Amount Of Polyethylene Glycol Research Articles

The role of PEG/glycerol ratio on the structure and corrosion protection properties of PU-silica coating

In this work, investigation was made of the effect of incorporation of polyethylene glycol (PEG) in glycerol-based PU-silica coatings, with the aim of enhance thermal, mechanical, and corrosion protection properties, and establish a comprehensive knowledge regarding the synthesis of novel hybrid PU coatings with variable PEG/glycerol molar ratio. Nuclear magnetic resonance (13C NMR) and Fourier transform infrared (FTIR) spectroscopy analyses showed the conjugation of the PEG to the PU structure by urethane bonds, with the samples prepared using a higher amount of PEG presenting a less rigid structural conformation. Small-angle X-ray scattering (SAXS) measurements demonstrated a correlation between the inorganic fractal dimensionality and the PEG amount. The increasing PEG content contributes to improve thermal stability, coating roughness, and scratch hardness, that achieves typical values of 230 °C, 115 nm and 6H, respectively. As an anticorrosive barrier for steel, the 1.5 μm thickness coating prepared with 75 % glycerol and 25 % PEG exhibits an impedance modulus exceeding 10 GΩ.cm2 over 28 days in contact with saline solution. This new PEG/glycerol-based PU-silica coating proves highly suitable functional features for anticorrosive applications, offering commendable thermal stability, low thickness, high scratch resistance, and impressive impedance.

Poly(2-methyl-2-oxazoline) as a polyethylene glycol alternative for lipid nanoparticle formulation

Lipid nanoparticles (LNPs) have emerged as the platform of choice for mRNA delivery. Polyethylene glycol (PEG) is considered a key component of currently approved LNP-based delivery systems as it ensures particle stability and shapes various facets of LNP behavior in biological systems. Whilst PEG has numerous characteristics that are favorable for delivery systems, there is a growing body of evidence that suggests that it is immunogenic. Thus, next-generation mRNA therapeutics are likely to benefit from the identification of PEG alternatives. Towards this end, we have assessed the suitability of poly(2-methyl-2-oxazoline) (PMOZ) for LNP-based mRNA delivery. We compared the properties and bioactivities of PMOZ-containing LNPs to that of a standard composition that includes PEG. Decreasing the percentage of PMOZ in formulations improved transfection efficiency and enhanced the immunostimulatory potential. Reducing the PMOZ density was shown to enhanced antigen-specific T-cell responses in vivo. Interestingly, we found that this was not the case for antibody responses. A direct comparison between LNPs that contain the same amount of PEG or PMOZ strongly suggests that the former induces stronger CD8+ T-cell responses while the latter induces superior neutralizing titers. These findings augur well for the further development of PMOZ as a PEG replacement for LNP-based mRNA delivery approaches.

The pivotal role of the polyethylene glycol amount as compatibilizing on the morphological features of silica-based blends

Silica-based hybrid blends at different molecular or nanometer scale have gained a lot of interests from the technological point of view. In particular, several inorganic-organic hybrids find application in the biomedical field. In this context, inorganic SiO2 and hybrids made up of SiO2 and polyethylene glycol (PEG) have been synthesised via the sol-gel route and characterised from the morphological (throught the Atomic Force Microscopy - AFM) and spectroscopic point of view to shed light on their features as possible hybrid biomaterials. AFM investigation allowed for an effective quantitative evaluation of surface roughness of bioactive sol-gel-based materials. The results revealed an increase in material porosity as a function of the PEG amount in the systems, thus highlighting the pivotal role of the PEG amount as compatibilizing on the morphological features of silica-based blends. The co-presence of both the inorganic and organic phases was confirmed by the Fourier-transform infrared spectroscopy (FT-IR). Moreover, the influence of PEG was also investigated by analysing the deconvoluted FT-IR spectra in the range of 1600-750 cm−1.

