Polyethylene Glycol Molecular Weight Research Articles

Optimizing Molecular Weight of Polyethylene Glycol as an Additive for Stabilizing Zn Metal Anode in Aqueous Electrolyte

Optimizing Molecular Weight of Polyethylene Glycol as an Additive for Stabilizing Zn Metal Anode in Aqueous Electrolyte

Polyethylene glycol regulates the pitch and liquid crystal behavior of cellulose nanocrystal-based photonic crystals

Inspired by iridescent color in natural creations, cellulose nanocrystal (CNC) photonic crystals artificially created by nanotechnology have great application prospects due to their potential to control light propagation in the linear and nonlinear regimes. One of the most important development directions of photonic crystals is the diversification of colors, usually by adjusting the pitch. However, few researchers notice the effect of polymer molecular weight and content on pitch regulation and the interaction between polymer and CNC liquid crystals. Polyethylene glycol (PEG) were used as polymers to regulate the pitch of CNC photonic crystals and investigate the changes in microstructure, crystal structure, thermal properties, and liquid crystal texture of the composites by changing the PEG content and molecular weight. Different photonic crystal construction systems show that when the molecular weight of PEG is 0.4 k, it can be filled between CNCs to regulate the pitch of photonic crystals, while when the molecular weight of PEG is 20 k, it cannot always be filled between CNCs in evaporation-induced self-assembly (EISA) process due to the depletion interaction, which cannot effectively regulate the pitch. This study reveals the relationship between PEG and CNC liquid crystals, which supports the development of photonic crystals and the pitch regulation.

Effect of a nonionic surfactant and anionic polyelectrolyte binary system on the stability of a calcium and magnesium carbonates dispersion

The effect of sodium polyacrylate, polyethylene glycol of various molecular weights, and their mixtures on the dispersion stability of calcium and magnesium carbonates was studied. It was shown that in the presence of a binary system, the light transmission of the dispersion decreases 1.2–1.5 times, the content of fine fraction particles increases by 1.1–1.3 times compared to the individual components. The stability of the dispersion of carbonates depends on the components ratio in the binary system and their molecular weight. The formation of adsorption solvated layers of polyacrylate and polyethylene glycol molecules at the interphase boundary contributes to an increase in the stability of the carbonate dispersion.

To Assess Drug Delivery System Nanocarrier at Industrial Production: Establishment of Liposomal Surface Using Physicochemical Properties

Liposomes have been reported to be useful nanocarrier, however, there are number of challenges to resolve before they can be optimized for drug delivery. Liposomes are taken up by cell in the reticuloendothelial system (RES). Polyethyleneglycol (PEG) modification on the liposomal membrane forms a fixed aqueous layer and thus prevents uptake by the RES. The physicochemical properties of liposomes that are most commonly evaluated particle size and zeta potential are not sufficient indicator of the passive targeting effect by PEG modification. In contrast, the fixed aqueous layer thickness (FALT) around liposomal surface was clear to be regulated to be the utilized action in the body. It was showed that the FALT value of PEG-modified liposomes containing doxorubicin increased with the increase in the molecular weight of PEG. Furthermore, PEG modification with a combination of high- and low- molecular weight PEGs on liposomal membranes showed in optimal results with respect to FALT and a higher antitumor effect. In addition, we designed and synthesized a novel PEG-lipid, different double arms PEG (DDA-PEG), which consisted of two PEG chains of 500 and 2000 in one molecule to develop more useful PEG-modified liposomes. DDA-PEG was found to have superior antitumor activity and was associated with the prevention of tumor metastasis. Furthermore, we sought to (-)-epigallocatechin-3-O-gallate (EGCG) functions as a target ligand of the 67-kDa laminin receptor (67LR), which is expressed on high-grade tumor cells. EGCG-PEG-modified liposome appear to have superior antitumor activity against high 67LR-expressing tumor cells, as the liposomes had dual effects.

