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It is urgently demanded to develop biomaterials with balanced hemostatic/antibacterial ability and facile preparation methods. In this work, cationic starch microparticles (MSQP), prepared by the facile grafting of microporous starch particles (MS) with tunable quaternized polyethyleneimine, were readily constructed as promising hemostatic materials for integrated antibacterial and hemostatic performance. The cationic grafts not only endowed MSQP with good antibacterial ability, but also benefited from biocompatible MS to achieve favorable biocompatibility. Moreover, in vitro results confirmed the superior hemostatic property of MSQP2 (with the medium content of cationic grafts) among three MSQP and pristine MS. After investigating the blood-material interactions of MSQP/MS, the procoagulant mechanism of MSQP2 was revealed that the optimal amount of cationic grafts achieves highly balanced plasma-protein adhesion, platelet adhesion and blood coagulation system. In vivo artery-injury model further demonstrated the superior hemostatic performance of MSQP2 for potential severe hemorrhage. This work sheds light on the design of cationic polymer-based biomaterials for balanced antibacterial and hemostatic functions. [ABSTRACT FROM AUTHOR]

Abstract Background The therapeutic resistance to ionizing radiation (IR) and angiogenesis inhibitors is a great challenge for clinicians in the treatment of glioblastoma, which is associated with Hepatocyte growth factor (HGF)/MET, VEGF/VEGFR signaling pathway, and the crosstalk between them. In this study, we developed a novel recombinant fusion protein, rE27HGFK1, via HGFK1 tandem with 27 N-terminal residues of Endostatin (E27) and produced a polymeric nanoparticle formed by the co-polymer of PEGylated H1 cationic polymer (PH1) with a plasmid encoding the secreted rE27HGFK1 protein (PH1/pE27HGFK1). We further investigated the anti-tumor effects of rE27HGFK1 and PH1/pE27HGFK1 nanoparticles both in vivo and in vitro. Methods We expressed and purified the rE27HGFK1 protein via E. coli. Then, we performed cellular experiments to determine the antitumoral effects and IR radio-sensitivities of the rE27HGFK1 protein in vitro. Finally, we performed animal studies to determine the tumor-targeted abilities and antitumoral activities of the polymeric nanoparticles, PH1/pE27HGFK1, in an orthotopic U118-Luc-bearing xenografted mouse model. Results We showed that rE27HGFK1 inhibited the proliferation and the angiogenesis and enhanced the senescence and radiosensitivity of GBM via both MET and VEFGR2 signaling mediated-p16 over-expression and the down-regulation of cyclin D1-CDK4-Rb axis activities in vitro. Next, we displayed that systemic administration of the PEGylated H1 cationic polymer (PH1) effectively delivered the reporter genes to the brain tumor of an orthotopic U118-bearing xenografted mouse model. Finally, we showed that PH1/pE27HGFK1 significantly produced antitumor effects with radiosensitivity in the orthotopic U118-Luc-bearing xenografted Blab/c mouse model through inhibiting angiogenesis and tumor cell proliferation, as well as inducing the necrosis of tumor cells in vivo. Conclusions The PH1/pE27HGFK1 nano-drug combined with radiotherapy can be used as a potentially effective therapeutic strategy for Glioblastoma multiforme.

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.

Using cheap epichlorohydrin and dimethylamine as monomers in order to introduce cationic groups, acrylamide as another monomer, and ammonium persulfate as initiator through free radical copolymerization in aqueous solution, cationic sacrifice agent (SA1) was synthesized. Similarly, an amphoteric sacrifice agent (SA2) containing both quaternary amine and carboxylate functional group was synthesized. The terpolymers were used as a sacrifice material for polycarboxylate superplasticizer (PCE), and its reactive mechanism in cement–PCE–water with clay system was studied, which is desirable to solve the problem of PCE sensitivity to clay. The flow behavior of cement paste containing PCE in the presence and absence of clay was assessed. It was pointed out that the presence of montmorillonite (MMT) or kaolin significantly reduced the dispersion effect of PCE, eventually decreased the slurry fluidity. Fortunately, the addition of the sacrifice agents hindered this disadvantage. The fluidity of slurry increased with the increase in the amount compared with the lack of sacrificial agent. The sacrifice agent has a positive effect on retaining the fluidity of cement pastes, and to some extent makes up for the poor dispersion of PCE in the presence of clay impurities. The adsorption of SA1 or SA2 by MMT particles was studied by total organic carbon (TOC) analyzer. The results show that SA1 or SA2 can be preferentially adsorbed on particles by MMT compared with conventional PCE which result in more releasing PCE macromolecules and less useless loss. The sacrifice agent provides a possibility for improving the adaptability of PCE in low-quality cementing materials and has a potential application. [ABSTRACT FROM AUTHOR]

Background: The therapeutic resistance to ionizing radiation (IR) and angiogenesis inhibitors is a great challenge for clinicians in the treatment of glioblastoma, which is associated with Hepatocyte growth factor (HGF)/MET, VEGF/VEGFR signaling pathway, and the crosstalk between them. In this study, we developed a novel recombinant fusion protein, rE27HGFK1, via HGFK1 tandem with 27 N-terminal residues of Endostatin (E27) and produced a polymeric nanoparticle formed by the co-polymer of PEGylated H1 cationic polymer (PH1) with a plasmid encoding the secreted rE27HGFK1 protein (PH1/pE27HGFK1). We further investigated the anti-tumor effects of rE27HGFK1 and PH1/pE27HGFK1 nanoparticles both in vivo and in vitro. Methods: We expressed and purified the rE27HGFK1 protein via E. coli. Then, we performed cellular experiments to determine the antitumoral effects and IR radio-sensitivities of the rE27HGFK1 protein in vitro. Finally, we performed animal studies to determine the tumor-targeted abilities and antitumoral activities of the polymeric nanoparticles, PH1/pE27HGFK1, in an orthotopic U118-Luc-bearing xenografted mouse model. Results: We showed that rE27HGFK1 inhibited the proliferation and the angiogenesis and enhanced the senescence and radiosensitivity of GBM via both MET and VEFGR2 signaling mediated-p16 over-expression and the down-regulation of cyclin D1-CDK4-Rb axis activities in vitro. Next, we displayed that systemic administration of the PEGylated H1 cationic polymer (PH1) effectively delivered the reporter genes to the brain tumor of an orthotopic U118-bearing xenografted mouse model. Finally, we showed that PH1/pE27HGFK1 significantly produced antitumor effects with radiosensitivity in the orthotopic U118-Luc-bearing xenografted Blab/c mouse model through inhibiting angiogenesis and tumor cell proliferation, as well as inducing the necrosis of tumor cells in vivo. Conclusions: The PH1/pE27HGFK1 nano-drug combined with radiotherapy can be used as a potentially effective therapeutic strategy for Glioblastoma multiforme. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is one of the most refractory organisms to antibiotic treatment and appears to be one of the least susceptible to photodynamic treatment. TMPyP is effective in the photoinactivation of P. aeruginosa, and the co‐administration with the cationic polymer Eudragit®‐E100 (Eu) potentiates this effect against isolates both sensitive and resistant to antibiotics. The fluorescent population (>98%) observed by flow cytometry after exposure to Eu + TMPyP remained unchanged after successive washings, indicating a stronger interaction/internalization of TMPyP in the bacteria, which could be attributed to the rapid neutralization of surface charges. TMPyP and Eu produced depolarization of the cytoplasmic membrane, which increased when both cationic compounds were combined. Using confocal laser scanning microscopy, heterogeneously distributed fluorescent areas were observed after TMPyP exposure, while homogeneous fluorescence and enhanced intensity were observed with Eu + TMPyP. The polymer caused alterations in the bacterial envelopes that contributed to a deeper and more homogeneous interaction/internalization of TMPyP, leading to a higher probability of damage by cytotoxic ROS and explaining the enhanced result of photodynamic inactivation. Therefore, Eu acts as an adjuvant without being by itself capable of eradicating this pathogen. Moreover, compared with other therapies, this combinatorial strategy with a polymer approved for pharmaceutical applications presents advantages in terms of toxicity risks. [ABSTRACT FROM AUTHOR]