Twin-screw melt granulation for high-dose paracetamol tablets

Abstract Objectives In this study twin-screw melt granulation (TSMG) was used to produce sustained release formulations and improve the poor compressibility of paracetamol (PMOL). Methods By using various amounts of polyethylene glycol (PEG), a low melting point binder and ethyl cellulose (EC) as insoluble carrier, the formation of high content of PMOL granules occurred at low processing temperatures (55°C). Key findings X-ray diffraction and differential scanning calorimetry analysis showed the presence of partially crystalline PMOL in the extruded granules. Compressed caplet tablets comprising of TSMG granules presented sustained release profiles for 3-4 h depending on the EC concentration. The tablets showed excellent tabletability and low compaction forces were applied. Conclusions TSMG can be used for the processing of drugs with poor compressibility actives for the compression of high-dose tablets.

Development, performance research and shape memory multifunctional exploration of epoxy/PEG shape memory nanofibers

To improve the spinnability of thermoplastic epoxy resin and develop epoxy resin-based shape memory nanofiber materials, polyethylene glycol (PEG) was utilized to regulate the properties of thermoplastic epoxy. The process involved the preparation of thermoplastic epoxy/PEG nanofibers using melt-dispersion and electrospinning techniques. The addition of PEG has enabled the electrospinning of the thermoplastic epoxy, with EPP-5 having the smallest average diameter (227 nm) and EPP-10 showing the most uniform morphology. FTIR analysis confirmed sufficient polymerization of epoxy resin. The water contact angle analysis revealed that an appropriate amount of PEG reduced the hydrophilicity of the nanofiber membranes, with the EPP-10 showing a 14.9 ° increase in water contact angle compared to the EPP-5. The mechanical analysis demonstrated that an appropriate amount of PEG improved the nanofibers’ yield stress, breaking strain, and maximum tensile stress. The EPP-10 exhibited a 3.27 MPa increase in yield stress, a 19.54 % increase in breaking strain, and a 1.17 MPa increase in maximum tensile stress compared to the EPP-5. Thermal analysis showed that epoxy/PEG nanofibers decomposed mainly between 400 ℃ and 500 ℃. Thermomechanical analysis revealed a reduction in the Tg of epoxy/PEG films with the addition of PEG, among which the Tg of EPP-25 was 55.1 ℃ lower than that of EPP-0. The epoxy/PEG nanofiber membrane exhibits excellent shape memory performance, among which the EPP-10 exhibits the best shape recovery effect. In addition, the EPP-10 yarn stretched to 160 % of original length recovered within 25 s, and EPP-10 yarn tied in a temporary shape recovered to original shape within 15 s. In conclusion, by modulating the properties of thermoplastic epoxy through PEG, the spinnability of thermoplastic epoxy was achieved, and shape memory epoxy/PEG nanofibers with potential applications in the field of smart textiles were developed.

Enhancing photoluminescence performance and pH photostability of nitrogen-doped graphene quantum dots via surface-passivated by polyethylene glycol

The photoluminescence (PL) properties of nitrogen-doped graphene quantum dots (NGQDs) are highly dependent on reaction parameters. In this study, we developed new and fast protocols to surface passivate NGQDs with polyethylene glycol (PEG) using microwave irradiation. The resulting NGQDs-PEG exhibited highly stable PL with an emission peak at 424 nm when excited at 325 nm. The PL intensity of NGQDs with PEG increased with the volume of capping agents due to the enhancing luminescence effect of the surface functional group of polyethylene glycol. The optimal PEG amount of 2 wt% was found to improve the PL effect of NGQDs. Interestingly, the surface passivation of NGQDs with PEG enabled the NGQDs to exhibit strong PL performance across varying pH environments (from acidic to alkaline), addressing the issue of quenching of quantum dots in biological environments. Our research also focused on the ultrafast synthesis of NGQDs, where process parameters such as power value, catalyst volume, and reaction time were identified as important factors affecting NGQD luminescence. Our results showed that the optimal microwave power was 640 W, lower than that used in previous synthesis methods. Increasing the volume of catalyst promoted faster NGQD formation. The optimal reaction time was found to be 5 min, catalyst volume of 5 ml resulted in the highest PL intensity of NGQDs.