Functionalized carbon nanostructures as temozolomide carriers: Physicochemical and biopharmaceutical characterization

In this study, temozolomide (TMZ), a drug used in the treatment of anaplastic astrocytoma and glioblastoma multiforme, was incorporated in multiwalled carbon nanotubes (MWCNTs) and hybrid carbon nanotubes with graphene (MWCNTs-G) functionalized by polyethylene glycol (PEG). The aim was to evaluate the potential of these nanocarriers for targeted delivery and sustained release of TMZ in brain tumor cells. Oxidized MWCNTs and MWCNTs-G were noncovalently functionalized with PEGs of different molecular weights and subsequently loaded with TMZ following standard procedures. Thorough physicochemical and biopharmaceutical characterization of the TMZ-loaded carbon nanocarriers pointed to high encapsulation efficacy (up to 67%) and drug loading (up to 18% out of 25% theoretical value) and homogeneous particle size distribution, with z-average (160 to 300 nm) and zeta potential (?31 to ?21 mV) of the particles adequate for crossing the blood-brain-tumor-barrier (BBTB) and entering into the tumor cells. Successful functionalization and TMZ loading were confirmed by SEM and TEM images, UV-Vis absorption, infrared and Raman spectroscopy, and TGA analyses. Sustained release of TMZ from the carbon nanocarriers was observed in vitro. The presented findings form a fundamental platform for further investigation of these formulations against different types of glioma cells and in adequate animal models.

Penicillium citrinum CFAM 521 Isolated From the Amazon Region: A Novel Source of a Fibrinolytic Enzyme.

Fibrinolytic agents are essential in treating thrombosis, playing a critical role in improving survival rates in cardiovascular diseases. Microbial fibrinolytic proteases have emerged as promising alternatives due to their affordability, specificity, lower toxicity, and reduced side effects. Consequently, the search for microorganisms capable of producing these enzymes has gained significant economic importance in the pharmaceutical industry. This study reports and characterizes a novel fibrinolytic enzyme produced by Penicillium citrinum CFAM 521, a strain isolated from the Amazon region. The enzyme was purified using a polyethylene glycol (PEG)-phosphate salt aqueous two-phase system (ATPS). The effects of PEG molecular weight, PEG concentration, and phosphate concentration on the protease partition coefficient (K) were evaluated through a 22 full factorial design. The enzyme exhibited both fibrinolytic and fibrinogenolytic activities. After partitioning in a two-phase system with 10% (w/w) PEG and 15% (w/w) sodium phosphate, the fibrinolytic proteases were predominantly retained in the salt-rich bottom phase (K = 0.33). The enzyme has a molecular weight of 34 kDa, with optimal pH and temperature at 9°C and 37°C, respectively. Inhibitory analysis confirmed that it is a serine protease, and its activity was enhanced by the addition of Mn2+. Notably, the enzyme exhibited no hemolytic activity. Therefore, P. citrinum CFAM 521 represents a novel source of fibrinolytic enzymes, highlighting its potential as an alternative for the development of thrombolytic agents.

Pal power: Demonstration of the functional association of the Helicobacter pylori flagellar motor with peptidoglycan-associated lipoprotein (Pal) and its preliminary crystallographic analysis.

The bacterial flagellar motor is a molecular nanomachine, the assembly and regulation of which requires many accessory proteins. Their identity, structure and function are often discovered through characterisation of mutants with impaired motility. Here, we demonstrate the functional association of the Helicobacter pylori peptidoglycan-associated lipoprotein (HpPal) with the flagellar motor by analysing the motility phenotype of the ∆pal mutant, and present the results of the preliminary X-ray crystallographic analysis of its globular C-terminal domain HpPal-C. Purified HpPal-C behaved as a dimer in solution. Crystals of HpPal-C were grown by the hanging drop vapour diffusion method using medium molecular weight polyethylene glycol (PEG) Smear as the precipitating agent. The crystals belong to the primitive orthorhombic space group P1 with unit cell parameters a = 50.7, b = 63.0, c = 75.1 Å. X-ray diffraction data were collected to 1.8 Å resolution on the Australian Synchrotron beamline MX2. Calculation of the Matthews coefficient (VM=2.24 Å3/Da) and molecular replacement showed that the asymmetric unit contains two protein subunits. This study is an important step towards elucidation of the non-canonical role of H. pylori Pal in the regulation, or function of, the flagellar motor.

PETR: A novel peristaltic mixed tubular bioreactor simulating human colonic conditions.