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 Infection control measures to prevent viral and bacterial infection spread are critical to maintaining a healthy environment. Pathogens such as viruses and pyogenic bacteria can cause infectious complications. Viruses such as SARS-CoV-2 are known to spread through the aerosol route and on fomite surfaces, lasting for a prolonged time in the environment. Developing technologies to mitigate the spread of pathogens through airborne routes and on surfaces is critical, especially for patients at high risk for infectious complications. Multifunctional coatings with a broad capacity to bind pathogens that result in inactivation can disrupt infectious spread through aerosol and inanimate surface spread. This study uses C-POLAR, a proprietary cationic, polyamine, organic polymer with a charged, dielectric property coated onto air filtration material and textiles. Using both SARS-CoV-2 live viral particles and bovine coronavirus models, C-POLAR-treated material shows a dramatic 2-log reduction in circulating viral inoculum. This reduction is consistent in a static room model, indicating simple airflow through a static C-POLAR hanging can capture significant airborne particles. Finally, Gram-positive and Gram-negative bacteria are applied to C-POLAR textiles using a viability indicator to demonstrate eradication on fomite surfaces. These data suggest that a cationic polymer surface can capture and eradicate human pathogens, potentially interrupting the infectious spread for a more resilient environment.IMPORTANCEInfection control is critical for maintaining a healthy home, work, and hospital environment. We test a cationic polymer capable of capturing and eradicating viral and bacterial pathogens by applying the polymer to the air filtration material and textiles. The data suggest that the simple addition of cationic material can result in the improvement of an infectious resilient environment against viral and bacterial pathogens.

Polyquaternium polymers are widely used in various applications, such as personal care products and wastewater treatment plants, and eventually end up in the aquatic environment. While polymers have been perceived of low toxicological concern due to their size, several studies have pointed towards water-soluble cationic polymers being toxic towards aquatic organisms – and that the toxicity largely is determined by the polymer charge density. The present study investigated the polyquaternium toxicological mechanism of action throughout lipidomic analysis and changes in immune-gene expression (qPCR) of zebrafish larvae exposed continuously to two water-soluble polymers; a high charge density polyquaternium-6 and a low charge density polyquaternium-10, for 5 and 12 days upon fertilization. The results showed that the investigated polyquaterniums cause both inflammatory responses and significant alterations of the zebrafish larvae lipidome. Depending on polyquaternium polymer and larvae development stage, the gene expression showed an inflammatory response (e.g. significant up-regulation of il8, il1β and tnfα) in the exposed zebrafish. Alterations of the lipidome were additionally observed, with severe depletion of lipids (e.g. lyso-glycerophosphocholines and ceramides) in the 12 days old larvae exposed to high charge density polymer. The findings furthermore support a hypothetical mechanism of action to be non-specific and lethality potentially to be narcosis-like driven.

Antibacterial coatings are becoming increasingly attractive for application in the field of biomaterials. In this framework, we developed polymer coating zirconia with antibacterial activity using the "grafting from" methodology. First, 1-(4-vinylbenzyl)-3-butylimidazolium chloride monomer was synthesized. Then, the surface modification of zirconia substrates was performed with this monomer via surface-initiated photo atom transfer radical polymerization for antibacterial activity. X-ray photoelectron spectroscopy, ellipsometry, static contact angle measurements, and an atomic force microscope were used to characterize the films for each step of the surface modification. The results revealed that cationic polymers could be successfully deposited on the zirconia surfaces, and the thickness of the grafted layer steadily increased with polymerization time. Finally, the antibacterial adhesion test was used to evaluate the antibacterial activity of the modified zirconia substrates, and we successfully showed the antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains. [ABSTRACT FROM AUTHOR]

Smart nanomedicinal treatment for cancer manifests a solubility challenge with inherent nanoscale size and nonspecific release with stimuli-responsive potential. This is the limelight in novel chemotherapy to pursue physiochemical differences between the tumor microenvironment (TME) and normal cells, which introduces active groups of nanocarriers responding to various stimuli, endowing them with concise responses to various tumor-related signals. The nanogels were successfully prepared by a modified solvent evaporation technique. Nine batches were formulated by changing the chitosan concentration (12, 14, 16 mg/ml) and sonication time (5, 10, 15 min). The formulations were optimized for particle size and zeta potential with high percent entrapment efficiency (%EE) through Central Composite Design software. The optimized batch F7 had a 182-nm size and high zeta potential (64.5 mV) with 98% EE. The drug release of F7 was higher at pH 6 (97.556%) than at pH 7.4 (45.113%). The pharmacokinetic study shows that the release follows the Hixon plot model (R2 = 0.9334) that shifts to zero order (R2 = 0.9149). The nanogel F7 was observed for stability and showed an absence of color change, phase separation, and opacity for 6 months. In the present study, the pH difference between cancer cells and normal cells is the key point of the smart nanogel. This study is promising but challenging depending on the in vivo study. The nanogel was successfully prepared and evaluated for pH-responsive release. As hemangiosarcoma commonly occurs in dogs, this formulation helps to limit the difficulties with administration. [ABSTRACT FROM AUTHOR]

