Polyethylene Glycol Research Articles

Effects of Polyethylene Glycol and Chloride Ion on Copper Electroplating at High Current Density

To determine the effect of Polyethylene Glycol(PEG) and Chloride ions(Cl-) as additives during electroplating, this study used interaction plots of various characteristics of the electroplated Cu foils for analyses. Crystals of about 2 µm in size were observed on the surface of Cu electroplated in the electrolyte without PEG. When 30-100 ppm PEG was added, the crystal size and surface roughness decreased in relation to the amount of PEG. However, there were lots of dented areas, which became fewer as Chloride ions were increased from 20 ppm to 40 ppm. When 300 ppm PEG was added, the dented areas were not observed. Nevertheless, the surface morphology was very irregular and rough. In the group with 30-100 ppm PEG added, the resistivity decreased due to the increase in grain size. Moreover, the tendency of crystals to grow preferentially in the direction of the (111) plane led to an increased resistance to EM(electro-migration). When 40 ppm of chloride ions and 100 ppm of PEG were added, the yield strength increased by 22.4%, the tensile strength increased by 28.7%, and the elongation increased by 293.5% compared to the group without additives. This study showed that a combination of appropriate additives and amounts was required to form copper foils with low surface roughness, excellent electrical properties, and EM resistance and low corrosion rate. Therefore, with 100 ppm added PEG, it is necessary to add 20 ppm of chloride ions to ensure a low corrosion rate and 40 ppm of chloride ions for high mechanical properties.

Study on Internal Standards Applicable to the Detection of Recombinant Erythropoietin.

With the discovery of the variant c.577del in the EPO gene, the procedure for detecting the presence of recombinant erythropoietin (rEPO) has become complicated and time-consuming. To address this situation, an rEPO confirmation method that uses reverse-normal immunopurification coupled with western blotting (WB) and sodium N-lauroylsarcosinate polyacrylamide gel electrophoresis (SAR-PAGE), which can detect the EPO variant (VAR-EPO) and rEPO with anti-VAR-EPO and anti-EPO antibodies, has been developed. Therefore, it is necessary to develop an internal standard (IS) that can be recognized by an anti-VAR-EPO antibody to monitor reverse immunopurification, ensuring the reliability and accuracy of the analysis. In this study, we constructed an IS based on VAR-EPO modified with polyethylene glycol (PEG) and then assessed its reliability and applicability in doping analysis. The data provided here show that the obtained PEGylated VAR-EPO can be used as an IS to monitor the detection of not only rEPO and VAR-EPO but also EPO receptor agonists in urine samples.

Preparation and Performance of ATH-OPC-PEG Bilayer Microcapsules Based on Targeted Flame Retardation Against Spontaneous Coal Combustion

ABSTRACT In order to solve the problem of spontaneous combustion of coal in the air-mining area, ATH-OPC-PEG double-layer flame retardant microcapsules were prepared. The environmentally friendly flame retardant aluminum hydroxide (ATH) was selected as the core material of the microcapsules. Due to the high action temperature and late action time of ATH, sodium alginate-modified melamine-melamine resin was used as the first layer of shell material of microcapsules to coat ATH. Then molten polyethylene glycol (PEG) mixed with the environmentally friendly strong antioxidant proanthocyanidin (OPC) was used as the second layer of shell material for the secondary coating of microcapsules. Providing antioxidant properties to microcapsules. The surface morphology, dispersion, encapsulation, pyrolysis, and flame retardant properties of the microcapsules were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TG), and cone calorimeter. On this basis, the microcapsules were mechanically mixed with coal samples, and four coal samples were prepared for combustion tests. The results showed that ATH-OPC-PEG microcapsules prolonged the water locking time and increased the TGA by 1.162%. According to the cone calorimeter analysis, the CO and CO2 release rates of microcapsule-treated coal were reduced by 27.90% and 13.98% compared with that of pure coal. This study provides directional solution ideas for solving different stages of spontaneous combustion of coal in the mining area, and enriches the technical means of fire prevention and extinguishing.

Comparing 1-L and 2-L Polyethylene Glycol with Ascorbic Acid for Small Bowel Capsule Endoscopy: A Randomized Controlled Trial.