A novel bioreactor simulating human colonic conditions for in vitro cultivation of intestinal microbiota is presented. The PEristaltic mixed Tubular bioReactor (PETR) is modular designed and periodically kneaded to simulate intestinal peristalsis. The reactor is introduced, characterized from a bioprocess engineer's perspective and discussed in its ability to mimic colon conditions. PETR provides physiological temperature and appropriate anaerobic conditions, simulates intestinal peristalsis, and has a mean residence time of 32.8 ± 0.8 h comparable to the adult human colon. The single-tube design enables a time-constant and longitudinally progressive pH gradient from 5.5 to 7.0. Using a dialysis liquid containing high molecular weight polyethylene glycol, the integrated dialysis system efficiently absorbs short chain fatty acids (up to 60%) and water (on average 850 mL d-1 ). Cultivation of a typical gut bacterium (Bifidobacterium animalis) was performed to demonstrate the applicability for controlled microbiota cultivation. PETR is unique in combining simulation of the entire colon, peristaltic mixing, dialytic water and metabolite absorption, and a progressive pH gradient in a single-tube design. PETR is a further step to precise replication of colonic conditions in vitro for reliable and reproducible microbiota research, such as studying the effect of food compounds, prebiotics or probiotics, or the development and treatment of infections with enteric pathogens, but also for further medical applications such as drug delivery studies or to study the effect of drugs on and their degradation by the microbiota.

A high performance, stable anion exchange membrane for alkaline redox flow batteries

The development of cost-effective, safe, and low-corrosion alkaline aqueous redox flow batteries, such as alkaline zinc-iron flow batteries, has motivated the research of hydrocarbon-based anion exchange membranes. These membranes, characterized by their positively charged functional groups, facilitate the transport of hydroxide anions (OH−) in alkaline environments, rendering them as potential alternatives to conventional proton exchange membranes in emerging alkaline redox flow batteries. Herein, a facilely synthesized anion exchange membrane (AEM) with superior chemical stability in alkaline media and outstanding ion conductivity has been developed for use in an alkaline redox flow battery. The membrane consists of a partially imidazolium substituted poly (vinylbenzyl chloride) polymer matrix and low molecular weight polyethylene glycol (PEG) additive. The membrane provides positively charged polymer backbone with hydroxide anion as counter ions. The additive PEG not only augments membrane flexibility through interaction with the rigid polymer backbone, but also enhances the conductivity through conducting ions by the alkalized-ether functionality. The optimized anion exchange membrane demonstrates better ionic conductivity of 58.2 mS cm−1 and comparable permeability compared with commercially Nafion117 membrane, enabling promoted energy efficiency (83.5 %), coulombic efficiency (99.85 %) and excellent stability (280 cycles with negligible capacity degradation) of a zinc-iron flow battery at 80 mA cm−2.

Mechanical properties of polymer networks with polyrotaxane crosslinkers with different molecular structures based on polyethylene glycol and α-cyclodextrin

The modification of vinyl groups on polyrotaxane derivatives, obtained with polyethylene glycol as the axial molecule and α-cyclodextrin as the cyclic molecule, allows the production of crosslinkers that react with various monomers, facilitating the formation of polymer networks. In contrast to conventional polymer crosslinked networks using typical crosslinking agents, polymer networks employing polyrotaxane crosslinking agents allow for mobile crosslinking points. Consequently, the resulting polymeric crosslinked network may exhibit increased toughness, as external stress is uniformly distributed throughout the polymeric network. This distribution helps to avoid excessive stress concentration in specific areas. To optimize the mechanical properties of polymer networks formed using polyrotaxane crosslinkers, we investigated the impact of the molecular weight of the axial molecules and the number of crosslinking points of the cyclic molecules in the polyrotaxane crosslinkers on the mechanical properties of the resulting polymer networks. Our results show that the fracture strain, fracture stress, and fracture energy of the resultant polymer networks increase with increasing molecular weight of polyethylene glycol. We also observed that the fracture stress and toughness of the polymer networks increased when there was less than one modified vinyl group on α-cyclodextrin, compared to the case with multiple vinyl groups.