The cationic polymer plays a crucial role in the flocculation process for solid–liquid separation. A hydrophobic‐associated cationic polymer was prepared through micellar free‐radical polymerization of cationic monomer 3‐methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC) and hydrophobic monomer Poly (ethylene glycol) Octadecyl methacrylate (OEMA). The Poly‐MAPTAC‐OEMA can form network structure through intermolecular hydrophobic association in aqueous solution, which leads to the solution viscosity increase and the salt thickening property. The critical associating concentrations (CACs) of Poly‐MAPTAC‐OEMA are 5818–6992 mg/L in aqueous solution. For the diatomite suspensions, at the dosage above about 5 mg/L, the Poly‐MAPTAC‐OEMA can show higher flocculation efficiency compared with Poly‐MAPTAC. Specifically, at the dosage of 8 mg/L, the enhancement rate of sedimentation rate can reach 7.27%–32.31%. Meanwhile, the hydrophobic association mainly enhances the bridging ability but has no significant effect on the improvement of the electric neutralization ability of Poly‐MAPTAC‐OEMA. The flocculation performance‐enhanced dosage of Poly‐MAPTAC‐OEMA is obviously lower than the CAC of Poly‐MAPTAC‐OEMA; this may be because during the flocculation process, the Poly‐MAPTAC‐OEMA first absorb and deeply concentrate on the particle surface, and then the hydrophobic association and bridging enhancement of Poly‐MAPTAC‐OEMA can occur more easily on the particle surface. [ABSTRACT FROM AUTHOR]

The use of aluminium (Al) salts, particularly alum, in coagulation is a widespread and conventional treatment method for eliminating pollutants, including phosphorus (P) which can cause eutrophication, from wastewater. However, a significant challenge of this process is the substantial amount of sludge generated, necessitating proper disposal. Historically, land disposal has been a common practice, but it poses potential issues for plant life on these lands. Despite the associated drawbacks, sludge contains elevated concentrations of vital plant nutrients like P and nitrogen, presenting an opportunity for beneficial use in agriculture. Given the imminent scarcity of P fertilizers due to the eventual depletion of high-grade P ores, this review explores the potential advantages and challenges of utilizing Al sludge as a P source for plants and proposes measures for its beneficial application. One primary concern with land application of Al sludge is its high levels of soluble Al, known to be toxic to plants, particularly in acidic soils. Another issue arises from the elevated Al concentration is P fixation and subsequently reducing P uptake by plants. To address these issues, soil treatment options such as lime, gypsum, and organic matter can be employed. Additionally, modifying the coagulation process by substituting part of the Al salts with cationic organic polymers proves effective in reducing the Al content of the sludge. The gradual release of P from sludge into the soil over time proves beneficial for plants with extended growth periods. [ABSTRACT FROM AUTHOR]

Applications of haloalkane dehalogenase DhaA in biocatalysis are limited by its unfavorable performance in organic solvents. Our previous work proved that mutations of surface positive-charged residues enhanced the organic solvent resistance of DhaA, which inspired us to explore the effect of cationic polymers on DhaA in organic solvents. Remarkably boosted performance was achieved in different organic solvent solutions by introducing cationic polymers, for example, there was a 6.1-fold activity increase with poly(allylamine hydrochloride) and a 5.5-fold activity increase with poly(ethylene imine) in 40 vol.% dimethylsulfoxide. The presence of cationic polymers protected DhaA from damage by organic solvents and increased the substrate concentration around the enzyme-polymer complex. Fluorescence spectroscopy and molecular dynamics simulations revealed that the binding of cationic polymers onto DhaA weakened the interactions between organic solvents and DhaA, decreased the organic solvent solvation level around DhaA, and enhanced the structural stability of DhaA in organic solvents. This comprehensive understanding of the effect of cationic polymers on DhaA can help to broaden the applications of DhaA in organic solvent-involved biocatalysis. [ABSTRACT FROM AUTHOR]

Polyethlyenimine (PEI) was introduced 1995 as a cationic polymer for nucleic acid delivery. PEI and its derivatives are extensively used in basic research and as reference formulations in the field of polymer-based gene delivery. Despite its widespread use, the number of clinical applications to date is limited. Thus, this review aims to consolidate the past applications of PEI in DNA delivery, elucidate the obstacles that hinder its transition to clinical use, and highlight potential prospects for novel iterations of PEI derivatives. The present review article is divided into three sections. The first section examines the mechanism of action employed by PEI, examining fundamental aspects of cellular delivery including uptake mechanisms, release from endosomes, and transport into the cell nucleus, along with potential strategies for enhancing these delivery phases. Moreover, an in-depth analysis is conducted concerning the mechanism underlying cellular toxicity, accompanied with approaches to overcome this major challenge. The second part is devoted to the in vivo performance of PEI and its application in various therapeutic indications. While systemic administration has proven to be challenging, alternative localized delivery routes hold promise, such as treatment of solid tumors, application as a vaccine, or serving as a therapeutic agent for pulmonary delivery. In the last section, the outcome of completed and ongoing clinical trials is summarized. Finally, an expert opinion is provided on the potential of PEI and its future applications. PEI-based formulations for nucleic acid delivery have a promising potential, it will be an important task for the years to come to introduce innovations that address PEI-associated shortcomings by introducing well-designed PEI formulations in combination with an appropriate route of administration. [Display omitted] • PEI was introduced 1985 as a cationic polymer for nucleic delivery. • PEI-based research has provided a wealth of pre-clinical data. • Challenges associated with the use of PEI are analyzed. • A comprehensive analysis of clinical trials is provided. • New generations of PEI-derivatives offer interesting options. [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]

Background: Hearing loss is a condition that may affect a wide array of patients from various backgrounds. There are no cures for sensorineural hearing loss. Gene therapy is one possible method of improving hearing status; however, gene delivery remains challenging. Materials & methods: Polymer nanoaggregates of alginate and poly-L-lysine were prepared with and without bile acid. The nanoaggregates had physical properties, cytotoxicity, gene release and gene expression analyzed. Results & discussion: The nanoparticles produced had appropriate size and charge, low cytotoxicity between 0.5 and 1.0 mg/ml and linear gene release but poor transfection efficiency. Conclusion: The present study provides preliminary evidence for the efficacy of polymer nanotechnology with bile acids for inner ear gene delivery; optimization is required to improve transfection efficiency. Hearing loss is a global issue with significant consequences. Gene therapy is an emerging technique in the management of various conditions, including hearing loss. This involves the delivery of a new copy of a gene to a cell with a missing or defective copy of that gene. The delivery of genes such as ATOH1 has been shown to encourage cell differentiation into new functional hair cells to potentially reverse hearing loss. Unfortunately, effective and safe delivery of genes remains challenging. Polymer nanoparticles represent one method for delivering genes that allows for customizability in size, structure and function. In this study, the authors developed nanoparticles with a polymer derived from algae called alginate, an amino acid polymer called poly-L-lysine and bile acid to improve gene delivery to inner ear cells. A cell line derived from the inner ear of a mouse was used to test the effectiveness of these particles at delivering genes. A gene that makes cells that uptake these particles fluoresce was included in the nanoparticles, to demonstrate they are capable of gene delivery. In the future, this gene could be replaced with genes associated with encouraging cell differentiation. The preliminary results of this study suggest that such nanoparticles may be capable of gene delivery, although further optimization is required. [ABSTRACT FROM AUTHOR]

