ARTICLE | doi:10.20944/preprints202308.1498.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: laccase; PEG; thermostability
Online: 22 August 2023 (07:44:09 CEST)
Laccases are versatile and relatively accessible catalysts with practical/industrial applications. Their proteic nature entails limited stability under non-native conditions, especially such as those that would be required for industrial applications. Here, derivatization of a laccase from Sclerotinia sclerotiorum is reported, using an (methyl-PEG12)3-PEG4) N-succinimide ester in order to improve the thermostability of the enzyme. The PEGylated laccase is characterized using gel electrophoresis, size-exclusion chromatography, catalytic parameters and thermal stability. A 50% increase in residual activity after incubation at 50°C for up to two hours was achieved for the PEGylated laccase compared to the native enzyme.
ARTICLE | doi:10.20944/preprints202305.0027.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: ultrafiltration; PEG; CNC; COD; turbidity; morphology
Online: 2 May 2023 (03:32:44 CEST)
This work demonstrated the potential of CNC as a substitute for PEG as an additive in ultrafiltration membrane fabrication. Two sets of modified membranes were fabricated using the phase inversion technique with polyethersulfone (PES) as the base polymer, and 1-N-methyl-2 pyrrolidone (NMP) as the solvent. The first set was fabricated with 0.075 wt% CNC, while the second set was fabricated with 2 wt% PEG. All membranes were characterized using SEM, EDX, FTIR, and contact angle measurements. The SEM images were analyzed for surface characteristics using WSxM 5.0 Develop 9.1 software. The membranes were tested, characterized, and compared for their performance in treating both synthetic turbid water and real restaurant Both membranes exhibited improved hydrophilicity, morphology, pore structure, and roughness. Both membranes also exhibited similar water flux for real and synthetic polluted water. However, the membrane prepared with CNC gave the higher turbidity removal and COD removal when raw restaurant water was treated. The membrane compared well with the UF membrane containing 2 wt% PEG in terms of morphology and performance when synthetic turbid water and raw restaurant water were treated.
ARTICLE | doi:10.20944/preprints202302.0143.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: COVID-19 vaccines; demyelinating disorders; PEG
Online: 8 February 2023 (09:55:41 CET)
Introduction: The rapid emergence of COVID-19 as a global crisis has led to the approval of many vaccinations, which were unfortunately associated with high complication rates due to a lack of sufficient safety studies. Objectives: The following manuscript focuses on discussing the demyelinating disorders that were noticed after COVID vaccine administration. Methods: We conducted a retrospective study using anonymous medical records from the US vaccine adverse events reporting system, complications retrieved included Acute disseminated encephalomyelitis (ADEM), Guillain Barre syndrome (GBS), and Multiple sclerosis (MS), outcome parameters were age, sex and the dose after which this complication was observed. Patients younger than 18 years-old were excluded as some of the vaccines, namely Janssen (JNJ-78436735) is not yet approved below this age. Results: Our analysis showed that demyelinating disorders were more likely to occur in patients over the age of 50 compared to other age groups, regardless of the type of vaccination, except for MS and ADEM occurrences after the Jansen vaccine. In addition, demyelinating complications were more likely to occur after the first dose of vaccination. Conclusion: Further research and observation of demyelinating diseases in different vaccinations, as well as additional in vitro studies, are recommended to further explain the pathogenesis of demyelinating disorder occurrence.
