treatment, the soil's absorbable zinc element was immobilized to a greater extent by the anionic polymer (20%) than by the cationic and non-ionic polymers (26%), respectively. In comparison to the original concentration, the largest amount of immobilization by anionic polymer after one month was 78%, and the lowest amount of immobilization by nonionic polymer was 61%. Anionic polymer was 27% more effective than non-ionic polymer, 18% more effective than cationic polymer, and stabilized more cadmium. Conclusion The results of this study showed that with increasing the duration of contact of polymers used with the soil, the amount of mobility of heavy metals in the soil decreased and also with increasing the amount of polymer consumption, the rate of metal stabilization in the soil increased. Anionic polymers immobilize more lead, zinc and cadmium in soil. To reduce the mobility of lead, zinc and cadmium and improve the stability and increase aggregation in soil, the use of acrylic polymer in contaminated soil is recommended. [ABSTRACT FROM AUTHOR]

Abstract This study focuses on the synthesis of magnetite nanoparticles (MNP) coated with poly(poly(ethylene glycol) methacrylate) (PPEGMA) and/or poly(acrylic acid) (PAA) to anchor palladium nanoparticles (Pd) for their application as recyclable catalysts in the reduction of 4-nitrophenol (4NP). It was hypothesized that the abundance of oxygen atoms in PPEGMA enabled coordination with the Pd and provided good water dispersibility of the nanocomposites, while anionic PAA stabilized Pd and reduced the catalyst aggregation through electrostatic repulsion. Three different polymer coatings on MNP (PAA, PPEGMA, and PAA-co-PPEGMA polymers) were investigated to assess their influence on both the catalytic activity and reusability of the catalysts. Transmission electron microscopy (TEM) analysis indicated the distribution of spherical Pd nanoparticles (3–5 nm in diameter) and MNP (9–12 nm in diameter). Photocorrelation spectroscopy (PCS) revealed an average hydrodynamic size of the catalysts ranging from 540 to 875 nm in diameter, with a negative charge on their surface. The Pd content of the catalysts ranged from 4.30 to 6.33% w/w. The nanocomposites coated with PAA-co-PPEGMA polymers exhibited more favorable catalytic activity in the 4NP reduction than those coated with PAA or PPEGMA homopolymers. Interestingly, those containing PAA (e.g., PAA and PAA-co-PPEGMA polymers) exhibited good reusability for the 4NP reduction with a slight decrease in their catalytic performance after 26 cycles. This indicates the important role of carboxyl groups in PAA in maintaining high tolerance after multiple uses. Graphical abstract

This study focuses on the synthesis of magnetite nanoparticles (MNP) coated with poly(poly(ethylene glycol) methacrylate) (PPEGMA) and/or poly(acrylic acid) (PAA) to anchor palladium nanoparticles (Pd) for their application as recyclable catalysts in the reduction of 4-nitrophenol (4NP). It was hypothesized that the abundance of oxygen atoms in PPEGMA enabled coordination with the Pd and provided good water dispersibility of the nanocomposites, while anionic PAA stabilized Pd and reduced the catalyst aggregation through electrostatic repulsion. Three different polymer coatings on MNP (PAA, PPEGMA, and PAA-co-PPEGMA polymers) were investigated to assess their influence on both the catalytic activity and reusability of the catalysts. Transmission electron microscopy (TEM) analysis indicated the distribution of spherical Pd nanoparticles (3–5 nm in diameter) and MNP (9–12 nm in diameter). Photocorrelation spectroscopy (PCS) revealed an average hydrodynamic size of the catalysts ranging from 540 to 875 nm in diameter, with a negative charge on their surface. The Pd content of the catalysts ranged from 4.30 to 6.33% w/w. The nanocomposites coated with PAA-co-PPEGMA polymers exhibited more favorable catalytic activity in the 4NP reduction than those coated with PAA or PPEGMA homopolymers. Interestingly, those containing PAA (e.g., PAA and PAA-co-PPEGMA polymers) exhibited good reusability for the 4NP reduction with a slight decrease in their catalytic performance after 26 cycles. This indicates the important role of carboxyl groups in PAA in maintaining high tolerance after multiple uses. [ABSTRACT FROM AUTHOR]

Ketoconazole has low solubility in intestinal pH, whereas drug absorption is largest in the small intestine, which can reduce the bioavailability of the drug. Alginate can be combined with a suitable polymer and cross-linked with divalent ions and another polymer to enhance the solubility of the drug. Ketoconazole could be loaded into a matrix polymer consisting of alginate and anionic polymer through hydrogen bonds formed with the N atom of the ketoconazole. The method employed to produce ketoconazole beads involved ionic gelation with CaCl2 as a cross- linking agent, and various polymer combinations were used: alginate 100:0 (AL100), alginate:pectin 75:25 (AP75) and 50:50 (AP50), alginate:gum acacia 75:25 (AG75) and 50:50 (AG50), and alginate:carrageenan 75:25 (AK75) and 50:50 (AK50). The beads were characterized by using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), swelling study, in vitro drug release study, and solubility determination. The incorporation of ketoconazole into combination matrices of AL100, AG75, AP75, AP50, and AK75 resulted in significantly higher solubility in FaSSIF-2X (Fasted State Simulated Intestinal Fluid) at pH 6.5 compared to pure ketoconazole. [ABSTRACT FROM AUTHOR]