Safety and efficacy comparison of polyethylene glycol, hemp seed oil, and 5% sugar brine for bowel preparation in older patients: study protocol for a randomized controlled trial

BackgroundThe incidence of colorectal cancer among the middle-aged and elderly is gradually increasing in China. Colonoscopy is an effective method for the early diagnosis of colorectal cancer, and bowel preparation is one of many important factors affecting colonoscopy. Although there are many studies on intestinal cleansers, the results are not ideal. There is evidence that hemp seed oil has certain potential effects in intestinal cleansing, but prospective studies on this topic are still lacking.MethodsThis is a randomized, double-blind, single-center clinical study. We randomly assigned 690 participants to groups each administered 3 L of polyethylene glycol (PEG), 30 mL of hemp seed oil and 2 L of PEG, or 30 mL of hempseed oil, 2 L of PEG, and 1000 mL of 5% sugar brine. The Boston Bowel Preparation Scale was considered the primary outcome measure. We evaluated the interval between consumption of bowel preparation and first bowel movement. Secondary indicators included the time of cecal intubation, detection rate of polyps and adenomas, willingness to repeat the same bowel preparation, whether the protocol was tolerated, and whether there were adverse reactions during bowel preparation and were evaluated after counting the total number of bowel movements.DiscussionThis study aimed to test the hypothesis that hemp seed oil (30 mL) increases the quality of bowel preparation and reduces the amount of PEG. Previously, we found that its combination with 5% sugar brine can reduce the occurrence of adverse reactions.Trial registrationChinese Clinical Trial Registry ChiCTR2200057626. Prospectively registered on March 15, 2022

Fabrication and characterization of PEG-In2O3 modified PbO2 anode for electrochemical degradation of metronidazole

An In2O3-PbO2 anode with high electrocatalytic activity was prepared in our previous study. However, the service life of In2O3-PbO2 anode needed to be further improved. Thus, a typical stabilizer of polyethylene glycol (PEG) was used to modify the In2O3-PbO2 anode in this study. Theoretical and experimental results show that a small amount of PEG promoted the doping of In2O3 into β-PbO2 film, while excessive PEG reduced the doping of In2O3. Doping a moderate amount of PEG not only reduced the PbO2 crystal size, improved the density of electrode film, reduced the charge transfer resistance, increased the oxygen evolution potential, number of active sites and capacity of •OH generation of In2O3-PbO2 anode, but also prolonged the service life of In2O3-PbO2 anode from 96 to 137 h. In the process of electrochemical degradation of metronidazole, the PEG/In2O3-PbO2 anode exhibited superior electrocatalytic activity. The degradation rate constant at the PEG/In2O3-PbO2 anode was 1.682 times higher than that at In2O3-PbO2 anode. After 60 min of electrolysis, COD and TOC removals reached up to 80.92% and 78.52%, respectively, much higher than those of In2O3-PbO2 anode (69.24% and 55.83%, respectively). Additionally, a total of 13 intermediates generated in the degradation process were identified by LC-MS, and two possible degradation pathways were proposed accordingly. Overall, this study offers a promising approach for enhancing the electrocatalytic activity and stability of the PbO2 anode.

Impact of different polyethylene glycol wood treatments on the adhesive properties of beech wood

ABSTRACT Modified beech wood, treated with polyethylene glycol (PEG), was examined regarding its adhesive properties. Therefore, beech wood was modified with various molecular weights and amounts of PEG. All variants of the PEG treatment lead to an improved dimensional stability of beech wood samples. Afterwards, three different kinds of adhesive systems were tested on the modified wood. The three adhesive systems were based on phenol-resorcin-formaldehyde (PRF), emulsion-polymer-isocyanate (EPI) and melamine-urea-formaldehyde (MUF). The adhesives were tested according to a delamination test between layers (DIN EN 16351 annex A) and a determination of the longitudinal tensile bonding strength (DIN EN 302-1 A1). The achieved results showed an effective wood modification with suitable bonding properties. The usage of PEG-modified beech in constructive applications such as cross-laminated-timber (CLT) seems to be possible.

Poly(aspartic acid)-Based Polymeric Nanoparticle for Local and Systemic mRNA Delivery.