Small bowel capsule endoscopy (SBCE) has become the standard for initial evaluation in the diagnosis of small bowel lesions. Although optimal visualization of the mucosa is important, patients experience difficulty in consuming a large volume of bowel preparation agents. This study aimed to compare the efficacy and safety of 1-L polyethylene glycol (PEG) with ascorbic acid (AA) and 2-L PEG with AA. In this prospective, multicenter, non-inferiority study, patients who received SBCE were randomly assigned to consume 1-L PEG with AA or 2-L PEG with AA for small bowel preparation. The primary outcome was adequate small bowel visibility quality (SBVQ). The secondary outcomes included diagnostic yield, cecal complete rate, and adverse events. One hundred and forty patients were enrolled in this study, 70 patients per group. In the per-protocol analysis, there were no significant differences in the adequate SBVQ rate (94.0% vs 94.3%; risk difference, -0.3; 95% confidence interval, -8.1 to 7.6; p=1.000), diagnostic yield rate (49.3% vs 48.6%, p=0.936), or cecal complete rate (88.1% vs 92.9%, p=0.338) between the 1-L PEG with AA group and 2-L PEG with AA group. The incidence of adverse events did not differ significantly between the groups (12.9% vs 11.9%, p=0.871). One liter-PEG with AA is not inferior to 2-L PEG with AA in terms of adequate SBVQ for SBCE. One liter-PEG with AA can be recommended as the standard method for bowel cleansing for SBCE.

Enhancing the porosity of biphasic calcium phosphate using polyethylene glycol as the porogen for bone regeneration applications

Biphasic calcium phosphate (BCP) has been used as a material to support bone grafting, repair, recovery, and regeneration over the past decades. However, the inherent weakness of BCP is its low porosity, which limits the infiltration, differentiation, and proliferation of bone cells. To address this issue, porous BCP was synthesized using polyethylene glycol (PEG) 1000 with weight ratio ranging from 20%-60% in BCP as the porogen through the powder-forming method. Analytical methods such as Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy were used to demonstrate the purity, morphology and functional groups on the material surface of the obtained BCP samples. Structurally, the BCP sample with 60% PEG, named B60, possessed the highest porosity of 71% and its pore diameters ranging from 5 to 75 µm. Besides, thein vitrobiocompatibility of B60 material have been demonstrated on the L929 cell line (90% cell viability) and simulated body fluid (apatite formation after 1 d). These results suggested that B60 should be further studied as a promising artificial material for bone regenerating applications.

Metal Doping Enabling Defective CoMo-Layered Double Hydroxide Nanosheets as Highly Efficient Photosensitizers for NIR-II Photodynamic Cancer Therapy.

Photodynamic therapy (PDT) is attracting widespread attention as a promising strategy for tumor treatment. However, the efficacy of PDT is severely limited by the insufficient tissue penetration depth of the light source and low reactive oxygen species (ROS) generation efficiency. Herein, the metal doping strategy is reported to construct a series of defect-rich M-doped amorphous CoMo-layered double hydroxide (a-M-CoMo-LDH, M = Mn, Cu, Al, Ni, Mg, Zn) photosensitizers (PSs) for NIR-II PDT. Especially, M-doped CoMo-LDH nanosheets are synthesized through a simple hydrothermal method and then etched by acid treatment to prepare defect-rich a-M-CoMo-LDH nanosheets. Under NIR-II 1270 nm laser irradiation, the defect-rich a-Zn-CoMo-LDH nanosheets exhibit the optimal PDT performance compared with other a-M-CoMo-LDH nanosheets, and also possess much higher ROS production activity (3.9 times) than that of the pristine a-CoMo-LDH, with a singlet oxygen quantum yield up to 1.86, which is the highest among all the reported PSs. After polyethylene glycol (PEG) modification, the a-Zn-CoMo-LDH-PEG nanosheets can function as an effective inorganic PS for PDT, effectively inducing cell apoptosis in vitro and eradicating tumors in vivo. Notably, transcriptome sequencing analysis and further molecular validation highlight the critical role of the apoptotic/p53/AMPK/oxidative phosphorylation signaling pathways in a-Zn-CoMo-LDH-PEG-induced cancer cell apoptosis.