Cationic silica scale inhibitors are widely used, but are prone to precipitation and exhibit poor performance in geothermal systems. In this study, the cationic polymer polyethyleneimine ethoxylate (PEIE) was first found to have high silica scale inhibition efficiency. Three anionic polymers were added separately to PEIE solutions to alleviate the precipitation and scaling. The inhibition effect of PEIE alone and PEIE with anionic polymers were measured at 40°C without salt and 136.7°C with salt. Molecular dynamics simulation was used to investigate the inhibition mechanism. The results showed that PEIE exhibited good inhibition efficiency of 62% at 40°C without salt and 48% at 136.7°C with salt, while the addition of the anionic polymer acrylic acid‐2‐acrylamide‐2‐methylpropanesulfonic acid (AA/AMPS) to PEIE further improved to 71% and 62%. Compared with commercial inhibitors, the PEIE + AA/AMPS enhanced at least 15% scale inhibition efficiency. This is because the addition of AA/AMPS: (1) enhances the attraction of PEIE to silicic acid and inhibits the silicic acid condensation process; (2) chelates metal ions that promote condensation; and (3) enhances dispersion ability, stabilizing the colloid formed by PEIE and silicic acid. This study provides a promising new inhibitor and efficient strategy for inhibiting silica scale in geothermal systems. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the frequent blockages observed in the discharge pipeline in the chemical mechanical polishing wastewater treatment plant. Preliminary analyses indicated that blockages were predominantly consisted of residual organically-bounded Al due to overdosage of polyaluminum chloride (PACl) and anionic polymer during coagulation-flocculation process. To minimize the recurrence of blockage, jar test experiments were conducted in this study to identify optimum dosages of PACl and anionic polymer as well as optimum pH value. According to the model derived from jar tests, the optimum PACl dosage was dependent on the soluble Cu concentration of wastewater with low initial turbidity [ 1000 NTU), while the optimal PACl dosage was 30 mg L−1 when initial turbidity around 7000 NTU. The change of pH in the range of 8 to 9.5 did not significantly affect the turbidity or Cu removal, however, higher pH increased the deposition of residual monomeric Al species which might lead to blockage. In summary, controlling PACl dosage at optimum dosage under the conditions of pH 8.5 ± 0.5 and 1 mg L−1 polymer could reduce the blockage occurrence as well as maintain the effluent quality to meet the standards.

Locally delivered pre-exposure prophylaxis (PrEP) has proven to be a promising strategy to combat Human immunodeficiency virus (HIV) transmission but several findings encountered toxicities or proved to be marginally effective in clinical settings. Therefore, innovative, multifunctional, and safer alternatives are being progressively investigated. Herein, we explored negatively charged carbohydrate, anionic pullulan (AP) as a rapidly soluble film-former and novel anti-HIV agent. Additionally, Bictegravir (BCT), an HIV integrase inhibitor was co-delivered in the form of nanomicelles for sustained antiviral activity. BCT-loaded PLGA-PEG polymeric nanomicelles (BN) were incorporated into PVA/pullulan-based film matrix comprising of 2 % w / v AP (BN-AP film). In cell-based assays, biocompatibility and TEER values for BN-AP films were similar to control while the commercial vaginal contraceptive film (VCF®) showed severe cytotoxicity and drastically reduced the tight junction integrity. Rapid disintegration of BN-AP film with >85 % drug release was observed in simulated vaginal and seminal fluid. Most importantly, AP and BN-AP film significantly inhibited HIV-1 replication with IC 50 at as low as 91 μg/mL and 0.708 nM, respectively. Therefore, this study entails successful development of BN-AP film that functioned as an effective, biocompatible dual-acting PrEP formulation. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Cationic polymers have been widely studied for non-viral gene delivery due to their ability to bind genetic material and to interact with cellular membranes. However, their charged nature carries the risk of increased cytotoxicity and interaction with serum proteins, limiting their potential in vivo application. Therefore, hydrophilic or anionic shielding polymers are applied to counteract these effects. Herein, a series of micelle-forming and micelle-shielding polymers were synthesized via RAFT polymerization. The copolymer poly[(n-butyl acrylate)-b-(2-(dimethyl amino)ethyl acrylamide)] (P(nBA-b-DMAEAm)) was assembled into cationic micelles and different shielding polymers were applied, i.e., poly(acrylic acid) (PAA), poly(4-acryloyl morpholine) (PNAM) or P(NAM-b-AA) block copolymer. These systems were compared to a triblock terpolymer micelle comprising PAA as the middle block. The assemblies were investigated regarding their morphology, interaction with pDNA, cytotoxicity, transfection efficiency, polyplex uptake and endosomal escape. The naked cationic micelle exhibited superior transfection efficiency, but increased cytotoxicity. The addition of shielding polymers led to reduced toxicity. In particular, the triblock terpolymer micelle convinced with high cell viability and no significant loss in efficiency. The highest shielding effect was achieved by layering micelles with P(NAM-b-AA) supporting the colloidal stability at neutral zeta potential and completely restoring cell viability while maintaining moderate transfection efficiencies. The high potential of this micelle-layer-combination for gene delivery was illustrated for the first time.

This study investigated the frequent blockages observed in the discharge pipeline in the chemical mechanical polishing wastewater treatment plant. Preliminary analyses indicated that blockages were predominantly consisted of residual organically-bounded Al due to overdosage of polyaluminum chloride (PACl) and anionic polymer during coagulation-flocculation process. To minimize the recurrence of blockage, jar test experiments were conducted in this study to identify optimum dosages of PACl and anionic polymer as well as optimum pH value. According to the model derived from jar tests, the optimum PACl dosage was dependent on the soluble Cu concentration of wastewater with low initial turbidity [< 1000 nephelometry turbidity units (NTU)]. The PACl dosage would require more than 5 mg L−1 when soluble copper below 20 mg L−1, while PACl is not necessary when more than 20 mg L−1 of soluble copper in the wastewater. On the other hand, optimal PACl dosage was dependent on the initial turbidity of wastewater with high initial turbidity (> 1000 NTU), while the optimal PACl dosage was 30 mg L−1 when initial turbidity around 7000 NTU. The change of pH in the range of 8 to 9.5 did not significantly affect the turbidity or Cu removal, however, higher pH increased the deposition of residual monomeric Al species which might lead to blockage. In summary, controlling PACl dosage at optimum dosage under the conditions of pH 8.5 ± 0.5 and 1 mg L−1 polymer could reduce the blockage occurrence as well as maintain the effluent quality to meet the standards. [ABSTRACT FROM AUTHOR]