Recently, therapeutics based on mRNA (mRNA) have attracted significant interest for vaccines, cancer immunotherapy, and gene editing. However, the lack of biocompatible vehicles capable of delivering mRNA to the target tissue and efficiently expressing the encoded proteins impedes the development of mRNA-based therapies for a variety of diseases. Herein, we report mRNA-loaded polymeric nanoparticles based on diethylenetriamine-substituted poly(aspartic acid) that induce protein expression in the lungs and muscles following intravenous and intramuscular injections, respectively. Animal studies revealed that the amount of polyethylene glycol (PEG) on the nanoparticle surface affects the translation of the delivered mRNA into the encoded protein in the target tissue. After systemic administration, only mRNA-loaded nanoparticles modified with PEG at a molar ratio of 1:1 (PEG/polymer) induce protein expression in the lungs. In contrast, protein expression was detected only following intramuscular injection of mRNA-loaded nanoparticles with a PEG/polymer ratio of 10:1. These findings suggest that the PEG density on the surface of poly(aspartic acid)-based nanoparticles should be optimized for different delivery routes depending on the purpose of the mRNA treatment.

Markedly Reduced FVIII Recovery Associated with Anti-FVIII Peg Antibodies after BNT162b2 Sars-Cov-2 Vaccination

Background The covalent link of polyethylene glycol (PEG) chains to recombinant factor VIII (FVIII) molecule is one of the most established approaches to produce novel therapeutic FVIII products with extended half-life (EHL). To date, three PEGyated-FVIII molecules, rurioctocog alfa pegol, turoctocog alfa pegol, and damoctocog alfa pegol are available for treatment of hemophilia A patients. From the pivotal clinical studies data, they showed comparable safety profile and pharmacokinetic with a mean half-live 1.3-1.7 times longer than the standard non-PEGylated FVIII. Although the PEG polymer is considered non immunogenic, antibodies against PEG, called pre-existing anti-PEG antibodies (APAs), have been reported in persons never treated with PEGylated drugs owing to PEG exposure during the activities of daily living. These antibodies can impact the clinical efficacy of PEGylated drug therapies by accelerating the blood clearance and changing pharmacokinetic. Recently, small amounts of PEG are also included in the lipid nanoparticles of the mRNA SARS-Cov-2 vaccines, BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna). Aim To describe a poor plasma FVIII recovery after the first infusion of a PEGylated FVIII product in two male patients with severe hemophilia A without inhibitor at about one month from the second dose of the BNT162b2 SARS-Cov-2 vaccination. Method About two months after the first dose of the SARS-Cov-2 vaccine and one month after the second, before switching from a standard half-life to a PEGylated FVIII product, patients underwent a PK study by infusion of 50 IU/kg of turoctocog alfa pegol (patient 1) or damoctocog alfa pegol (patient 2). FVIII activity was measured by Chromogenix Coamatic FVIII (Werfen) in plasma samples collected before and after the PEGylated FVIII infusion. Anti-PEGylated FVIII antibodies were searched by means of a home-made ELISA in plasma samples collected before administration of SARS-Cov-2 vaccine and at PK study. The assay was performed by using as capturing substrates each of the licensed PEGylated FVIII product (rurioctocog alfa pegol, turoctocog alfa pegol, and damoctocog alfa). Moreover, a non-PEGylated standard FVIII (Advate®) was employed as control substrate. Results FVIII coagulant activity measured after the infusion of 50 IU/kg of the PEGylated FVIII product showed a very low plasma recovery, 5% for patient 1 and 4% for patient 2. Anti-PEGylated FVIII antibodies reacting with each PEGylated FVIII products were found in plasma samples collected at PK baseline and after FVIII infusion but not in a sample obtained before the SARS-Cov-2 vaccination. No reactivity was found in vitro against the non-PEGylated standard FVIII product (figure). Conclusions Our finding of antibodies reacting with the PEGylated part of the FVIII molecule induced or boosted by BNT162b2 SARS-Cov-2 vaccination supports the view that the administration of the mRNA vaccine could impair plasma FVIII recovery after infusion of a PEGylated product. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Low volume polyethylene glycol combined with senna versushigh volume polyethylene glycol, which regimen is better for bowel preparation for colonoscopy? A randomized, controlled, and single-blinded trial.