Nucleic acids can modulate gene expression specifically. They are increasingly being utilized and show huge potential for the prevention or treatment of various diseases. However, the clinical translation of nucleic acids faces many challenges due to their rapid clearance after administration, low stability in physiological fluids and limited cellular uptake, which is associated with an inability to reach the intracellular target site and poor efficacy. For many years, tremendous efforts have been made to design appropriate delivery systems that enable the safe and effective delivery of nucleic acids at the target site to achieve high therapeutic outcomes. Among the different delivery platforms investigated, polymeric micelles have emerged as suitable delivery vehicles due to the versatility of their structures and the possibility to tailor their composition for overcoming extracellular and intracellular barriers, thus enhancing therapeutic efficacy. Many strategies, such as the addition of stimuli-sensitive groups or specific ligands, can be used to facilitate the delivery of various nucleic acids and improve targeting and accumulation at the site of action while protecting nucleic acids from degradation and promoting their cellular uptake. Furthermore, polymeric micelles can be used to deliver both chemotherapeutic drugs and nucleic acid therapeutics simultaneously to achieve synergistic combination treatment. This review focuses on the design approaches and current developments in polymeric micelles for the delivery of nucleic acids. The different preparation methods and characteristic features of polymeric micelles are covered. The current state of the art of polymeric micelles as carriers for nucleic acids is discussed while highlighting the delivery challenges of nucleic acids and how to overcome them and how to improve the safety and efficacy of nucleic acids after local or systemic administration. [ABSTRACT FROM AUTHOR]

Introduction: Periodontal ligament is regenerated in association with hard tissue regeneration. Tenomodulin (Tnmd) expression has been confirmed in periodontal ligament and it reportedly inhibits angiogenesis or is involved in collagen fibril maturation. The introduction of Tnmd by gene transfection in bone tissue regeneration therapy might inhibit topical hard tissue formation and induce the formation of dense fibrous tissue. Therefore, the effect of Tnmd introduction by gene transfection technique in vitro and in vivo was investigated in this study. Methods: Osteogenesis- and chondrogenesis-related gene expression levels in osteoblastic cells (MC3T3E1) and rat bone marrow derived cells were detected using qPCR three days after gene transfection with plasmid DNA (Tnmd) using non-viral gene transfection vectors: a calcium phosphate-based gene transfection vector (CaP(Tnmd)) or a cationic polymer-based reagent (JetPEI (Tnmd)). Next, an atelocollagen scaffold with or without CaP (Tnmd) or JetPEI (Tnmd) was implanted into a rat calvaria bone defect, and the remaining bone defect volume and the tissue reaction at 28 days after surgery were evaluated. Results: Runx 2 and SP7 mRNA was reduced by JetPEI (Tnmd) in both cells, but not in CaP(Tnmd). The volume of expressed Tnmd was at 9 ng/mL in both gene transfection vector. The remaining bone defect volume of JetPEI (Tnmd) was significantly bigger than that of the other groups and CaP (EGFP), and that of CaP (Tnmd) was significantly bigger than that of CaP (EGFP). Conclusions: Tnmd introduction treatment inhibits bone formation in artificial bone defect, however, the effect of that was dependent on non-viral gene transfection vector.

Antibacterial coatings are becoming increasingly attractive for application in the field of biomaterials. In this framework, we developed polymer coating zirconia with antibacterial activity using the “grafting from” methodology. First, 1-(4-vinylbenzyl)-3-butylimidazolium chloride monomer was synthesized. Then, the surface modification of zirconia substrates was performed with this monomer via surface-initiated photo atom transfer radical polymerization for antibacterial activity. X-ray photoelectron spectroscopy, ellipsometry, static contact angle measurements, and an atomic force microscope were used to characterize the films for each step of the surface modification. The results revealed that cationic polymers could be successfully deposited on the zirconia surfaces, and the thickness of the grafted layer steadily increased with polymerization time. Finally, the antibacterial adhesion test was used to evaluate the antibacterial activity of the modified zirconia substrates, and we successfully showed the antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa strains.

One of the important goals of cancer treatment in drug delivery systems (DSS) is to increase the concentration of the drug only around the tumor cells to prevent damage to normal cells. In this study, doxorubicin (DOX) was imprinted by the cationic polymer; Poly (methacrylic acid-co-diallyldimethylammonium chloride) PMA DDA coated-GQDs. Chemical structure PMA DDA-coated GQDs was investigated and confirmed by using Fourier-transform infrared spectroscopy (FT-IR). Particle size and morphology of PMA DDA-coated GQDs was evaluated by Field Emission Scanning Electron Microscope (FE-SEM). Then the toxicity of PMA DDA-coated GQDs was investigated in vitro study. Also to evaluate the effectiveness of PMA DDA-coated GQDs in the living organism, Nanoparticles were injected into BALB/C mice containing 4T1 breast cancer cells. Then in vivo imaging was performed at the excitation wavelength of 400 nm and emission of 535 nm. The images showed that particles PMA DDA-coated GQDs had accumulated around the cancer cell. [ABSTRACT FROM AUTHOR]

Synthetic water-soluble polymers, such as acrylamide-based compounds, i.e., partially hydrolyzed polyacrylamide (HPAM), are well known for polymer flooding in enhanced oil recovery (EOR) and drilling fluid supplement for well-drilling operations. However, these types of polymers have low thermal stability and mechanical resistance. Therefore, it was decided to synthesize a polymer according to the petroleum reservoir harsh conditions by selecting appropriate monomers that are stable to salinity, temperature, shear stress and to improve their properties with nanoparticles. Hence, simultaneous usage of polymer and nanomaterials in the resulting nanocomposite is expected to overcome their remaining deficiencies. In this research, a copolymer (NVP-co-APTAC) was prepared from comprising of 3-acrylamidopropyl trimethylammonium chloride (APTAC) as cationic monomer and N-vinylpyrrolidone (NVP) monomer with constant molar ratio (0.3:0.7) through aqueous media, by free-radical polymerization method. Nano-alumina particles (Al2O3), with different values at 0.05, 0.1, 0.15 and 0.2 wt% relative to the total weight of monomers were added to produce the nanocomposite (NVP-co-APTAC/Al2O3). The chemical structure of synthesized nanocomposite was characterized by conventional techniques. The results have shown that the nanocomposite containing 0.2 wt% of nano-alumina with respect to total monomers weight has high rheological behavior. [ABSTRACT FROM AUTHOR]