Toward Intracellular Delivery: Aliphatic Polycarbonates with Pendant Thiol-Reactive Thiosulfonates for Reversible Postpolymerization Modification.

Postpolymerization modifications are valuable techniques for creating functional polymers that are challenging to synthesize directly. This study presents aliphatic polycarbonates with pendant thiol-reactive groups for disulfide formation with mercaptans. The reductive responsive nature of this reaction allows for reversible postpolymerization modifications on biodegradable scaffolds. Six-membered cyclic carbonate monomers with pendant thiosulfonate groups were synthesized and polymerized using controlled organocatalytic ring-opening polymerization, yielding polymers with narrow molecular weight dispersities (Đ = 1.2) and intact reactive thiosulfonate side chains. Reversible modification with benzyl mercaptans achieved high degrees of disulfide modification. Additionally, thiol-reactive carbonate monomers were block-copolymerized onto polyethylene glycol (mPEG113) and then converted into benzyl disulfides, while the block copolymers' hydroxyl end groups remained available for fluorescent dye labeling. The amphiphilic block copolymers self-assembled in water into micelles (∼33 nm diameter), capable of encapsulating hydrophobic molecules. These micelles successfully delivered hydrophobic dyes into macrophages, indicating the potential for intracellular drug delivery.

Aerosol Fluorescent Labeling via Probe Molecule Volatilization.

The physicochemical properties of aerosols, including hygroscopicity, phase state, pH, and viscosity, influence important processes ranging from virus transmission and pulmonary drug delivery to atmospheric light scattering and chemical reactivity. Despite their importance, measurements of these key properties in aerosols remain experimentally challenging due to small particle sizes and low mass densities in air. Fluorescence probe spectroscopy is one of the only analytical techniques that is capable of experimentally determining these properties in situ in a nondestructive and minimally perturbative manner. However, the application of fluorescence probe spectroscopy to important classes of aerosols including exhaled respiratory and ambient atmospheric aerosols has been limited due to a typical reliance on premixing the probe molecule with particle constituents prior to particle generation, which is not always possible. Here, a method for aerosol fluorescent labeling based on probe molecule volatilization is developed. The method is first applied to label model polyethylene glycol (PEG) aerosols with two different polarity-sensitive probes, Nile red and Prodan. The similarity of the relative humidity-dependent fluorescent emission of each probe between prelabeled and volatilized-probe PEG particles validated the methodology. A preliminary application of the technique to indicate the hygroscopicity of artificial saliva respiratory particles and model atmospheric secondary organic aerosol particles is demonstrated. The methodology developed here paves the way for future studies applying powerful fluorescent probe-based analytical techniques to study exhaled or natural aerosols for which fluorescent prelabeling is not possible.

Modulation of Ion Transport in Nanopores Using Polyethylene Glycol.

Ion transport in nanopores is crucial for various biological and technological processes, exhibiting unique behaviors compared to bulk solutions. In this study, we systematically explore how polyethylene glycol (PEG) modulates ion transport within a conical nanopore. Our experiments reveal that introducing PEG into the ionic solution induces a reversal in ion current rectification (ICR). We further investigate the impact of PEG concentration, molecular weight, nanopore size, and cation type on ion transport. Additionally, we assess three different configurations of PEG introduction, identifying diffusive flow driven by an asymmetric cation distribution within the nanopore as a dominant transport mechanism. Our results confirm that the interactions between PEG and cations significantly affect ion transport properties. These findings advance our understanding of macromolecular crowding effects on ion transport and suggest potential applications in iontronic devices and biomolecule sensing.

Shape Effect of Polymer-Based Multilayer Microcapsules on Cellular Internalization.