Non-destructive covalent surface alkylation of graphitic carbon nitride for enhanced photocatalytic dye degradation in water

Graphitic carbon nitride (g-CN) is a promising material for various applications due to its unique electronic, optical, and photocatalytic properties, tunable by surface modifications. Herein, a novel and straightforward approach to the covalent addition of low molecular weight polyethylene glycol (PEG550) to g-CNs surface following non-destructive chemistry benefiting from simultaneous activation of hydroxyl and free-amine surface groups by a weak base, potassium carbonate, is for the first time described. The resulting g-CN-PEG550 exhibits almost two-fold enhanced water solubility due to 1 PEG550 chain addition for every ∼ 128 g-CN atoms, detected by thermogravimetric analysis. Complementary X-ray photoelectron spectroscopy elemental analysis of the isolated g-CN-PEG550 displays an increased C─O chemical environment attributed to the covalent addition of carbon- and oxygen-rich PEG550 to the g-CN surface. The g-CN-PEG550 photocatalyst performs 2.5-fold better in degrading rhodamine B due to its enhanced light absorption, improved water-dispersibility, and the efficient separation of photogenerated electron-hole pairs compared to the as-prepared g-CN. The study underscores the potential use of covalently PEGylated oxygen-rich g-CNs in photocatalytic applications.

Prolactin Monomeric Polyethylene Glycol Measurement Method and Study of Reference Value Verification

Purpose: Prolactin in the blood is separated into three types, and over 90% of prolactin presents as a double monomer (23 KDa). Rarely, it can exist in the size of big prolactin (150 KDa), which is called macroprolactin and is known as an autoantibody complex. When macroprolactin accounts for more than 60% of prolactin in the blood, it is called macroprolactinemia. The presence of such macroprolactin was first reported in a patient with hyperprolactinemia but without typical symptoms. Macroprolactinemia is emerging as an important cause of idiopathic hyperprolactinemia. The polyethylene glycol (PEG) precipitation method using the property of precipitating large-molecular-weight proteins is simple and recently has been widely used as a screening test. The results are in good agreement with the results of gel chromatography. The purpose of this study was to confirm the measurement method and reference value verification of monomeric prolactin in blood prolactin using the PEG precipitation method. Materials and Methods: For 40 examinees who visited the Gangnam Center of Seoul National University Hospital in 2021, the prolactin level was verified using radioimmunoassay (RIA). For macroprolactinemia PEG precipitation method, 25% PEG (molecular weight 6000kDa) solution and serum were mixed in equal amounts in a test tube, then left at room temperature for 20 minutes and centrifuged at 4℃ for 30 minutes (1500g). The prolactin level was measured in the supernatant. Results : After confirming that more than 90% of the 40 tested samples within the reference range <25 ng/mL, the same value as the reference value for prolactin was applied. Since the concentration of monomeric prolactin in serum from which macroprolactin has been removed from blood is diluted 1:1 with PEG, our laboratory is currently reporting the result by multiplying the result by a dilution factor of 2. Conclusion: Radioimmunoassay using PEG precipitation method using the property of precipitating large molecular weight proteins is simple and effective for quantitative measurement of monomeric prolactin in blood prolactin.

Water-soluble and Water-dispersible Polymers Used in Commercial Agricultural Formulations: Inventory of Polymers and Perspective on their Environmental Fate.

Agricultural formulations contain water-soluble and water-dispersible polymers (WSPs and WDPs) to increase the application efficiency of the active ingredients (e.g. pesticides and fertilizers). Despite their direct release to soils and crops, there is currently no inventory of used polymers and their fate in soils is poorly studied and understood. Herein, we identify WSPs and WDPs used in agricultural formulations on the German and Swiss markets. By searching the scientific literature, patents, and manufacturer websites, we tentatively identified that 233 of the 1815 listed trade names of formulation additives contained polymers, the majority of which belonged to three main chemical classes: polyethylene glycol (PEG)-based (co)polymers, functionalized polysaccharides (PSacs), and vinylic (co)polymers (VCPs). We report information on their functionalization, molecular weights, and market significance. In 2015, their estimated combined annual application volume in Switzerland surpassed 100 tonnes. Low molecular weight PEGs and natural, unfunctionalized PSacs reportedly biodegrade, suggesting no accumulation in soils associated with their use as formulation additives. Conversely, high molecular weight functionalized PEGs, functionalized PSacs, and the majority of the VCPs have been reported to undergo only slow or no soil biodegradation. These polymers may thus persist and accumulate in agricultural soils, requiring more detailed investigations of their environmental fate and resulting exposure scenarios. There is a need for systematic studies on the effects of polymer structure, molecular weight, and functionalization on soil biodegradability.