Influence of cationic polymer (KN) on the floccule size of cement pastes containing plycarboxylate superplasticizer (PCE) and Na-bentonite was studied. The proportion of floccule size and grain size d f / d g was obtained from a rheological analysis with the application of Herschel–Bulkley model and modified Krieger–Dougherty model. Herschel–Bulkley model was used to gain the yield stress according to our previous study. Cement pastes were investigated both at the beginning and after one hour. The results showed that a high value of d f / d g was noticed under low shear rate range and then the proportion decreased with the increase of shear rate. For cement paste containing PCE and Na-bentonite in the absence of KN, larger floccule was formed due to the intercalation of polyethylene glycol branch chain of PCE into the interlayer space of Na-bentonite. However, the floccule size of cement pastes obviously decreased with the increasing addition amount of KN. Thus, KN will restrain the formation of floccules in cement pastes containing PCE and Na-bentonite to a certain extent. [ABSTRACT FROM AUTHOR]

Polymer‐contained oily sludge is inevitably produced when the oily wastewater produced from polymer flooding (OWPF) is treated by a cationic polymer clarifier, and it severely affects oilfield production. This study designed a novel degradable cationic clarifier (DCC) based on the ester bond and prepared it in light of the poly(β‐amino ester) used in the area of generic material delivery. First, the copolymer of N‐[3‐(dimethylamino) propyl] methacryamide (DMAPMA) and diallylamine (PDMAPMA‐NH) were synthesized by radical copolymerization. Then, the DCC was prepared by Michael addition between PDMAPMA‐NH and poly(ethylene glycol) diacrylate. The synthesis conditions of DCC were investigated, and a DCC with excellent flocculant performance and good degradability was successfully prepared. At 70°C, both the degradations of DCC and the water‐insoluble polymer complex formed by DCC and the polymer used for polymer flooding can be completed in 10 h, which is beneficial for the self‐disappearance of the polymer‐contained oily sludge. The flocs formed by DCC were observed at different times, and the results confirmed that the flocs can change to an oil film and that the polymer‐contained oily sludge cannot exist for a long time. This study provides inspiration for OWPF treatment and expands the new application for poly(β‐amino ester). [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance attributed to the overuse and abuse of antibiotics severely endangers global biosafety. Antimicrobial peptides (AMPs) produced by various living organisms exhibit broad-spectrum antimicrobial properties with a low propensity to the resistance. However, the application of AMPs has been greatly limited owing to their poor stability, high manufacturing cost, and high cytotoxicity. Thus, AMP-mimetic antimicrobial cationic polymers with cationic and amphiphilic moieties have attracted considerable attention as antimicrobial agents. These polymers typically exhibit broad-spectrum antimicrobial activities, negligible antimicrobial resistance, and rapid bactericidal effect. These polymers exhibit low hemolysis and cytotoxicity by optimizing their chemical structures. In this study, we summarize the design principles and current findings of antimicrobial cationic polymers and identify potential candidates for developing innovative polymeric antimicrobials.

Since nanoparticles are taken up into cells by endocytosis, phagocytosis, or pinocytosis, they have been studied as intracellular drug carriers. Janus particles have an anisotropic structure composed of two or more distinct domains and have been proposed for use in various applications, including use as imaging agents or nanosensors. This study aimed to clarify the influence of the type of nanoparticles on their distribution in a human Caucasian colon adenocarcinoma (Caco-2) cell monolayer. We fabricated Janus and conventional spherical nanoparticles composed of pharmaceutically applicable ingredients. Janus and spherical nanoparticles composed of a cationic polymer and surfactant lipids were prepared by controlling the solvent removal pattern from the oil phase in the solvent removal process using the solvent evaporation and solvent diffusion methods. The distribution of nanoparticles in the Caco-2 cell monolayer was then evaluated using confocal laser microscopy. The mean hydrodynamic size of the fabricated Janus nanoparticles was 119.2 ± 4.6 nm. Distribution analysis using Caco-2 cells suggested that Janus nanoparticles were localized around the adherens junctions located just below the tight junction. Clear localization was not observed in non-Janus nanoparticles with the same composition. The clear localization of the Janus nanoparticles around the adherens junction may be due to their positive charge and asymmetric structure. Our results suggest the considerable potential for the development of nanoparticulate drug carriers to target cellular gaps. [ABSTRACT FROM AUTHOR]

Prion diseases, also known as transmissible spongiform encephalopathies, are caused by the accumulation of abnormal isoforms of the prion protein (scrapie isoform of the prion protein, PrPSc) in the central nervous system. Many compounds with anti-prion activities have been found using in silico screening, in vitro models, persistently prion-infected cell models, and prion-infected rodent models. Some of these compounds include several types of polymers. Although the inhibition or removal of PrPSc production is the main target of therapy, the unique features of prions, namely protein aggregation and assembly accompanied by steric structural transformation, may require different strategies for the development of anti-prion drugs than those for conventional therapeutics targeting enzyme inhibition, agonist ligands, or modulation of signaling. In this paper, we first overview the history of the application of polymers to prion disease research. Next, we describe the characteristics of each type of polymer with anti-prion activity. Finally, we discuss the common features of these polymers. Although drug delivery of these polymers to the brain is a challenge, they are useful not only as leads for therapeutic drugs but also as tools to explore the structure of PrPSc and are indispensable for prion disease research. [ABSTRACT FROM AUTHOR]

Acrylamide, 30% acrylamide/methyl-diacrylamide (29:1), methylacryloxyethyl trimethylammonium chloride, hexadecyl-octadecyl dimethylallyl ammonium chloride were the main synthetic monomers. The polymerization initiator was water soluble 2,2-azo (2-methylpropamidine) dihydrochloride, and the hydrophobic association cationic polymer thickener (PASM) was synthesized. Structural characterization and performance test of the products were carried out. The results show that the critical association concentration of the thickener PASM is 0.5%,the molecular weight is 417.3×104, the resistance to Na+ and Ca2+ is strong, and with the increase of salinity, the initial viscosity of the system shows an increasing trend, showing excellent thickening performance. Under the condition of low concentration, high anti-swelling effect can be achieved, and the suspended sand performance is excellent. There is no residue after ammonium sulfate breaking, and the breaking liquid will not cause secondary damage to the formation, so it has a broad prospect of industrialization [ABSTRACT FROM AUTHOR]