The intracellular fate of drug carriers had received extensive attention, which was profoundly influenced by the shapes of carriers. However, it has not been fully addressed due to the lack of effective strategies to prepare carriers with different shapes and the interference of other parameters (such as stiffness and chemistry of the shaped particle and the different cell lines). In this work, polymer-based microcapsules with different shapes (spherical, peanut, dumbbell, and cubic) but the same surface chemistry were engineered through the alternative deposition of polyethylenimine (PEI) and polyethylene glycol (PEG) onto the sacrificial CaCO3 templates with different well-defined shapes. Various techniques (SEM, CLSM, AFM, FTIR, and XPS) were utilized to determine the shapes and chemical composition of these microcapsules. The effect of microcapsule shape on cellular internalization kinetics and the endocytosis mechanism was thoroughly studied, and dumbbell and cubic microcapsules showed greater internalization rates and amounts than spherical and peanut microcapsules. These microcapsules were internalized through micropinocytosis, and the shapes had no obvious effect on the endocytosis mechanism. This work provides a wealth of information about the relationship between the shape of microcapsules and their performance in cellular internalization, which will be of great help in the development of related drug carriers.

A pH-responsive dual-network biopolysaccharide hydrogel with enhanced self-healing and controlled drug release properties.

Traditional hydrogels based on Schiff base reactions frequently encounter issues with rapid drug release when employed as drug delivery systems owing to their susceptibility to hydrolysis under acidic conditions. It is, therefore, necessary to implement improvements to regulate the drug release behavior. In this study, a dual-network and pH-responsive biopolysaccharide hydrogel was developed, which is self-healing, injectable and biocompatible. Most importantly, the hydrogel has excellent tunability for controlled drug release. The hydrogel consisted of a primary network of dibenzaldehyde-functionalized poly(ethylene glycol) (DP) and chitosan (CS) formed through a Schiff base reaction and a secondary network of sodium alginate (SA) and CS formed through electrostatic interactions. It was found that the DP-CS-2%SA hydrogel can prolong the release duration up to four-fold compared to the single-network DP-CS hydrogel at a given release threshold. Significantly, by adjusting the relationship between the two effects through the amount of SA, the release modifiability of drug delivery systems has been greatly enhanced. This study could significantly enhance the tunability of hydrogel drug delivery systems.

Measurement of Covalent Bond Formation in Light-Curing Hydrogels Predicts Physical Stability under Flow.

Photo-crosslinking hydrogels are promising for tissue engineering and regenerative medicine, but challenges in reaction monitoring often leave their optimization subject to trial and error. The stability of crosslinked gels under fluid flow, as in the case of a microfluidic device, is particularly challenging to predict, both because of obstacles inherent to solid-state macromolecular analysis that prevent accurate chemical monitoring and because stability is dependent on size of the patterned features. To solve both problems, we obtained 1H NMR spectra of cured hydrogels which were enzymatically degraded. This allowed us to take advantage of the high-resolution that solution NMR provides. This unique approach enabled the measurement of degree of cross-linking (DoC) and prediction of material stability under physiological fluid flow. We showed that NMR spectra of enzyme-digested gels successfully reported on DoC as a function of light exposure and wavelength within two classes of photo-cross-linkable hydrogels: methacryloyl-modified gelatin and a composite of thiol-modified gelatin and norbornene-terminated polyethylene glycol. This approach revealed that a threshold DoC was required for patterned features in each material to become stable and that smaller features required a higher DoC for stability. Finally, we demonstrated that DoC was predictive of the stability of architecturally complex features when photopatterning, underscoring the value of monitoring DoC when using light-reactive gels. We anticipate that the ability to quantify chemical cross-links will accelerate the design of advanced hydrogel materials for structurally demanding applications such as photopatterning and bioprinting.

A green, versatile, and facile strategy for anti-biofouling surface with ultra-high graft density polyethylene glycol