Polymers are effective products widely used in the solid-liquid separation of industrial wastes. Making solid-liquid separation in the wastes ensures that the wastes can be stored more regularly and efficiently, while removing the high water content from the landfill makes the accumulated wastes not a threat to the environment and reduces the waste volume by a significant amount, thus reducing the storage costs. Polymer performance is measured by turbidity tests. Many factors affect the effectiveness of the polymers used in solid-liquid separation, such as mixing speed, mixing time, settling time of slurry, temperature, and storage time which is the time elapsed between the use of the solid polymer after it has been prepared as a liquid solution. In this experimental study, the waste obtained from the tailings dam of the Kütahya Espey boron enrichment (concentrator) plant in its natural form, representing an industrial waste, was first dried, and then a waste ground suspension was prepared by taking the water/soil ratio in the tailings dam into account. The factors affecting the polymer performance in solid-liquid separation were determined by mixing four anionic polymers with different molecular weights into the prepared soil suspension. According to the findings, the ideal mixing speed has been determined to be 200-250 rpm, the mixing time as 1-3 minutes, and the settling time of the suspension between 2-4 minutes. Also, the suspension temperature was found to be a factor that could affect the turbidity and flocculation according to the polymer type. Moreover, the polymer solution can be used for 7 days without a decrease in its effectiveness, 24 hours after it is prepared. [ABSTRACT FROM AUTHOR]

Smart hydrogels that can respond to external stimuli such as temperature and pH have attracted tremendous interest for biological and biomedical applications. In this work, we synthesized two alginate-graft-poly(N-isopropylacrylamide) (Alg-g-PNIPAAm) copolymers and aimed to prepare smart hydrogels through formation of polyelectrolyte complex (PEC) between the negatively charged Alg-g-PNIPAAm copolymers and the positively charged chitosan (Cts) in aqueous solutions. The hydrogels were expected to be able to respond to both temperature and pH changes due to the nature of Alg-g-PNIPAAm and chitosan. The hydrogel formation was determined by a test tube inverting method and confirmed by the rheological measurements. The rheological measurements showed that the PEC hydrogels formed at room temperature could be further enhanced by increasing temperature over the lower critical solution temperature (LCST) of PNIPAAm, because PNIPAAm would change from hydrophilic to hydrophobic upon increasing temperature over its LCST, and the hydrophobic interaction between the PNIPAAm segments may act as additional physical crosslinking. The controlled release properties of the hydrogels were studied by using the organic dye rhodamine B (RB) as a model drug at different pH. The PEC hydrogels could sustain the RB release more efficiently at neutral pH. Both low pH and high pH weakened the PEC hydrogels, and resulted in less sustained release profiles. The release kinetics data were found to fit well to the Krosmyer–Peppas power law model. The analysis of the release kinetic parameters obtained by the modelling indicates that the release of RB from the PEC hydrogels followed mechanisms combining diffusion and dissolution of the hydrogels, but the release was mainly governed by diffusion with less dissolution at pH 7.4 when the PEC hydrogels were stronger and stabler than those at pH 5.0 and 10.0. Therefore, the PEC hydrogels are a kind of smart hydrogels holding great potential for drug delivery applications. [ABSTRACT FROM AUTHOR]

Cationic polymers have been widely studied for non-viral gene delivery due to their ability to bind genetic material and to interact with cellular membranes. However, their charged nature carries the risk of increased cytotoxicity and interaction with serum proteins, limiting their potential in vivo application. Therefore, hydrophilic or anionic shielding polymers are applied to counteract these effects. Herein, a series of micelle-forming and micelle-shielding polymers were synthesized via RAFT polymerization. The copolymer poly[(n-butyl acrylate)-b-(2-(dimethyl amino)ethyl acrylamide)] (P(nBA-b-DMAEAm)) was assembled into cationic micelles and different shielding polymers were applied, i.e., poly(acrylic acid) (PAA), poly(4-acryloyl morpholine) (PNAM) or P(NAM-b-AA) block copolymer. These systems were compared to a triblock terpolymer micelle comprising PAA as the middle block. The assemblies were investigated regarding their morphology, interaction with pDNA, cytotoxicity, transfection efficiency, polyplex uptake and endosomal escape. The naked cationic micelle exhibited superior transfection efficiency, but increased cytotoxicity. The addition of shielding polymers led to reduced toxicity. In particular, the triblock terpolymer micelle convinced with high cell viability and no significant loss in efficiency. The highest shielding effect was achieved by layering micelles with P(NAM-b-AA) supporting the colloidal stability at neutral zeta potential and completely restoring cell viability while maintaining moderate transfection efficiencies. The high potential of this micelle-layer-combination for gene delivery was illustrated for the first time. [ABSTRACT FROM AUTHOR]

The title compound, C25H25N9O9·C16H36N+·H2PO4− (I) or (C25H25N9O9)·(n-Bu4N+)·(H2PO4−) (systematic name: 3-(4-nitrophenyl)-1,1-bis{2-[3-(4-nitrophenyl)ureido]ethyl}urea tetrabutylammonium dihydrogen phosphate), comprises a tris-urea receptor (R), a dihydrogen phosphate anion and a tetra-n-butylammonium cation. It crystallizes with two independent formula units in the asymmetric unit. The conformations of the two tris-urea receptors are stabilized by N—H...O and C—H...O intramolecular hydrogen bonds. Each dihydrogen phosphate anion has two O—H...O intermolecular hydrogen-bonding interactions with the other dihydrogen phosphate anion. Inversion-related di-anion units are linked by further O—H...O hydrogen bonds, forming a chain propagating along the a-axis direction. Each dihydrogen phosphate anion makes a total of four N—H...O(H2PO4−) hydrogen bonds with two ureido subunits from two different tris-urea receptors, hence each tris-urea receptor provides the two ureido subunits for the encapsulation of the H2PO4− hydrogen-bonded chain. There are numerous intermolecular C—H...O hydrogen bonds present involving both receptor molecules and the tetra-n-butylammonium cations, so forming a supramolecular three-dimensional structure. One of the butyl groups and one of the nitro groups are disordered over two positions of equal occupancy.