ARTICLE | doi:10.20944/preprints202209.0356.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: PEG; viability; osteoblasts; fibroblasts; pH; polyurethane; polyethylene glycol
Online: 23 September 2022 (03:52:52 CEST)
Grafting polyethylene glycol (PEG) on polymers surface is widely used to improve biocompatibility by reducing protein and cell adhesion. Although PEG is considered to be bioinert, its incorporation to biomaterials has shown to improve cell viability depending on the amount and molecular weight (MW) used. This phenomenon was studied here by grafting PEG of three MW onto polyurethane (PU) substrata at three molar concentrations to assess their effect on PU surface properties and on the viability of osteoblasts and fibroblasts. PEG formed a covering on the substrata which increased the hydrophilicity and surface energy of PUs. Among the results it was observed that osteoblast viability increased for all MW and grafting densities of PEG employed compared with unmodified PU. However, fibroblast viability only increased at certain combinations of MW and grafting densities of PEG, suggesting an optimal level of these parameters. PEG grafting also promoted a more spread cell morphology than that exhibited by unmodified PU; nevertheless, cells became apoptotic-like as PEG MW and grafting density were increased. These effects on cells could be due to PEG affecting culture medium pH, which became more alkaline at higher MW and concentrations of PEG. Results support the hypothesis that surface energy of PU substrates can be tuned by controlling the MW and grafting density of PEG, but these parameters should be optimized to promote cell viability without inducing apoptotic-like behavior.
ARTICLE | doi:10.20944/preprints202307.1878.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Microparticles; PEG; PLGA; coaxial flow; phase separation; drug delivery
Online: 27 July 2023 (09:38:27 CEST)
Polymeric microparticles of polyethyleneglycol-polylactic acid-co-glycolic acid (PEG-PLGA) are widely used as drug carriers for a variety of applications due to their unique characteristics. Herein, we developed a novel method for the synthesis of uniformly sized microparticles via coaxial flow-phase separation. The study evaluated the effect of various process parameters on microparticle size and polydispersity including polymer concentration, stirring rate, surfactant concentration, and the organic/aqueous phase flow rate and volume ratio. The results demonstrated that stirring rate and polymer concentration had the most significant impact on the mean particle size and distribution whereas surfactant concentration had the most substantial impact on the morphology of particles. Several microparticle formulations yielding particle sizes in the range of (5-50 µm), morphology, and concentration were synthesized as a demonstration of the tunability and scalability of this method. Notably, by controlling the process parameters microparticles of less than ~ 7 μm could be made using polymer concentrations varying by an order of magnitude. Finally, we demonstrated the tunability and scalability of this method by showing a 10-fold increase in encapsulation efficiency, a 3-fold increase in drug loading of a model hydrophilic drug, and modified release kinetics in microparticle formulations of comparable sizes but different polymer concentrations.
ARTICLE | doi:10.20944/preprints202308.1057.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: Targeted delivery; A6 peptide; PCL-PEG; Nanoparticle; Nanopolymer; Curcumin; Cancer
Online: 14 August 2023 (15:36:50 CEST)
Polymeric based nanoparticles are garnering significant interest for their potential in drug delivery. Specially, nanopolymers that have been functionalized with molecules, such as proteins or peptides, are a versatile vehicle for drug delivery. Curcumin (Cur) is one of the most commonly studied anticancer compounds and is widely acknowledged as having positive effects on human health. However, its insolubility and low bio-distribution greatly hinder the exploitation of its beneficial traits. In this study, our team created a nano delivery system which utilized a nanopolymer called PCL-PEG (poly(ε-caprolactone)-poly (ethylene glycol)). This system was functionalized with A6 peptide to enable targeted delivery of Cur. The system was designed with advantageous nanoparticles (NPs), including a stable zeta potential (–32.7), small size (54.3), uniform surface morphology, and high hydrophilicity (13.72°). In addition, targeted delivery systems exhibited high encapsulation efficacy (93 ± 0.89 %), and drug loading (16.7 ± 0.9 %), and were characterized by a slow and gradual release profile with a release of approximately 83.13 ± 0.12%. The MTT assay results showed that the formulation known as Cur-NPs-A6 caused a significant increase in cell death in MDA-MB-231 cancer cells (IC50 = 23.31 ± 0.85 µM). The designed delivery system did not cause any harm to the noncancerous MCF-10A cells (normal group). Furthermore, the results of both the RT-qPCR and invasion assays demonstrated that the designed system was able to effectively activate the apoptosis pathway and inhibit cell invasion. Our findings suggest that the use of the designed smart delivery system, which is functionalized with A6 peptide that has a high affinity for CD44 receptor - known to be upregulated in numerous malignant conditions, could be a highly efficient approach to treating cancer.