Background and AimsBowel preparation affects the quality of colonoscopy. Reaching the optimal preparation has been a challenge for years. Polyethylene glycol (PEG) is the sole FDA‐approved substance for this purpose. However, patients find it unpleasant and often complain about its adverse effects. In this study, we aimed to reduce these complaints by lowering the amount of PEG and adding senna which is an herbal stimulant laxative.MethodsFour hundred and eighty‐six patients were admitted for colonoscopy. Finally, 382 patients were enrolled in the study and we divided them into two groups; 186 patients were placed in which conventional high volume PEG‐alone regimen was consumed and 196 patients in which low volume PEG plus senna regimen was offered. The quality of colon preparation was compared between the two groups by independent two samples t‐test (or its corresponding nonparametric test), Fisher's exact, or χ 2 test in SPSS software version 22.ResultsThe colon preparation quality was equally efficient in the two groups as 69.36% in the high volume PEG group and 71.94% in PEG plus senna group had adequate bowel preparation (p = 0.58). Adverse effects, like nausea, bloating, headache, and sleeplessness were significantly less in the low volume PEG plus senna group.ConclusionBesides the fact that bowel preparation by low volume PEG plus senna combination was noninferior to the conventional high volume PEG‐alone regimen, the side effects were much less common with the low volume PEG plus senna regimen.

PEG Conjugated Zein Nanoparticles for In Vivo Use.

Zein can be utilized to form nanoscale particles for drug delivery applications. Despite the ease of synthesis, these particles often aggregate when exposed to physiologically relevant conditions (e.g., pH and salt concentrations). This instability has prevented their further development in applications requiring intravenous administration. To mitigate this colloidal instability, this research explored Zein nanoparticles (NP)s that were modified with polyethylene glycol (PEG) either through functionalized PEG pre- or post-NP formation. The results suggest that the pre-functionalization of the Zein using N-hydroxysuccinimide ester terminated PEG is the method of choice for synthesizing Zein NPs with conjugated PEG (Zein:PEG-Zein NPs). Zein:PEG-Zein NPs formed using this method displayed excellent stability in physiologically relevant conditions over 72 h and were stable at 4 °C for at least 3 months. When the NPs were cultured with cells for 72 h, no cytotoxicity or early signs of apoptosis were identified. Cellular uptake of the Zein:PEG-Zein NPs did not seem to be impacted by the amount of PEG incorporated in the NP but were concentration-, time-, and temperature-dependent. The lowest percent, stable Zein:PEG-Zein NP formulation (80% unmodified Zein and 20% PEG-modified Zein) induced no observable toxicity over 14 days in CD-1 mice dosed at 70 mg/kg via the tail vein. However, repeat dose pharmacokinetic (PK) studies demonstrated that following the first dose, the second dose caused health issues that required euthanasia shortly after administration. For those animals that survived, there was faster plasma elimination of the Zein:PEG-Zein NPs. Despite this, the Zein:PEG-Zein NPs represent a significantly improved formulation approach, one that displays a long circulation half-life and is suitable for single-use administration. Repeat dose applications will require additional methods to silence the immune response that is generated when using these NPs intravenously.

Anti-PEG Antibodies Boosted in Humans by SARS-CoV-2 Lipid Nanoparticle mRNA Vaccine.

Humans commonly have low level antibodies to poly(ethylene) glycol (PEG) due to environmental exposure. Lipid nanoparticle (LNP) mRNA vaccines for SARS-CoV-2 contain small amounts of PEG, but it is not known whether PEG antibodies are enhanced by vaccination and what their impact is on particle–immune cell interactions in human blood. We studied plasma from 130 adults receiving either the BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) mRNA vaccines or no SARS-CoV-2 vaccine for PEG-specific antibodies. Anti-PEG IgG was commonly detected prior to vaccination and was significantly boosted a mean of 13.1-fold (range 1.0–70.9) following mRNA-1273 vaccination and a mean of 1.78-fold (range 0.68–16.6) following BNT162b2 vaccination. Anti-PEG IgM increased 68.5-fold (range 0.9–377.1) and 2.64-fold (0.76–12.84) following mRNA-1273 and BNT162b2 vaccination, respectively. The rise in PEG-specific antibodies following mRNA-1273 vaccination was associated with a significant increase in the association of clinically relevant PEGylated LNPs with blood phagocytes ex vivo. PEG antibodies did not impact the SARS-CoV-2 specific neutralizing antibody response to vaccination. However, the elevated levels of vaccine-induced anti-PEG antibodies correlated with increased systemic reactogenicity following two doses of vaccination. We conclude that PEG-specific antibodies can be boosted by LNP mRNA vaccination and that the rise in PEG-specific antibodies is associated with systemic reactogenicity and an increase of PEG particle–leukocyte association in human blood. The longer-term clinical impact of the increase in PEG-specific antibodies induced by lipid nanoparticle mRNA vaccines should be monitored. It may be useful to identify suitable alternatives to PEG for developing next-generation LNP vaccines to overcome PEG immunogenicity in the future.