Smart hydrogels that can respond to external stimuli such as temperature and pH have attracted tremendous interest for biological and biomedical applications. In this work, we synthesized two alginate-graft-poly(N-isopropylacrylamide) (Alg-g-PNIPAAm) copolymers and aimed to prepare smart hydrogels through formation of polyelectrolyte complex (PEC) between the negatively charged Alg-g-PNIPAAm copolymers and the positively charged chitosan (Cts) in aqueous solutions. The hydrogels were expected to be able to respond to both temperature and pH changes due to the nature of Alg-g-PNIPAAm and chitosan. The hydrogel formation was determined by a test tube inverting method and confirmed by the rheological measurements. The rheological measurements showed that the PEC hydrogels formed at room temperature could be further enhanced by increasing temperature over the lower critical solution temperature (LCST) of PNIPAAm, because PNIPAAm would change from hydrophilic to hydrophobic upon increasing temperature over its LCST, and the hydrophobic interaction between the PNIPAAm segments may act as additional physical crosslinking. The controlled release properties of the hydrogels were studied by using the organic dye rhodamine B (RB) as a model drug at different pH. The PEC hydrogels could sustain the RB release more efficiently at neutral pH. Both low pH and high pH weakened the PEC hydrogels, and resulted in less sustained release profiles. The release kinetics data were found to fit well to the Krosmyer–Peppas power law model. The analysis of the release kinetic parameters obtained by the modelling indicates that the release of RB from the PEC hydrogels followed mechanisms combining diffusion and dissolution of the hydrogels, but the release was mainly governed by diffusion with less dissolution at pH 7.4 when the PEC hydrogels were stronger and stabler than those at pH 5.0 and 10.0. Therefore, the PEC hydrogels are a kind of smart hydrogels holding great potential for drug delivery applications.

In this study, a novel anionic template polymer (TPAS) with microblock structure was prepared by ultraviolet light (UV)–assisted template copolymerization (UV-TP). Acrylamide (AM) and sodium styrene sulfonate (SSS) were selected as monomers and polypropylene ammonium chloride (PAAC) was chosen as the template. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), nuclear magnetic resonance hydrogen spectroscopy (1H NMR), and thermogravimetry/differential scanning calorimetry (TG/DSC) were used to characterize the polymer chemical structure. The results showed that the attractive anionic microblock structure was formed in TPAS. Besides, the association constant (KM) and template reaction kinetics analysis results indicated that the polymerization reaction followed I (ZIP) template copolymerization mechanism. It proved the microblock structure formation again. The anionic microblock structure in TPAM could greatly improve the ability of charge neutralization, electrical patching, and bridging. After the hematite wastewater was conditioned by TPAS with this novel anionic microblock structure, the generated hematite flocs had larger particle size and denser structure. It was favorable for the reduction of turbidity, and the turbidity removal rate could reach 97.8%. TPAS showed excellent flocculation performance for hematite wastewater and had a broad market application prospect. [ABSTRACT FROM AUTHOR]

• Anionic and cationic polymers were synthesized and the quasi-solid gels were prepared. • Dielectric properties of the quasi-solid gels were examined and they were used in DSSCs. • Cost-effective and stable DSSC fabrication was aimed with the quasi-solid gel electrolytes and poly(aniline) counter electrode. • It was observed that not only the electrical conductivity but also the wetting characteristic of gels are effective in power conversion efficiency. The use of liquid electrolytes in dye-sensitized solar cells (DSSCs) is a significant obstacle for the commercialization of DSSCs. Even the idea of evaporation or leakage of electrolyte profoundly shakes the trust in DSSCs, which are expected to last for a long time when used outdoors. At work, it aims to prepare stable and more economical DSSCs with the use of quasi-solid electrolytes and poly(aniline) (PANI) counter electrode. So, two types of quasi-solid electrolytes, anionic (AGE) and cationic gel electrolytes (CGE) were obtained after synthesized anionic poly(4-vinyl-benzenesulfonate-co-acrylic acid), and cationic poly(2-methacryloyloxyethyl trimethylammonium chloride-co- acrylic acid) hydrogel polymers engaged the liquid electrolyte. Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), frequency-dependent dielectric properties, and conductivity properties of the prepared polymers were also performed. TGA showed that both polymers were resistant to temperature-dependent degradation up to 250 °C. The prepared gels were applied onto the TiO 2 photoanode, which was sensitized by N719 dye and six DSSCs were prepared at different configurations. Current-voltage (I-V) characteristics and impedance analysis of the DSSCs were performed under 1000 W/m2 light intensity. While 6.6% and 6.3% power conversion efficiencies were obtained for the standard liquid electrolyte/Pt and liquid electrolyte/PANI cells respectively, they were in the range of 4.2–5% for DSSCs prepared with quasi-solid electrolyte/Pt-PANI counter electrodes. [ABSTRACT FROM AUTHOR]