ARTICLE | doi:10.20944/preprints202210.0272.v1
Subject: Physical Sciences, Chemical Physics Keywords: polyethylene glycol; monodisperse PEG; reversed-phase chromatography; thermodynamic analysis; modelling
Online: 19 October 2022 (07:39:14 CEST)
Separation of polyethylene glycols (PEGs) into single homologs by reversed-phase chromatography is investigated experimentally and theoretically. The used core-shell column is shown to achieve baseline separation of PEG homologs up to molar weights of at least 5000 g/mol. A detailed study is performed elucidating the role of the operating conditions temperature, eluent composition, and degree of polymerization of the polymer. Applying Martin's rule yields a simple model for retention times that holds for a wide range of conditions. In combination with relations for column efficiency, the role of the operating conditions is discussed and separations are predicted for analytical-scale chromatography. Finally, the approach is included in an efficient process model based on discrete convolution, which is demonstrated to predict with high accuracy also advanced operating modes with arbitrary injection profiles.
ARTICLE | doi:10.20944/preprints202011.0620.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Super-hydrophobic; Polyethylene glycol (PEG); Hydroxyl; Stable; lauryl methacrylate (LMA)
Online: 24 November 2020 (14:43:02 CET)
In order to obtain stable super-hydrophobicity, suitable hydrophobic treatment agent should be selected according to different materials. In this paper, cotton and poly (-ethylene terephthalate) (PET) fabric was respectively coated by dodecyl methacrylate (LMA) via argon combined capacitively coupled plasma (CCP), and the surface hydrophobicity and durability of treated cotton and polyester fabrics were also discussed. An interesting phenomenon was happened that LMA coated cotton fabric (Cotton-g-LMA) had better water repellency and mechanical durability than LMA coated PET fabric (PET-g-LMA), and LMA coated hydroxyl grafted PET fabrics (PET fabrics were successively coated with polyethylene glycol (PEG) and LMA, PET-g-PEG&LMA) had similar performance to those of cotton fabrics. The water contact angle (WCA) of Cotton-g-LMA, PET-g-LMA and PET-g-PEG&LMA was 156 °, 153 ° and 155 °, respectively, and after 45 washing cycles or 1000 rubbing cycles, the corresponding WCA was decreased to 145 °, 88 °, 134 °and 146 °, 127 °, 143 °, respectively. Also, thermoplastic polyurethane (TPU) and polyamides-6 (PA6) fabrics were all exhibited the same properties to PET fabric. Therefore, the grafting of hydroxyl can improve the hydrophobic effect of LMA coating and the binding property between LMA and fabrics effectively without changing the wearing comfort..
ARTICLE | doi:10.20944/preprints202301.0351.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: X-ray luminescence; solvothermal synthesis; LaF3:Ce; Zeta-potential; PEG; PVP; PEI
Online: 19 January 2023 (09:13:37 CET)
A series of LaF3:Ce3+ phosphors for the application in photodynamic therapy is synthesized using a one-stage solvothermal synthesis. The conditions providing the maximum intensity of UV- and X-ray-excited luminescence, lowest size and highest colloidal stability of the phosphor nanoparticles are found to respectively include cerium content 5% mol., use of ethanol as the reaction medium for the solvothermal synthesis and addition of polyvinylpyrrolidone as a stabilizer in an optimized amount.
Subject: Medicine And Pharmacology, Surgery Keywords: Endovascular Aneurysm Repair; EVAR; Aortic Aneurysm; PEG; polymer; Vascular Surgery; aortic endograft.