Implantable catheters are susceptible to severe complications due to non-specific protein adhesion on their surfaces. Polyethylene glycol (PEG) coatings, the gold standard for resistance to non-specific protein adhesion, present a challenge in achieving high-density grafting, which significantly restricts their use as anti-biofouling coatings. Herein, we exploited the strong interaction between polyphenols (PCs) and polycations (K6-PEG) to graft PEG onto the surface of PC-Cu (A network of metal polyphenols composed of proanthocyanidins and metal copper ions, with expectation for the coating with excellent resistance to non-specific protein adhesion (PC-Cu@K6-PEG). The introduction of K6-PEG resulted in enhanced stability and modulus of PC-Cu, as well as a reduction in the surface adhesion energy and contact angle of PC-Cu. In contrast to previously reported PEG coatings, PC-Cu@K6-PEG exhibited a markedly elevated grafting density of PEG (4.06 chains/nm²), which was more than double the highest value previously reported (1.9 chains/nm²), due to the diffusing ability of K6-PEG throughout the PC-Cu networks. PC-Cu@K6-PEG displays robust resistance to a variety of proteins, microbials, and platelet attachment, thereby preventing thrombosis. The coating ability of PC-Cu onto diverse substrates, combined with the simple, straightforward and environmentally benign process of fabricating PC-Cu@K6-PEG, suggests that this strategy has significant potential for use in anti-biofouling surfaces.

Tribological Properties of Polydimethylsiloxane Grafted with Poly(Ethylene Glycol) Methyl Ether Methacrylate Under Water Lubrication

Polydimethylsiloxane (PDMS) is a polymer material characterized by its flexibility, biocompatibility, non-toxicity, excellent stability, and high transparency. It is also easy to process and allows for control over its physical properties. However, its inherent hydrophobicity limits its application in certain fields. To address this limitation, research is being conducted to modify the surface properties of PDMS through polymer grafting. In this work, poly(ethylene glycol) methyl ether methacrylate (mPEG-MA) was grafted onto the PDMS surface to convert its hydrophobic characteristics to hydrophilicity. The tribological properties of the modified PDMS were then evaluated under conditions of hydrophilicity and water lubrication. Polymer grafting was performed by generating radicals on the surface of PDMS through ultraviolet (UV) irradiation using a photoinitiator, followed by grafting with mPEG-MA. The water contact angle, which serves as an indicator of hydrophilicity, was measured and revealed a decrease in the contact angle as the conditions for mPEG-MA grafting were intensified, signifying an increase in hydrophilicity. Additionally, the tribological properties under water lubrication improved with a higher degree of mPEG-MA grafting. Notably, PDMS grafted with a 20 wt.% mPEG-MA aqueous solution via UV irradiation for 12 h consistently maintained a coefficient of friction (COF) of less than 0.02 under water lubrication. Surface damage was observed locally in the dimples only under a load of 3 N.

Ubiquitin Ligase U-Box51 Positively Regulates Drought Stress in Potato (Solanum tuberosum L.)

The ubiquitin-proteasome system (UPS) is a key protein degradation pathway in eukaryotes, in which E3 ubiquitin ligases mediate protein ubiquitination, directly or indirectly targeting substrate proteins to regulate various biological processes, including plant growth, hormone signaling, immune responses, and adaptation to abiotic stress. In this study, we identified plant U-box protein 51 in Solanum tuberosum (StPUB51) as an E3 ubiquitin ligase through transcriptomic analysis, and used it as a candidate gene for gene-function analysis. Quantitative real-time PCR (qRT-PCR) was used to examine StPUB51 expression across different tissues, and its expression patterns under simulated drought stress induced by polyethylene glycol (PEG 6000) were assessed. Transgenic plants overexpressing StPUB51 and plants with down-regulated StPUB51 expression were generated to evaluate drought tolerance. The activities of key antioxidant enzymes-superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) as well as malondialdehyde (MDA) content in transgenic plants’ leaves were measured under drought conditions. Protein–protein interactions involving StPUB51 were explored via yeast two-hybrid (Y2H) screening, with interaction verification by bimolecular fluorescence complementation (BiFC). StPUB51 was predominantly expressed in stems, with lower expression observed in tubers, and its expression was significantly upregulated in response to 20% PEG-6000 simulated drought. Subcellular localization assays revealed nuclear localization of the StPUB51 protein. Under drought stress, StPUB51-overexpressing plants exhibited enhanced SOD, POD, and CAT activities and reduced MDA levels, in contrast to plants with suppressed StPUB51 expression. Y2H and BiFC analyses identified two interacting proteins, StSKP2A and StGATA1, which may be functionally linked to StPUB51. Collectively, these findings suggest that StPUB51 plays a positive regulatory role in drought tolerance, enhancing resilience in potato growth and stress adaptation.