Chitosan, a cationic polymer, is loaded on Ni-doped copper monosulfide (CuS) NPs with optimal Ni doping concentration, and electrochemical, third-order nonlinear, magnetic and antibacterial characteristics of chitosan unloaded and loaded CuS:Ni nanoparticles are compared. The crystallite size of pure CuS increased with Ni doping and the 10 wt.% Ni-doped CuS NPs exhibit a maximum crystallite size of 41 nm. The presence of Ni in the doped samples was acknowledged by the existence of Ni 2p 3 ∕ 2 and Ni 2p 1 ∕ 2 peaks at binding energies 851 eV and 873.1 eV, respectively from the XPS spectrum. Optical reflectance decreased with Ni doping and the optical band gap varied from 2.56 eV to 2.4 eV. Specific capacitance increased with Ni doping. Diamagnetic nature of CuS changed to ferromagnetic with Ni doping. The 10 wt.% Ni-doped CuS exhibits a high third-order nonlinear absorption coefficient and susceptibility value. Bacterial growth inhibition nature of CuS improved with Ni doping. Among the doped samples, the 10 wt.% Ni-doped sample exhibits improved electrochemical, third-order nonlinear, magnetic and antibacterial properties. Keeping this as the optimized Ni concentration, chitosan was loaded. Chitosan-loaded samples exhibited a reduction in crystallite size and an increase in band gap. A high specific capacitance of 96 F/g was realized for the chitosan-loaded sample. Saturation magnetization of 10 wt.% CuS:Ni decreased with chitosan loading. Chitosan, a cationic polymer, is loaded on Ni-doped CuS NPs with optimal Ni doping concentration. Electrochemical, third order nonlinear, magnetic, and antibacterial characteristics of chitosan unloaded and loaded CuS:Ni nanoparticles are compared. [ABSTRACT FROM AUTHOR]

In this study, Poly(methacrylic acid-co-diallyldimethylammonium chloride) or Poly(MAA-PDDA) was synthesized as a cationic molecularly imprinted nano-polymer. After in vitro assays such as cytotoxicity assay and hemolysis activity test, this imprinted nano-polymer was examined for targeted Doxorubicin (DOX) delivery in BALB/c mice bearing MCF7 human breast carcinoma cells. In vivo studies of synthesized nanoparticles on BALB/c mice showed their selectivity. Also, it was found that tumor growth delay (TGD) improved from 1.11 in DOX treated group to 2.82 in cationic polymer combined with DOX. Imprinted cationic polymer provides remarkable prevention of tumor growth. Investigating drug deposition in various tissues showed that DOX concentration was considerably more in tumors than in other tissues. [ABSTRACT FROM AUTHOR]

When polycation and polyanion with high density of charge are directly mixed at middle component ratios to prepare interpolymer complex, aggregation and sediment are often encountered. In this work, a novel randomly branched polycation, PTEE, with high density of charge and lots of big hydrophilic groups of 2-hydroxyl-3-ethoxyprop-1-yl, was synthesized and its interpolymer complex with PAA was prepared by direct mixing to examine the effect of big hydrophilic groups on complex formation and stability. The structures of PTEE and its precursor and complex were characterized by 1HNMR and FT-IR. PTEE/PAA complex particle size, size distribution and stability were measured. Results showed that 2-hydroxyl-3-ethoxyprop-1-yl groups obviously improved complex formation and small complex particles were obtained. The largest mean particle size of PTEE/PAA complex was 320 nm, far smaller than the 20,000 nm of the reference polycation without big hydrophylic groups. Results also showed, different from the contribution to complex formation, big hydrophilic groups had no obvious contribution to static standing stability. [ABSTRACT FROM AUTHOR]

Anaerobic process is a promising technique for textile effluent treatment. However, poor solid–liquid separation and residual chemical oxygen demand (COD) in the treated effluent limit its scope for industrial applications. The study analyzed the nature of suspended microbial biomass in the anaerobically treated effluent and further targeted its feasible separation process. The size of the majority of suspended biomass (82%) particles ranged from 500 to 1000 nm. The suspended biomass showed 37.13% hydrophobicity and −15.4 mV zeta potential. The optimization of the coagulation-flocculation (CF) process showed 93% turbidity removal at 400 mg/L of alum, 8 mg/L of a cationic polymer and acidic pH 4, through one variable at a time approach. The optimized results using Central Composite Design (CCD) were experimentally validated, and 97% turbidity removal was recorded at 400 mg/L alum concentration, 12 mg/L of the cationic polymer, and pH 3.2. The results obtained were statistically significant, with a high regression coefficient (R2 = 0.97) at 95% confidence limits. The final treated effluent after CF showed 67% COD removal (from 862 ± 40 to 280 ± 14 mg/L) with 83% color removal (from 740 to 124 Hazen). Hence, the integration of the CF process with the anaerobic process could be a promising approach for textile effluent treatment. [ABSTRACT FROM AUTHOR]

Cationic nanomaterials are promising candidates for the development of effective antibacterial agents by taking advantage of the nanoscale effects as well as other exceptional physicochemical properties of nanomaterials. In this study, carboxylated cellulose nanocrystals (cCNCs) derived from softwood pulp were coated with cationic poly(diallyldimethylammonium chloride) of varying molecular weights. The resulting cationic carboxylated cellulose nanocrystals coated with poly(diallyldimethylammonium chloride) (cCNCs–PDDA) nanomaterials were characterized for their structural and morphological properties using Fourier transform infrared spectroscopy, dynamic light scattering, zeta potential, elemental analysis, transmission electron microscopy, and thermogravimetric analysis. Cationic cCNCs–PDDA were investigated for their antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli 23934 and Pseudomonas aeruginosa using a bacterial lawn growth inhibition assay. cCNC–PDDA materials displayed marked antibacterial activity, particularly against Gram-positive Staphylococcus aureus. Overall, our results indicated that cCNCs–PDDA could be a potential candidate for antibacterial applications such as antibacterial surfaces or coatings. [ABSTRACT FROM AUTHOR]