Online: 24 February 2021 (10:00:44 CET)
An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta that progressively grows till the rupture. Treatment is typically recommended when the diameter is more than 5 cm. The EVAR (Endovascular aneurysm repair) is a mininvasive procedure that involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. For years, stent grafts' essential design was based on metallic stent frames to support the fabric. More recently, a polymer-based technology has been proposed as an alternative method to seal AAA. This review underlines the two platforms that are based on a polymer technology: 1)the polymer-filled endobags, so-called Endovascular Aneurysm Sealing (EVAS) with Nellix stent graft; and 2)the O-ring EVAR polymer-based proximal neck sealing device, so-called Ovation stent graft. Polymer characteristics for this particular aim, clinical applications, and durability results are summarized and commented critically. The platform that embraced the concept of inflating endobags filled with polymer to exclude the aneurysmal sac was not successful because of the lack of an adequate proximal fixation. The platform that used polymer to create a circumferential sealing of the aneurysmal neck has proven safe and effective.
BRIEF REPORT | doi:10.20944/preprints202311.1365.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: owel preparation; Duodenal lesions; Gastric lesions; Oral sulfate solution (OSS); polyethylene glycol (PEG)
Online: 22 November 2023 (03:39:59 CET)
Background: During esophagogastroduodenoscopy performed with colonoscopy, gastric and duodenal erythema, erosions, and ulcerations are often observed. This investigation was designed to review the prevalence of gastroduodenal lesions in patients who underwent wireless capsule endoscopy using standard bowel cleansing preparations, but no endoscopy or sedation. Methods: A retrospective analysis was conducted on patients referred for capsule endoscopy. Records and capsule reports were reviewed for patient demographics, preparation prescribed, procedural indications, and gastroduodenal findings. Preparations studied included polyethylene glycol lavage (PEG), PEG plus bisacodyl (PEG+bis), bisacodyl (bis), oral sulfate solution (OSS) and no prep. Results: Among the 1236 records, 498 (40.3%) were men and 738 (59.7%) were women. The mean age was 57 years +/- 17.8 years SD. The percentage of patients with lesions after any bowel preparation was 52.7% for gastric lesions and 23.6% for duodenal lesions. The percentage of patients with gastroduodenal lesions was 58.3% with prep, compared to 38.2% without prep. These findings were statistically significant with RR 1.53 [1.19-1.94] (p-value=0.00004). This difference was more pronounced in the OSS group RR 1.65 [1.29-2.1] and bisacodyl groups RR 1.64 [1.25-2.15] compared to the PEG group RR 0.95 [0.7-1.3]. Conclusion: This study showed that patients undergoing wireless capsule endoscopy who received bowel preparations had a significant increase in gastric and duodenal lesions. Of the preparations studied, OSS was associated with the greater number of gastroduodenal lesions, while PEG was the least associated with lesions with an occurrence similar to the non-prep group. The clinical significance of these lesions remains undetermined.
REVIEW | doi:10.20944/preprints201812.0145.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: drought stress; drought models; drought tolerance; oxidative stress; phytohormones; polyethylene glycol (PEG); stress markers
Online: 12 December 2018 (12:19:35 CET)
Drought is one of the major stress factors affecting growth and development of plants. In this context, drought-related losses of crop plant productivity impede sustainable agriculture all over the world. In general, plants responses to water deficit by multiple physiological and metabolic adaptations at the molecular, cellular and organism levels. To understand the underlying mechanisms of drought tolerance, adequate stress models and arrays of reliable stress markers are required. Therefore, in this review we comprehensively address currently available models of drought stress, based on culturing plants in soil, hydroponic or agar culture. These experimental setups give access to different aspects of plant response to drought, like decrease of tissue water potential, reduction of stomata conductance and photosynthesis efficiency, accumulation of low-molecular weight solutes (metabolic adjustment) and drought protective proteins. Till now, this pattern of markers was successfully extended to the methods of enzyme chemistry, molecular biology and omics techniques. Thus, conventional tests can be efficiently complemented by determination of phytohormone and reactive oxygen species (ROS) contents, activities of antioxidant enzymes, as well as comprehensive profiling of transcriptome, proteome and metabolome.