The mixed aqueous solutions of anionic surfactant sodium dodecyl sulfate with polymer polyacrylamide of various kinds, i.e., cationic, anionic, nonionic, and zwitterion, were firstly tested to study their synergistic effect on drag reduction performance. The optimal combination of sodium dodecyl sulfate with anionic polyacrylamide was confirmed due to their strong hydrophobic interaction and electrostatic repulsion caused by the same charge. The surface tension, conductivity, and viscosity of pure surfactant solution and mixed solutions at different surfactant concentrations with anionic polymer of certain concentration were tested, and their drag reduction behavior in pipe flow was also investigated experimentally. It turns out that drag reduction performance acquired from the combination of anionic surfactant and anionic polyacrylamide is better than either of the single additive, especially under high shear rate. For the mixtures, the degree of drag reduction is strongly dependent on the concentration of SDS and more pronounced in the high Reynolds number range. The best drag reduction performance is obtained for the SDS concentration around the polymer saturation point. Our work should be of value for the drag reduction in the application such as shale gas fracturing and various fluid transports. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Vectorized small interfering RNAs (siRNAs) are widely used to induce specific mRNA degradation in the intracellular compartment of eukaryotic cells. Recently, we developed efficient cationic lipid-based siRNA vectors (siRNA lipoplexes or siLex) containing sodium alginate (Nalg-siLex) with superior efficiency and stability properties than siLex. In this study, we assessed the physicochemical and some biological properties of Nalg-siLex compared to siLex. While no significant differences in size, ζ potential and siRNA compaction were detected, the addition of sodium alginate modified the particle morphology, producing smoother and heterogeneous particles characterized by transmission electron microscopy. We also noted that Nalg-siLex have surface differences observed by X-ray photoelectron spectroscopy. These differences could arise from an internal reorganization of components induced by the addition of sodium alginate, that is indicated by Small-Angle X-ray Scattering results. Moreover, Nalg-siLex did not trigger significant hepatotoxicity nor inflammatory cytokine secretion compared to siLex. Taken together these results suggest that sodium alginate played a key role by structuring and reinforcing siRNA lipoplexes, leading to more stable and efficient delivery vector. [ABSTRACT FROM AUTHOR]

Akikazu Sakudo,1 Koichi Baba,2 Kazuyoshi Ikuta1,31Department of Virology, Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka, Japan; 2Baba Pediatric Clinic, Kadoma, Osaka, Japan; 3Kanonji Institute, The Research Foundation for Microbial Diseases of Osaka University, Kanonji, Kagawa, JapanAbstract: We recently demonstrated how various enveloped viruses can be efficiently concentrated using magnetic beads coated with an anionic polymer, poly(methyl vinyl ether-maleic anhydrate). However, the exact mechanism of interaction between the virus particles and anionic beads remains unclear. To further investigate whether these magnetic anionic beads specifically bind to the viral envelope, we examined their potential interaction with a nonenveloped virus (adenovirus). The beads were incubated with either adenovirus-infected cell culture medium or nasal aspirates from adenovirus-infected individuals and then separated from the supernatant by applying a magnetic field. After thoroughly washing the beads, adsorption of adenovirus was confirmed by a variety of techniques, including immunochromatography, polymerase chain reaction, Western blotting, and cell culture infection assays. These detection methods positively identified the hexon and penton capsid proteins of adenovirus along with the viral genome on the magnetic beads. Furthermore, various types of adenovirus including Types 5, 6, 11, 19, and 41 were captured using the magnetic bead procedure. Our bead capture method was also found to increase the sensitivity of viral detection. Adenovirus below the detectable limit for immunochromatography was efficiently concentrated using the magnetic bead procedure, allowing the virus to be successfully detected using this methodology. Moreover, these findings clearly demonstrate that a viral envelope is not required for binding to the anionic magnetic beads. Taken together, our results show that this capture procedure increases the sensitivity of detection of adenovirus and would, therefore, be a valuable tool for analyzing both clinical and experimental samples.Keywords: anionic polymer, virus concentration, adenovirus, capture, magnetic beads, poly(methyl vinyl ether-maleic anhydrate)

There is increasing interest in agro-based, biodegradable and eco-friendly wood adhesives as partial replacements for petroleum-based adhesives. In this work, we studied the adhesion of cottonseed protein isolate (CPI) blended with several anionic water-soluble polymers. Anionic vinyl polymers studied included poly(acrylate), poly(acrylate-co-acrylamide), poly(vinyl sulfate), poly(vinyl sulfonate), and poly(vinyl phosphonate). Anionic polysaccharides studied included three types of carrageenan, carboxymethyl cellulose (CMC), low-methoxy pectin, alginate, and chondroitin sulfate. In general, the adhesive strength of CPI increased with the addition of anionic polymer up to a certain level and then decreased with further polymer addition. Different anionic polymers showed different enhancements. The best result for vinyl polymers was observed for the CPI/poly(vinyl sulfate) blend, which exhibited a 30% improved dry strength over CPI alone. The best results for the polysaccharides were obtained for the CPI/CMC and CPI/pectin blends, with improvements in dry adhesive strength over the CPI control of 66% and 50%, respectively. The CPI/CMC and CPI/pectin blends also showed improved hot water resistance. These findings suggest that the CPI/anionic polymer blends might be useful components in biobased wood adhesive formulations. [ABSTRACT FROM AUTHOR]

Geosynthetic clay liners (GCLs) can be used effectively as barriers in waste containment facilities. However, interaction of the GCL with a saline solution might cause a decrease in the hydraulic performance of the GCL. In order to simulate the field conditions, triaxial permeability tests were performed on a GCL permeated with 0.5 M and 0.1 M MgCl 2 solutions at 20 °C, 40 °C and 60 °C. The temperature increase resulted in an increase in the permeability of the GCL and this increase is attributed to a decrease in the viscosity of the permeant fluid. In order to improve the hydraulic capability of the GCL, an anionic and a cationic polymer with a polymer content of 1% and 2% by mass in the bentonite-polymer mixture was added to the GCL. According to the results, polymer treatment caused up to two orders of magnitude decrease in permeability and improved the hydraulic capability of the GCL. Generally, anionic polymer treatment resulted in slightly lower permeabilities than cationic polymer treatment. Furthermore, 2% anionic polymer treatment caused almost no decrease in permittivity when compared with 1% polymer treatment. However, the permeability of 1% cationic polymer-treated GCL was the lowest among all the other anionic and cationic polymer-treated GCLs that were permeated with 0.1 MgCl 2 solution at 60 °C. [ABSTRACT FROM AUTHOR]