Polyamidoamine (PAMAM) dendrimer has received much attention as an alternative to polyethylenimine (PEI) for gene delivery due to the relatively low cytotoxicity. In general, low generational PAMAM dendrimers have better biocompatibility than high generational dendrimers but suffer reduced transfection efficiency. Transfection efficiency can be improved by the modification of the polymer with nuclear localization signal (NLS) peptides. In this study, we modified low generational cystamine core PAMAM dendrimers (cPAMAM, generation 0, 1 and 2) with a lactoferrin-derived nuclear localization signal (NLS) peptide and evaluated transfection efficiency and cytotoxicity as a function of the number of conjugated NLS peptides using NIH 3T3, MCF-7 and human dermal fibroblasts (HDFs). The transfection efficiency of NLS-modified cPAMAM G2 was the highest among the cPAMAM derivatives and similar or higher than PEI 25 kDa. The cytotoxicity of cPAMAM derivatives was generation-dependent and significantly lower than PEI 25 kDa. Our study indicates that cPAMAM G2 conjugated with NLS is a promising candidate for gene delivery applications. [ABSTRACT FROM AUTHOR]

Poly(diallyldimethylammonium chloride) (PDADMAC) is a useful material due to its high charge density and alkaline stability, but its hydrophilic nature limits applications to those where the dissolved polymer is appropriate. To make polymers suitable for applications as films and membranes containing the diallyldimethylammonium moiety, multiblock copolymers of polyaramides (PA) and polyimides (PI), materials known for their excellent physical properties and stabilities, were synthesized. Aminophenyl difunctionalized PDADMAC oligomers were synthesized using a disulfide iniferter then counterion exchanged to the hexafluorophosphate anion to produce telechelic oligomers with good solubility in polar aprotic solvents. The oligomers were reacted in situ with the proper difunctional monomers to produce PA, polyetheraramides, PI, and polyetherimides. All the classes of copolymers were synthesized over a range of compositions at high yield and material properties were demonstrated to be a result of both the backbone chemistry and the composition. Several of the synthesized copolymers formed films with good clarity, strength, and flexibility. The copolymers containing ether linkages had increased backbone flexibility and demonstrated better film‐forming properties. The multiblock copolyaramides and copolyimides demonstrate a method to produce materials with excellent thermal stability and good strength and flexibility, making them uniquely capable of serving as water insoluble, cationic films, and membranes. [ABSTRACT FROM AUTHOR]

Applications of haloalkane dehalogenase DhaA in biocatalysis are limited by its unfavorable performance in organic solvents. Our previous work proved that mutations of surface positive-charged residues enhanced the organic solvent resistance of DhaA, which inspired us to explore the effect of cationic polymers on DhaA in organic solvents. Remarkably boosted performance was achieved in different organic solvent solutions by introducing cationic polymers, for example, there was a 6.1-fold activity increase with poly(allylamine hydrochloride) and a 5.5-fold activity increase with poly(ethylene imine) in 40 vol.% dimethylsulfoxide. The presence of cationic polymers protected DhaA from damage by organic solvents and increased the substrate concentration around the enzyme-polymer complex. Fluorescence spectroscopy and molecular dynamics simulations revealed that the binding of cationic polymers onto DhaA weakened the interactions between organic solvents and DhaA, decreased the organic solvent solvation level around DhaA, and enhanced the structural stability of DhaA in organic solvents. This comprehensive understanding of the effect of cationic polymers on DhaA can help to broaden the applications of DhaA in organic solvent-involved biocatalysis.

Oil contamination is problematic in subaqueous environments. Here, a cationic poly(N,N‐dimethyl‐N‐(ethoxycarbonylmethyl)‐N‐[2′‐(methacryloyloxy)ethyl]‐ ammonium chloride) (PCBMAE) was synthesized, and a one‐step approach of dopamine‐assisted codeposition was used to generate PCBMAE/polydopamine (PDA) superhydrophilic and underwater superoleophobic coatings coated on a stainless steel mesh for oil/water separation. The structures, surface morphologies, and properties of the coatings were analyzed by IR, SEM, TGA, and contact angle measurements. During deposition at a PCBMAE and DA mass ratio of 1:1, PCBMAE/PDA mixture particles uniformly adhered to the skeletons of the mesh, increased the surface roughness, created enriched surface micro/nanostructures, and reduced the surface energy of the coating. This endowed the metal mesh with superhydrophilicity and underwater superoleophobicity (oil contact angle 163°) without blocking the mesh, and the deposition density was 0.26 mg/cm2. The separation efficiency of the coated mesh was 99.6% for the first castor oil/water separation and dropped to 98.0% after 5 cycles. After 25 cycles, the separation efficiency was still higher than 95%. The PCBMAE/PDA codeposited mesh exhibited high oil/water separation efficiency, stable mechanical properties, and weather stability under different harsh environments, making it a promising separation material for future industrial applications. [ABSTRACT FROM AUTHOR]

Deposition plays an important role in the active delivery and efficiency of hair and skin formulations since it allows active compounds to interact with surfaces in order to achieve the product's desired performance characteristics. Therefore, it is essential to study the surface activity and behavior of certain compounds that are frequently used in cosmetic and pharmaceutical formulations in order to understand how they interact with relevant biological surfaces, such as hair and skin. We chose to study the surfactants and conditioning agents utilized in the formulation of conditioning shampoos, which are usually designed to be able to achieve the deposition of these substances on the hair and scalp to provide lubrication and better conditioning for hair fibers, facilitating detangling and providing a better feel. In this study, cationic polymer and salt fractions were varied to obtain eighteen different conditioning shampoo formulations in which the deposition was measured by utilizing a nanoplasmonic sensing technology instrument. Moreover, a wet combing test was performed for each of the formulations to investigate if there was any correlation between the combing force and the surface deposition. The complete study was performed using a sustainable anionic surfactant in order to compare the results with those obtained from the traditional formulations. [ABSTRACT FROM AUTHOR]

Interpolyelectrolyte complexes (IPECs) formed by the interaction of two oppositely charged polyelectrolytes have been proposed as soil structure stabilizers. However, little is known about the environmental safety of IPECs. The goal of this study was to investigate the toxicity of a positively charged IPEC formed by two commercial polymers, namely the cationic biopolymer poly(diallyldimethylammonium chloride) (PDDA) and the anionic biopolymer lignohumate (LH), a humic-based plant growth promoter. Toxicity was assessed using cultures of the bacteria Escherichia coli, the ciliate Paramecium caudatum, mammalian (Bos taurus) spermatozoa in vitro, and three plant species (Sinapis alba, Raphanus sativus, and Triticum durum). The responses of test organisms were evaluated in contact with (1) polymer and water and (2) polymer and soil. In water, PDDA and IPEC were highly toxic to bacteria and ciliates at all concentrations and less toxic to mammalian cells. Higher plants were less sensitive to the polymers, and the toxicity progressively decreased in the order PDDA > IPEC > LH. In soil matrices; the phytotoxicity of PDDA and IPEC was found to be quite low, and none of the polymers was toxic to plants at concentrations that allowed the formation of polymeric soil crusts against erosion. This is because the toxicity of cationic polymers decreases as they enter the soil matrix and bind to organic matter and minerals. [ABSTRACT FROM AUTHOR]