Effect of Vehicle Composition on the Preparation of Different Types of Dapsone Crystals for Topical Drug Delivery.

Topical formulations composed of API-pure crystals have been increasingly studied, especially in regards to the impact of particle size in penetration efficiency. Less attention, however, has been devoted to the solid-state properties of drugs delivered to the skin. In this study, we address the effect of formulation composition on the crystal form existing in topical products. Dapsone (DAP) gel formulations were prepared by mixing an organic solution containing DAP with an aqueous solution containing polymers and preservatives. The organic solvent was chosen as ethoxydiglycol (DEGEE), polyethylene glycol (PEG), or 1-methyl-2-pirrolidone (MPR) to assess the impact of composition on DAP crystal form. Such solvent variations resulted in different particulate matter. In terms of crystalline nature, the presence of DEGEE in formulations induced the crystallization of DAP hydrate, while PEG cocrystal and a mixture of hydrate and MPR solvate crystallized from the same amounts of PEG and MPR, respectively. Microscopic analysis of the gels showed heterogeneous particles with different characteristics. The behavior of gels after application to the skin was also tested. Interestingly, the different formulations seemed to accumulate in different regions of the skin. This could be the result of the effect of vehicle composition/excipients on the characteristics of the skin, such as hydration. The site-specific accumulation, however, was more pronounced in crystal-loaded gels as opposed to blank formulations. These results indicate that future studies should consider the effect of formulation composition on the API crystal form landscape as part of the strategies used to successfully target drug delivery to the skin.

Biodegradable gemcitabine-loaded microdevice with sustained local drug delivery and improved tumor recurrence inhibition abilities for postoperative pancreatic tumor treatment

At present, the 10-year survival rate of patients with pancreatic cancer is still less than 4%, mainly due to the high cancer recurrence rate caused by incomplete surgery and lack of effective postoperative adjuvant treatment. Systemic chemotherapy remains the only choice for patients after surgery; however, it is accompanied by off-target effects and server systemic toxicity. Herein, we proposed a biodegradable microdevice for local sustained drug delivery and postoperative pancreatic cancer treatment as an alternative and safe option. Biodegradable poly(l-lactic-co-glycolic acid) (P(L)LGA) was developed as the matrix material, gemcitabine hydrochloride (GEM·HCl) was chosen as the therapeutic drug and polyethylene glycol (PEG) was employed as the drug release-controlled regulator. Through adjusting the amount and molecular weight of PEG, the controllable degradation of matrix and the sustained release of GEM·HCl were obtained, thus overcoming the unstable drug release properties of traditional microdevices. The drug release mechanism of microdevice and the regulating action of PEG were studied in detail. More importantly, in the treatment of the postoperative recurrence model of subcutaneous pancreatic tumor in mice, the microdevice showed effective inhibition of postoperative in situ recurrences of pancreatic tumors with excellent biosafety and minimum systemic toxicity. The microdevice developed in this study provides an option for postoperative adjuvant pancreatic treatment, and greatly broadens the application prospects of traditional chemotherapy drugs.

Polyimide/phosphorene hybrid aerogel-based composite phase change materials for high-efficient solar energy capture and photothermal conversion