In this study, hydraulic conductivity and viscosity determination tests were performed on two different bentonite-granular soil mixtures having various amounts of bentonite in order to obtain the optimum mixture to be used as a liner for waste containment facilities. To enhance the hydraulic capability of these mixtures, an anionic polymer was added to the bentonite. In bentonite-granular soil mixtures, two different aggregate compositions were used: A typical aggregate composition used in the production of C20 type concrete with a void ratio of 0.33 and an aggregate composition with a void ratio of 0.21 that was the minimum void ratio determined by testing various granular soil compositions. In these two mixtures, the bentonite content varied from 8 to 15% whereas the polymer content was within the range of 0.5–10% by mass. Test results indicated that intrinsic permeability decreased drastically due to an increase in the bentonite content. 15% bentonite addition caused a decrease of almost 5.5 orders of magnitude when compared with the granular soils without any bentonite content. 2% anionic polymer addition resulted in a decrease of approximately 2.5 orders of magnitude in hydraulic conductivity. However, further increase in polymer content had almost no effect on lowering hydraulic conductivity. 2% polymer addition in bentonite-granular soil mixtures provided hydraulic conductivity values as low as 10 −11  m/s. The decrease in hydraulic conductivity was attributed to the increase in the viscosity of the fluid. Due to polymer addition, an inverse relationship existed between hydraulic conductivity and intrinsic permeability. As a result, polymer-treated bentonite-granular soil mixtures can effectively be used as barrier layers in waste containment facilities. [ABSTRACT FROM AUTHOR]

Water-based drilling fluids (WDFs) as a thermally unstable colloidal system play an essential role in the drilling operation. The filtration loss control of WDFs under high temperature and salt contamination has been a research hotspot. In this study, the copolymer (named DSA) containing different cyclic side groups was synthesized to control the filtration loss of WDFs. The chemical structure and thermal stability of the DSA were analyzed. The result showed that DSA exhibited only a slight weight loss (6.0 wt%) until 300 °C. The effect of DSA concentration on the rheological performance of WDFs was investigated with a HAAKE rheometer. The filtration loss control ability of DSA was evaluated according to the American Petroleum Institute standards. The filtration loss volume of WDFs with 15 wt% NaCl could be controlled to 9.6 ml with 2.0 wt% DSA after aging at 190 ℃. To study the mechanism, the absorption behavior of DSA on bentonite with concentration was studied. The saturated absorption capacity of 2.0 wt% DSA on bentonite was 94.7 mg/g. The effect of DSA on the dispersion of WDFs was analyzed by measuring the zeta potential and particles size distribution. Then, the micromorphology and permeability of the filter cakes for WDFs were analyzed. According to the results, DSA effectively absorbed on the bentonite surface, reducing the zeta potential and particles size of the bentonite to form filter cakes with low permeability. The filtration loss of WDFs was then controlled by DSA. The research results were instructive for the development of polymer with high temperature and salt resistance for WDFs. [Display omitted] [ABSTRACT FROM AUTHOR]

Preparation, characterization, and application of alkali starch (AS) given by dry co-grinding of starch and alkali is described in this work. Grinding using a mortar (agate) and pestle or, more conveniently, a ball mill has been found to be satisfactory for the preparation of the AS. The AS products were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and x-ray fluorescence (XRF) analyses. The base capacities of ASs were 4.25–4.45 mmol/g, respectively. AS is a low cost and easy to handle base catalyst that showed promising catalytic performance in the synthesis of a dihydroquinazoline-based antibacterial drug that involves tandem hydration or decarboxylative amidation, imination, and Aza-Michael reactions. [ABSTRACT FROM AUTHOR]

Therapeutic implementation of RNA interference (RNAi) through delivery of short interfering RNA (siRNA) is still facing several critical hurdles, which mostly can be solved through the use of an efficient delivery system. We hereby introduce anionic siRNA nanoparticles (NPs) co-assembled by the electrostatic interactions of the semi-synthetic polysaccharide hyaluronan-sulfate (HAS), with siRNA, mediated by calcium ion bridges. The NPs have an average size of 130 nm and a mild (− 10 mV) negative surface charge. Transmission electron microscopy (TEM) using gold-labeled components and X-ray photoelectron spectroscopy (XPS) demonstrated the spatial organization of siRNA molecules in the particle core, surrounded by a layer of HAS. The anionic NPs efficiently encapsulated siRNA, were stable in physiological-relevant environments and were cytocompatible, not affecting cell viability or homeostasis. Efficient cellular uptake of the anionic siRNA NPs, associated with potent gene silencing (> 80%), was observed across multiple cell types, including murine primary peritoneal macrophages and human hepatocellular carcinoma cells. In a clinically-relevant model of acute inflammatory response in IL-6-stimulated human hepatocytes, STAT3 silencing induced by HAS-Ca 2 + -siRNA NPs resulted in marked decrease in the total and activated STAT3 protein levels, as well as in the expression levels of downstream acute phase response genes. Collectively, anionic NPs prove to be an efficient and cytocompatible delivery system for siRNA. [ABSTRACT FROM AUTHOR]

Titanosilicate molecular sieve (TS-1) is an important commercial catalyst for green production of oxyfunctionalized chemicals such as alcohols, ketones, epoxides, and oximes. Active TS-1 can normally be achieved in the synthetic media strictly free of alkali metal cations (e.g., Na + and K + ). This condition severely raises the purity demands of starting reagents, which greatly increases the production cost. Herein, we developed a method to achieve highly active titanosilicates in the presence of high-concentration alkali metal cations using anionic polymer-based quasi-neutral media. This synthetic route could effectively inhibit the adverse influence of alkali metal cations on the incorporation of active titanium(IV) sites into the framework of titanosilicate, directly affording the maximal framework titanium content (2.0 wt.%) with almost 100% yield. This development shows a great commercial potential and opens the possibility of preparing silica-based molecular sieves/zeolites in non-fluoride neutral media. [ABSTRACT FROM AUTHOR]