Cationic polymers are considered by the scientific and regulatory communities as a group of greater interest amongst the polymers in commerce. As a category, relatively little hazard information is available in the public literature. Very few examples exist of published, high‐quality polymer characterization and quantification of exposure. In the present study we describe a series of fish embryo toxicity (FET) and fish gill cytotoxicity assays used to establish a baseline understanding of several representative polyquaternium categories (PQ‐6, PQ‐10, PQ‐16) in animal alternative models, accompanied by high‐quality analytical characterization. Materials were chosen to encompass a range of molecular weights and charge densities to determine the influence of test material characteristics on toxicity. Both chorionated and dechorionated FET assays were generally similar to published acute fish toxicity data. Toxicity was correlated with cationic polymer charge density, and not with molecular weight, and was a combination of physical effects and likely toxicity at the site of action. Toxicity could be ameliorated by humic acid in a dose‐dependent manner. Fish gill cytotoxicity results were orders of magnitude less sensitive than FET test responses. Environ Toxicol Chem 2022;41:2259–2272. © 2022 SETAC [ABSTRACT FROM AUTHOR]

Vancomycin (VAN) is unable to penetrate the outer membrane of Gram-negative bacteria and reach the target site. One approach to overcome this limitation is to associate it with compounds with permeabilizing or antimicrobial properties. Eudragit E100® (Eu) is a cationic polymer insufficiently characterized for its potential antimicrobial action. Eu-VAN combinations were characterized, the antimicrobial efficacy against Pseudomonas aeruginosa was evaluated and previous studies on the effects of Eu on bacterial envelopes were extended. Time-kill assays showed eradication of P. aeruginosa within 3–6 h exposure to Eu-VAN, whilst VAN was ineffective. Eu showed regrowth in 24 h and delayed colony pigmentation. Although permeabilization of bacterial envelopes or morphological alterations observed by TEM and flow cytometry after exposure to Eu were insufficient to cause bacterial death, they allowed access of VAN to the target site, since Eu-VAN/Van-FL-treated cultures showed fluorescent staining in all bacterial cells, indicating Van-FL internalization. Consequently, Eu potentiated the activity of an otherwise inactive antibiotic against P. aeruginosa. Moreover, Eu-VAN combinations exhibited improved physicochemical properties and could be used in the development of therapeutic alternatives in the treatment of bacterial keratitis. [ABSTRACT FROM AUTHOR]

An ideal carrier that delivers small interfering RNA (siRNA) should be designed based on two criteria: high gene transfection efficiency and low cytotoxicity. In this work, arginine was used to modify polyvinylamine (PVAm) to form a novel PVAm derivative (PVAm‐Arg) for siRNA delivery and the derivative was characterized using Fourier transform infrared spectroscopy. PVAm‐Arg/siRNA complexes were formed by the self‐assembly method. The zeta potential and size of the complexes were measured using electrophoretic light scattering and dynamic light scattering, respectively. The siRNA binding capacity of PVAm‐Arg was assessed using gel retardation assay. The results showed that PVAm‐Arg derivatives can bind siRNA effectively and form complexes with sizes of about 72 ± 2 nm. What is more, the ability of PVAm‐Arg to condense siRNA was better than that of PVAm. Cytotoxicity assay with RSC96 cells also showed that PVAm‐Arg had lower cytotoxicity compared with PVAm. In in vitro cellular uptake assay, PVAm‐Arg showed good transfection efficiency. Therefore, we concluded that PVAm‐Arg would be a promising candidate as a gene delivery vector. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

In the petroleum industry, water-soluble polymers can be used as oil displacement agents. However, the use of water-soluble polymers is limited because of poor temperature and salt resistance. To improve temperature and salt resistance, a weakly cationic polymer with large side groups (PAM/AMPS/VI) was prepared by copolymerizing acrylamide (AM) with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and 1-vinylimidazole (VI). The viscosity of PAM/AMPS/VI water solutions can be increased more than 20 mPa·s compared with PAM/AMPS. In addition, the viscosity of the solution increased continuously after aging at 80 °C, showing good temperature and salt stability. The protonated tertiary amine in the imidazole ring electrostatically interacts with the sulfonic group, increasing the viscosity and salt resistance of the polymer. The five-membered ring of imidazole also enhances the rigidity of the polymer chain and improves the temperature tolerance. As a confirm of the result, a complete spatial network of PAM/AMPS/VI was observed in scanning electron microscopy (SEM) micrographs. Using weak cationic polymers with large side groups can provide a reference for the design of new temperature tolerance and salt resistant polymer. [ABSTRACT FROM AUTHOR]

Infection control measures to prevent viral and bacterial infection spread are critical to maintaining a healthy environment. Pathogens such as viruses and pyogenic bacteria can cause infectious complications. Viruses such as SARS-CoV-2 are known to spread through the aerosol route and on fomite surfaces, lasting for a prolonged time in the environment. Developing technologies to mitigate the spread of pathogens through airborne routes and on surfaces is critical, especially for patients at high risk for infectious complications. Multifunctional coatings with a broad capacity to bind pathogens that result in inactivation can disrupt infectious spread through aerosol and inanimate surface spread. This study uses C-POLAR, a proprietary cationic, polyamine, organic polymer with a charged, dielectric property coated onto air filtration material and textiles. Using both SARS-CoV-2 live viral particles and bovine coronavirus models, C-POLAR-treated material shows a dramatic 2-log reduction in circulating viral inoculum. This reduction is consistent in a static room model, indicating simple airflow through a static C-POLAR hanging can capture significant airborne particles. Finally, Gram-positive and Gram-negative bacteria are applied to C-POLAR textiles using a viability indicator to demonstrate eradication on fomite surfaces. These data suggest that a cationic polymer surface can capture and eradicate human pathogens, potentially interrupting the infectious spread for a more resilient environment., Importance: Infection control is critical for maintaining a healthy home, work, and hospital environment. We test a cationic polymer capable of capturing and eradicating viral and bacterial pathogens by applying the polymer to the air filtration material and textiles. The data suggest that the simple addition of cationic material can result in the improvement of an infectious resilient environment against viral and bacterial pathogens., Competing Interests: The authors declare no conflict of interest.

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.