• We developed a new type of composite PCM for high-efficient solar energy capture. • The composite PCM was based on polyimide/phosphorene hybrid aerogel and PEG . • The introduction of phosphorene enhances solar photothermal absorption and conversion. • The composite PCM presents high solar light-to-heat conversion efficiency. • The composite PCM exhibits great potential for efficient utilization of solar energy. Solar energy is the cleanest and most abundant renewable energy source that can be utilized to displace fossil fuels and provide an effective solution for future energy shortage and climate change. Aiming at enhancing the capture efficiency of solar photothermal energy, we developed a novel type of phase-change composites based on polyimide (PI)/phosphorene (PR) hybrid aerogel and polyethylene glycol (PEG). The composites were prepared by fabricating a series of PI/PR hybrid aerogels with different loadings of PR nanosheets using freeze-drying and thermal imidization techniques, followed by vacuum impregnation of PEG as a phase change material into the aerogel framework. The obtained hybrid aerogels exhibited a lightweight nature with a density of 21.9 mg·cm −3 when 16 wt% PR nanosheets were incorporated, resulting in an extremely high PEG loading of 4067% in the aerogel system. The combination of PI and PR nanosheets leads to a significant enhancement in solar light absorption and photothermal energy conversion for the hybrid aerogel/PEG composites. The loading amount of PEG was also improved remarkably due to an increase in the volume capacity of the hybrid aerogels resulting from the introduction of PR nanosheets. The resultant hybrid aerogel/PEG composites not only exhibit a high latent-heat capacity of over 170 J·g −1 and a high photothermal conversion efficiency of 82.5%, but also show good thermal impact resistance to keep their original shape and form well after heating at 80 °C for 20 min and maintain a high thermal cycle stability after thermally cycled for 500 times. These superior performances make the hybrid aerogel/PEG composites capable of dealing with a wide range of applications in solar photothermal energy capture and storage. This study provides a promising strategy for the design and development of high-performance and lightweight composite PCMs to meet the requirement of applications for efficient utilization of solar energy.

Fixed drug eruption after Pfizer-BioNTech COVID-19 vaccine: A case report

Fixed drug eruption after Pfizer-BioNTech COVID-19 vaccine: A case report

Preparation of thyme oil loaded κ-carrageenan-polyethylene glycol hydrogel membranes as wound care system

The present study is aimed at fabricating thyme oil loaded hydrogel membranes composed of κ-carrageenan (CG) and polyethylene glycol (PEG), which can provide moist environment and prevent infections for rapid wound healing. Membranes were prepared with different amounts of PEG via solvent casting technique under ambient conditions. Physicochemical properties of CG-PEG membranes as a function of the PEG content were investigated. The surface morphology of membranes displayed smoother surfaces with increasing PEG content up to 40%. In addition, the interaction of PEG with CG polymer chains was evaluated in terms of Free and bound PEG fraction within the membrane matrix. Furthermore, thyme oil (TO) was added to enhance the antibacterial properties of CG-PEG membranes. These membranes showed >95% antimicrobial activity against both gram-positive and gram-negative bacteria depending on the TO content. Suggesting the great potential of these membranes as a strong candidate for providing an effective antimicrobial nature in human healthcare.

Improvement of the saturation magnetization of PEG coated superparamagnetic iron oxide nanoparticles

Polyethylene glycol (PEG) coated iron oxide nanoparticles are of interest because of their distinctive properties and potential applications such as magnetic resonance imaging, magnetic hyperthermia and drug delivery. In this study, PEG coated iron oxide nanoparticles were obtained by a two-step synthesis route including coprecipitation and coating. Different amounts of PEG6000 were used for coating and the effect of PEG amount on the structural and magnetic properties of the nanoparticles was investigated. Crystal structure, surface coating and particle size of the nanoparticles were characterized by X-ray diffraction technique, Fourier transform infrared spectroscopy and transmission electron microscopy. The particle size of iron oxide nanoparticles remained almost constant (7–8 nm) with the increase of PEG amount. It was determined from thermogravimetric analysis that the coating percentage of the nanoparticles steadily increased from 2.6 to 6.9 % with the increase of PEG amount from 5 to 15 g. Magnetic properties of the nanoparticles were studied by vibrating sample magnetometer and all samples were found to be superparamagnetic. PEG coated iron oxide nanoparticles showed higher saturation magnetization, Ms values than the uncoated iron oxide nanoparticles. Also, Ms of the coated nanoparticles increased with the increase of PEG coating and reached a value of 62.4 emu/g showing an increase of 19 % over uncoated iron oxide nanoparticles while maintaining the superparamagnetic behavior. This remarkable rise in the Ms of PEG coated iron oxide nanoparticles may improve the control and delivery of the nanoparticles for potential applications.