The study explores calcium oxalate crystal inhibiting characteristic of polyacrylic acid (pAA), an anionic polymer in in vitro and in vivo . Animals were divided into 5 groups where group 1 served as control, group 2 were made hyperoxaluric by supplementing with Ethylene glycol (EG) 0.75% (v/v) for 30 days. Group 3, 4 & 5 were also given with EG and treated simultaneously with 2.5, 5 & 10 mg of pAA/kg of body weight, respectively. Urine, serum and tissue analyses along with histological studies were performed at the end of the 30 days study. In vitro crystallization was significantly inhibited by pAA and further it was supported by particle size analyses, XRD and FT-IR studies. Toxicological analyses showed that pAA was safe to use in animals at concentrations below 100 mg/kg BW. In vivo anti-urolithic study showed significant improvement in urinary lithogenic factors (calcium, oxalate, phosphate, citrate & magnesium) and renal function parameters (creatinine, urea and protein). Tissue analyses on anti-oxidant enzyme activity and lipid peroxides showed maintenance of tissue antioxidant status in the pAA supplemented rats and histological studies demonstrated the nephroprotection offered by pAA and were concurrent to the biochemical analyses. Supplementation of pAA not only reduces the crystal aggregation but also regulates the expression and localization of crystal inhibiting proteins and gene expression of inflammatory cytokines in experimental animals. In summary, pAA is a potent anti-urolithic agent in rats and we can propose that 10 mg/kg body weight is the effective dosage of pAA and this concentration can be used for further studies. [ABSTRACT FROM AUTHOR]

In this study, we developed novel siRNA transfer method to the liver by sequential intravenous injection of anionic polymer and cationic liposome/cholesterol-modified siRNA complex (cationic lipoplex). When cationic lipoplex was intravenously injected into mice, the accumulation of siRNA was mainly observed in the lungs. In contrast, when cationic lipoplex was intravenously injected at 1 min after intravenous injection of poly- l -glutamic acid (PGA) or chondroitin sulfate C (CS), siRNA was accumulated in the liver. In terms of suppression of gene expression in vivo , apolipoprotein B (ApoB) mRNA in the liver and low-density-lipoprotein (LDL) and very low-density-lipoprotein (VLDL) cholesterol level in serum were reduced at 48 h after single sequential injection of PGA or CS plus cationic lipoplex of cholesterol-modified ApoB siRNA. Furthermore, sequential injections of PGA plus cationic lipoplex of cholesterol-modified luciferase siRNA could reduce luciferase activity in tumor xenografts bearing liver metastasis of human breast tumor MCF-7-Luc. From these findings, sequential injection of anionic polymer and cationic lipoplex of siRNA might produce a systemic vector of siRNA to the liver. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate drug release mechanisms from physical mixtures of chitosan–anionic polymers-based matrix tablets and to obtain a comprehensive understanding about release characteristics. Six types of anionic polymers (i.e., Eudragit ® L100, sodium alginate, carrageenan, carboxymethylcellulose sodium, carbomer and xanthan gum) and two model drugs (i.e., theophylline and metoprolol succinate) with varied solubility were chosen. Texture analyzer, differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were applied to better understand drug release mechanisms. In vitro release experiments were conducted in a pH-changing medium to simulate the physiological condition of the gastrointestinal tract. Interestingly, a common phenomenon was observed in all the CS–anionic polymers-based matrix tablets investigated here, that is, the inner layer of the swollen tablets was coated by CS–anionic polymer polyelectrolyte complexes (PEC)-based film formed by self-assembly. Formation of the in situ self-assembled film was further confirmed by texture analysis, DSC, and FTIR. It was further identified that properties of the film were influenced by the characteristics of anionic polymers and the physiological conditions of the gastrointestinal tract. Moreover, this novel structure could alter swelling and erosion-based release mechanisms of the tablets. In addition, drug release characteristics from CS–anionic polymer systems depended on the properties of anionic polymers and the drug solubility. In conclusion, our studies may broaden current views on cationic polymer–anionic polymer-based oral matrix tablets for extended release. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the impacts of anionic polymer as a flocculant aid on the coagulation/flocculation performance with a saline solution ofMoringa oleiferaas a coagulant to provide larger flocs and decrease the time sedimentation. For the tests, raw water was used from Pirapó River Basin (Maringá, Paraná, Brazil). Optimization of coagulation/flocculation tests was initially performed in a jar-test with a dosage ofM. oleiferaLam (crude extract – MO, oil-extracted with ethanol – MO (et) and hexane – MO (hex) 1% m/v) as the coagulant that ranged from 10 to 60 mg L−1and of the anionic polymer 0.1% as a flocculant aid with a dosage that ranged from 0 to 0.4 mg L−1. The parameters analysed were colour, turbidity and compounds with absorption in UV254nm. In view of the statistical analysis results, MO (hex) with a dosage of 30 mg L−1was chosen as a coagulant for the next tests of coagulation/flocculation. When anionic polymer was used alone (0.0 mg L−1of MO (hex)), parameters were not removed and there was no generation of heavy flocs as compared with the combination of MO (hex) with the anionic polymer. Statistical analysis showed that MO (hex) obtained the highest removals of the parameters analysed in lower dosages and no significant increase in parameters removal was observed when the polymer dosage was increased. The efficacy of the coagulant+anionic polymer was optimal when 30 mg L−1of MO (hex) was used as a coagulant and 0.1 mg L−1of the anionic polymer was used as a flocculant aid, decreasing the time sedimentation from 1 h to 15 min. [ABSTRACT FROM AUTHOR]

The performance of some complex coagulants derived from weak and medium anionic polymers and medium cationic surfactant in coagulation-flocculation process for water treatment was experimentally investigated by carrying out kinetic studies and by determining the optimum coagulant dose. The complex coagulants were prepared from weak anionic and medium anionic copolymers of acrylamide and sodium acrylate with the commercial names Praestol 2515 and Praestol 2540, and medium cationic surfactant derived from triethanolamine with the commercial name Tetranyl AT-7590. The coagulation-flocculation process was studied for suspensions of kaolin particles in tap water. The electro-kinetic studies revealed that the addition of surfactant leads to a significant decrease of coagulant concentration for which the electro-kinetic potential of the dispersion medium becomes zero. The favorable influence of the addition of surfactant also resulted from the kinetic studies. Thus, the formation of some large flocks leads to shortening the flocculation period. These results are consistent with those obtained for sedimentation velocity, sludge volume and separation efficiency. [ABSTRACT FROM AUTHOR]