ARTICLE | doi:10.20944/preprints201811.0456.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: brachypodium; neutral red; root; casparian bands; PEG-6000; osmotic stress; real time imaging; PDMS
Online: 19 November 2018 (11:05:36 CET)
To elucidate dynamic developmental processes in plants, live tissues and organs have to be visualized frequently and for long time periods. The development of roots is studied in depth at a cellular resolution not only to comprehend the basic processes fundamental to maintenance and pattern formation but also study stress tolerance adaptation in plants. Despite technological advancements, maintaining continuous access to samples and simultaneously preserving their morphological structures and physiological conditions without causing damage presents hindrances in the measurement, visualization and analyses of growing organs including plant roots. We propose a preliminary system which integrates the optical real-time visualization through light microscopy with a liquid culture which enables us to image at the tissue and cellular level horizontally growing Brachypodium roots every few minutes and up to 24 hours. We describe a simple setup which can be used to track the growth of the root as it grows including the root tip growth and osmotic stress dynamics. We demonstrate the system’s capability to scale down the PEG-mediated osmotic stress analysis and collected data on gene expression under osmotic stress.
ARTICLE | doi:10.20944/preprints202105.0724.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: BODIPY-based photosensitizers; functionalized silica nanoparticles; folic acid; PEG; photodynamic therapy; HeLa cells; (photo) toxicity
Online: 31 May 2021 (09:58:40 CEST)
BODIPY dyes have recently raised attention as potential photosensitizers. In this work, commercial and novel photosensitizers (PSs) based on BODIPY chromophores (haloBODIPYs and orthogonal dimers strategically designed with intense bands in the blue, green or red region of the Visible spectra and high singlet oxygen production) were covalently linked to mesoporous silica nanoparticles (MSNs) further functionalized with PEG and folic acid (FA). MSNs of approximately 50 nm in size with different functional groups were synthesized to allow multiple alternatives of PS-PEG-FA decoration of their external surface. Different combinations varying the type of PS (commercial Rose Bengal, Thionine and Chlorine e6 or custom-made BODIPY-based), the linkage design and the length of PEG are detailed. All the nanosystems were physicochemically characterized (morphology, diameter, size distribution and PS loaded amount) and photophysically studied (absorption capacity, fluorescence efficiency, and singlet oxygen production) in suspension. For the most promising PS-PEG-FA silica nanoplatforms, the biocompatibility in dark conditions and the phototoxicity under suitable irradiation wavelengths (blue, green, or red) at regulated light doses (10-15 J/cm2) were compared with PSs free in solution in HeLa cells in vitro.
ARTICLE | doi:10.20944/preprints202308.1963.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Core-shell nanogels; nonlinear PEG; anisole; biocompatible; thermo-responsive; curcumin stability, high loading capacity; drug delivery
Online: 30 August 2023 (04:08:45 CEST)
Curcumin, a nontoxic and cheap natural medicine, has high therapeutic efficacy for many diseases including diabetes and cancers. Unfortunately, its exceedingly low water-solubility and rapid degradation in the body severely limit its bioavailability. In this work, we prepare a series of biocompatible poly(vinyl anisole)@nonlinear poly(ethylene glycol) (PVAS@PEG) core-shell nanogels with different PEG gel shell thickness to provide high water solubility, good stability, and controllable sustained release of curcumin. The PVAS nanogel core is designed to attract and store curcumin molecules for high drug loading capacity and the hydrophilic nonlinear PEG gel shell is designed to offer water dispersibility and thermo-responsive drug release. The obtained nanogels are monodispersed in spherical shape with clear core-shell morphology. The size and shell thickness of the nanogels can be easily controlled by changing the core-shell precursor feeding ratios. The optimized PVAS@PEG nanogels display a high curcumin loading capacity of 38.0 wt%. The nanogels can stabilize the curcumin from degradation at pH =7.4 and release the curcumin in response to heat in the physiologically important temperature range. The nanogels can enter cells effectively and exhibit negligible cytotoxicity to both the B16F10 and HL-7702 cells at a concentration up to 2.3 mg/mL. Such designed PVAS@PEG nanogels have a great potential to be used for delicate drug delivery.