Genome-Wide Identification of the GbUBC Gene Family in Sea-Island Cotton (Gossypium barbadense) and the Active Regulation of Drought Resistance in Cotton by GbUBC23

Cotton is an economically critical crop worldwide, and drought stress strongly affects its growth and development. Ubiquitination modifies protein activity and is crucial in numerous biological processes. Ubiquitin-conjugating enzymes serve as intermediaries in the protein ubiquitination process and play important roles in plant responses to abiotic stress. However, the impact of ubiquitination on the response of cotton to abiotic stress is not fully understood. Bioinformatic methods were employed in this study to analyze the physiochemical characteristics, gene structure, collinearity, expression patterns, and evolutionary relationships of GbUBC gene family members in sea-island cotton. In sea-island cotton, a minimum of 125 GbUBC genes are irregularly distributed across the 26 chromosomes, with multiple instances of gene duplication observed among the members. Phylogenetic analysis categorized the GbUBC gene family into 15 ubiquitin-conjugating enzyme (E2) subgroups, one ubiquitin E2 enzyme variant (UEV) subgroup, and one COP10 subgroup. GbUBC gene expression pattern analyses revealed that most GbUBC genes responded differently to cold, heat, NaCl, and polyethylene glycol (PEG) treatments, with certain GbUBC genes exhibiting high expression levels in specific fiber development period and organs. Furthermore, molecular biology methods were employed to elucidate the biological functions of GbUBC23. The GbUBC23 gene was highly expressed in the cotyledons of sea-island cotton and was activated by PEG treatment. GbUBC23 is localized to the nucleus and cytomembrane. The silencing of the GbUBC23 gene under drought conditions led to decreased drought tolerance and survival rates in sea-island cotton. Compared with those in the control plants, the activity of proline and superoxide dismutase and the expression levels of the drought-induced genes GbNCED3, GbRD22, GbRD26 were significantly lower, but the levels of malondialdehyde and hydrogen peroxide were significantly higher. Our findings revealed 125 members of the GbUBC gene family in sea-island cotton, with the GbUBC23 gene critically contributing to the abiotic stress response. These findings indicate that the GbUBC gene family may play a crucial role in the drought stress response in sea-island cotton.

The synergy of ACC deaminase producing plant growth-promoting microbes provide drought tolerance in Ocimum basilicum L. cv. “Saumya”

The use of plant growth-promoting microorganisms is an effective agricultural practice to improve plant growth, especially under abiotic stress. In this study, the combined impact of three plant growth-promoting bacteria (PGPB) namely Brevibacterium halotolerans (Sd-6), Burkholderia cepacia (Art-7), Bacillus subtilis (Ldr-2) were tested with Trichoderma harzianum (Th) (possessing ACC deaminase producing activity) in Ocimum basilicum L. cv. “Saumya” to reduce drought-induced damages to the plants under different level of drought stress [i.e. well-watered (100 %), moderate (60 %), severe (40 %)]. These PGPB strains, along with Th, were found to be tolerant against osmotic stress when tested in growth media containing different concentrations of polyethylene glycol (PEG 8000), and all were found to endure -0.99 MPa water potential. Compared to non-inoculated control, Th+Ldr-2 treatment improved fresh herb weight (62.45 %) and oil content (61.54 %) and higher photosynthetic rate under severe drought. Besides, in relation to control, the above treatment enhanced nutrient uptake, reduced ABA, ACC as well as ethylene levels and increased IAA content in addition to an increase in important constituents of essential oil, indicating better performance in terms of plant growth under drought. Higher RWC, decreased MDA, and reduced antioxidant activities in Th+Ldr-2 treated plants compared to non-inoculated control under drought support the mechanism of the microbes providing tolerance against drought. Colony forming unit of microbes and scanning electron microscopy (SEM) study support the effective colonisation behaviour of Th+Ldr-2, which protects plants against drought stress. A consortium of diverse microbes, found to improve plant growth under drought through increased nutrient uptake, reducing the levels of ACC and ABA, improving the content of IAA, antioxidant enzymes probably reducing the effect of drought stress and improving plant biomass could be a useful tool to reduce drought-induced losses in crop plants.