In this study, we developed an anionic lipoplex by coating cationic lipoplex with anionic polymers such as hyaluronan (HA), chondroitin sulfate C (CS) and poly- l-glutamic acid (PLE) to deliver the plasmid DNA efficiently into the tumor by avoiding interaction with erythrocytes. The sizes of HA-, CS- and PLE-coated lipoplexes were ∼200 nm and the ζ-potentials were negative. CS- and PLE-coated lipoplexes did not induce agglutination after mixing with erythrocytes, but cationic and HA-coated lipoplexes exhibited agglutination. In terms of biodistribution and gene expression after intravenous administration, cationic and HA-coated lipoplexes largely accumulated and induced gene expression in the lung. In contrast, CS- and PLE-coated lipoplexes did not exhibit high gene expression in the lung and mainly accumulated in the liver. However, in tumor, differences in lipoplex accumulation and gene expression were not observed among the lipoplexes. In terms of toxicity after intravenous injection, CS- and PLE-coated lipoplexes did not increase tumor necrosis factor-α, aspartate aminotransferase and alanine aminotransferase concentrations in blood. From these findings, CS and PLE coatings for cationic lipoplex might produce safe systemic vectors, although they did not increase gene expression in tumor. [ABSTRACT FROM AUTHOR]

This paper presents the physicochemical and rheological properties of some complex coagulants derived from the weak and medium anionic polymers and medium cationic surfactant in order to evaluate the opportunity to use them in destabilizing and removing the colloidal systems from water and wastewater. In this respect, weak anionic and medium anionic copolymers of acrylamide and sodium acrylate with commercial names of Preastol 2515 and Preastol 2540, and a medium cationic surfactant derived from triethanolamine with commercial name of Tetranyl AT-7590 were used in order to obtain these complex coagulants. Complex coagulants formation was revealed based on changes in physical properties of the solutions such as superficial tension and apparent viscosity. The experimental results suggest the formation mechanism of the complex by grafting of surfactant micelles on the chain of the polymer, a process that occurs in the range of surfactant concentrations ranging between its critical aggregation concentration and critical micellar concentration. Loss of viscoelastic properties of complex solutions has a beneficial effect on the interaction between colloidal particles and complex coagulant and subsequently, on the entire coagulation - flocculation process. Although complex are formed by electrostatic attraction forces they have a good mechanical strength evidenced by maintaining of the rheological characteristic at high shear rate. Therefore, it is expected that these associations to withstand the intense mechanical conditions that occur during contact of colloidal solution with complex solution. [ABSTRACT FROM AUTHOR]

Currently, the research in the field of coagulation/flocculation process is focused on the synthesis of new composite coagulants, which are constituted of both inorganic and organic materials, so as to utilize within one reagent the advantages of both inorganic and organic components. Among possible organic additives, an anionic polymer can be used by introducing it into a pre-polymerized metal (i.e. Al or Fe) coagulant. In this study, a co-polymer of acryl amide and sodium acryl ate is combined with two widely used Al or Fe based coagulants, i.e. polyaluminium chloride (PACl), and polyferric sulphate (PFS), thus producing novel composite coagulation reagents. The coagulants were characterized in terms of typical physico-chemical properties, such as the degree of polymerization, pH, conductivity, and turbidity. Finally, coagulation experiments (jar-tests) enable the comparable assessment/evaluation of coagulants efficiency, when treating model kaolin-humid acid suspensions or pre-treated tannery wastewater. [ABSTRACT FROM AUTHOR]

Abstract: A study was conducted to treat the tannery wastewater through coagulation–flocculation–sedimentation. Alum was used as coagulant with cationic and anionic polymers as coagulant aid. The results were subsequently compared with the study in which alum was used alone for the treatment. Jar test apparatus was used to conduct research work. The results of the study revealed that the combination of alum with cationic polymer C-492 [molecular weight (MW)=6 million Dalton; charge density (CD)=40%] resulted in effluent turbidity removal of 97%, total suspended solids (TSS) removal of 93.5%, total chemical oxygen demand (TCOD) removal of 36.2% and chromium removal of 98.4%. Sludge production was 40mL/L and cost of chemicals to treat one cubic meter of wastewater was $ 0.07. For this combination the optimum dose of alum was 100mg/L as Al2(SO4)3 with 5mg/L of C-496. The combination of alum with suitable anionic polymer A-100 (MW=15 million Dalton; CD=16%) resulted in effluent turbidity removal of 99.7%, TSS removal of 96.3%, TCOD removal of 48.3% and chromium removal of 99.7%. Sludge production was 30mL/L and cost of chemicals to treat one cubic meter of wastewater was $ 0.08. The results of the above combinations were compared with those when alum was used alone for the treatment. The comparison revealed that use of coagulant aid reduced sludge volume by 60–70% and cost of chemicals by 50% for comparable removal efficiencies. [Copyright &y& Elsevier]

Abstract: Respiratory syncytial virus (RSV) is the single most important cause of severe lower respiratory tract infections in infants and young children, and a major public health concern in pediatrics. However, current diagnostic methods for RSV are not sufficiently sensitive. In addition, there is no simple method for enhancing RSV detection. Here, a method for capturing RSV from nasal fluid has been developed using magnetic beads coated with an anionic polymer, poly(methyl vinyl ether-maleic anhydrate). The beads were incubated with RSV-infected nasal fluid, then separated from the supernatant by applying a magnet field and washed. The absorption of RSV by the beads was confirmed by immunochromatography, reverse transcription-polymerase chain reaction, Western blotting and an enzyme-linked immunosorbent assay, which indicated the presence of nucleocapsid protein, fusion protein, and the viral genome of RSV on the incubated beads. Therefore, this capture method will contribute to the improvement of RSV detection. [Copyright &y& Elsevier]