Effects of Preparation Conditions on Performance of PES:PEG Flat Sheet Membrane for MG Dye Separation

This study deals with the morphology and performance properties of a novel thin flat sheet ultrafiltration membrane; Malachite Green (MG) dye filtration behavior was evaluated in the cross-flow filtration system. The prepared membranes included the incorporation of 16 wt. % of polyether sulfone (PES)/DMF and 5 wt.% of Polyethylene Glycol (PEG) via the phase inversion process. Adding PEG decreased the internal concentration polarization, improved the membrane hydrophilicity, changed pore morphologies, and enhanced membrane performance. The SEM and AFM tests were used to characterize the composition and structure of the membrane. With different casting conditions, the membrane shape changed. The effect of membrane thickness (100, 150, and 200) µm and coagulation bath properties temperature (15, 25, and 35) °C and composition DMF (10, 20, 30 %) in water on the fabricated membrane were investigated. To evaluate the membrane filtration performance, the fabricated membranes were applied in an ultrafiltration system to treat Malachite Green dye solution at a concentration of (10 ppm) as a model pollutant. Based on the obtained results, the ideal membrane parameters were150 µm in thickness, 35°C in temperature, and 10% in composition DMF; the removal efficiency was observed to be (94.5%, 93%, and 99.5%) while the permeate flux (45, 35 and 30) LMH, respectively.

Polyethylene Glycol‐Based Refolding Kinetic Modulation of CRABP I Protein

ABSTRACTCrowding environment has a significant impact on the folding and stability of protein in biological systems. In this work, we have used four different sizes of a molecular crowder, polyethylene glycol (PEG), to analyze the unfolding and refolding kinetics of an iLBP protein, CRABP I, using urea as chemical denaturant. In general, the stability of the native state of the protein is boosted by the presence of crowding agents in the solution. However, our findings show that not only the type of crowder but also the crowder size played a key role in the effects of excluded volume. In case of lower molecular weight of PEG (M.W. 400), even at 200 g/L concentration, only the viscosity effect is observed, whereas for higher molecular weight of PEG (M.W. 1000), both the viscosity effect and excluded volume effect are noticed, and even at a higher concentration (200 g/L) of PEG 1000, the excluded volume predominates over the viscosity effect. Using the transition state theory, we were also able to determine the free energies of activation for the unfolding and refolding studies from their respective rate constants. Additionally, MD simulation studies provide strong support for our experimental observation. Analysis of secondary structure propensity (SSP) reveals a marked decline in the presence of structural elements (β‐sheet, β‐bridge, turn, and α‐helix) from 81% to 43% over the 1 μs time scale unfolding MD simulation under 8 M urea conditions. Conversely, in a 200 ns refolding simulation, the rate of refolding notably increases at a concentration of 200 g/L PEG 1000.

Investigating Gene Delivery Efficiency of Poly(β‐amino ester) Derived From Poly(ethylene glycol) Diacrylate

AbstractPoly(β‐amino ester) (PβAE)‐based polymers hold promise for bacterial gene transfer due to their ability to form stable complexes with genetic material and facilitate efficient delivery into bacterial cells. These polymers are easily modified to improve uptake and protect DNA or RNA from degradation, providing a safer, more controlled alternative to traditional methods like chemical transformation or electroporation. In this study, we evaluated the gene transformation efficiency of cationic PβAE polymer, which was synthesized through an aza‐Michael addition reaction between piperazine and poly(ethylene glycol) diacrylate. Competent cells from E. coli strain DH5α were prepared with the optimized method using Ca2+ and Mg2+ ions. Different concentrations of the polymer were mixed with pRSET‐EmGFP before transforming into competent cells through the heat shock method. Transformed cells were checked on medium containing ampicillin, and by using colony PCR, transformation efficiency was calculated. Based on our findings, we observed a successful transformation of the EmGFP gene in case of having the polymer. Furthermore, the PβAE at high concentrations (20–100 ng µL−1) increased transformation efficiency more than twice as compared to the case of no polymer added. In conclusion, PβAE can effectively increase transformation efficiency.