Unraveling the cytotoxicity and cellular uptake of low, medium and high molecular weight polyethylene glycol polymers in MCF-7 cells by green UPLC-MS/MS methods

Unraveling the cytotoxicity and cellular uptake of low, medium and high molecular weight polyethylene glycol (PEG) in cells is important for evaluation of therapeutic efficacy and toxicity of PEGylated drug delivery systems. In this study, cellular uptake of PEG600, PEG2K, PEG4K and PEG10K in MCF-7 cells was first studied by an UPLC-MS/MS assay coupled with collision induced dissociation (CID) in source technique. The CID of PEG in source with high values of declustering potentials generates numerous PEG-related product ions. These PEG-related fragment ions can be further broken into specific product ions in the collision cell as alternative ions for detection of PEG. The quantification of PEG was finally performed with the MRM transition (m/z 221.0 → 89.0). The experimental results indicated that the toxicity of PEG600, PEG2K, PEG4K and PEG10K was not significant at concentrations of 5–1200 μg/mL and the amounts of PEG polymers entry into MCF-7 cells at was small. The greenness of the developed analytical methods was also assessed by Analytical Eco-Scale, Analytical Greenness calculator (AGREE) and Green Analytical Procedure Index (GAPI) in this study.

Effects of molecular weight of polyethylene glycol with size and ratio of fumed silica on rheological behavior of shear thickening fluid

The rheological models of shear thickening fluids (STFs), which have recently been used in many fields, are estimated using a statistical method in this study. Although research has been carried out to predict the rheological properties of STFs, the variation of the basic parameters affecting the rheological properties has not been studied much in these estimations. To produce shear thickening fluids, silica nanoparticles have been dispersed in polyethylene glycol (PEG). To make the rheological model estimation correctly, nanoparticle ratios (10 wt%, 15 wt%, 20 wt%, 25 wt%), the particle sizes (9 nm, 12 nm, and 14 nm), and the molecular weight of the liquid mediums are produced by changing three different sample set is used. At high shear rates, mixtures of fumed silica (aerosil) and PEG display shear thickening behavior. In the low shear rates (0-200 s-1), this mixture exhibits shear thinning property, while in the high shear rates (200-1000 s-1), shear thickening behavior. Fumed silica-PEG suspensions show pseudoplastic behavior in the first region and dilatant properties in the second region. Equations from theory are used to model the outcomes of the experimental data. Non-Newtonian models are used, and the best model is chosen based on the rheological behavior of the mixes. Herschel-Bulkley is discovered to be the most suitable non-Newtonian model in the first and second regions.

Self-assembly of eugenol-loaded particles to regulate the adhesion of carriers on leaves for efficient foliar applications and ecotoxicological safety

Currently, there is a pressing need to develop an agrochemical-loaded system that is both uncomplicated and efficient, thereby enhancing the adhesion of agrochemical to leaf surfaces and optimizing their insecticidal efficacy, while concurrently mitigating environmental risks. The flexible eugenol-loaded particles were synthesized via a one-step polyurethane self-assembly reaction, utilizing polyethylene glycol (PEG) as the soft segment and 4,4-diphenylmethane diisocyanate (MDI) as the hard segment. The increase in the length of the soft segment enhances the flexibility of the particles, thereby improving the contact area and adhesion with the foliar surface. When flexible particles are applied on the foliar surface, they can achieve satisfactory resistance to rainfall erosion. When the PEG molecular weight is 800, the residual concentration of eugenol can still reach 42.11% after 6 washes. The carrier protects the active ingredients and improves the resistance to ultraviolet irradiation. After 5 h of ultraviolet irradiation, the concentration of eugenol remained at 59.03% when PEG with a molecular weight of 200 was employed. Greenhouse experiments showed that the flexible transformation of particles greatly enhanced the application effect of spray on the foliar surface of particles. After undergoing three washes, the mortality of the particles can be enhanced by 5.4–8.4 times compared to that of emulsion concentrate (EC) sample. The enhancement of leaf retention performance reduces environmental risks caused by pesticide loss. Meanwhile, the controlled release of particles also reduces the acute toxicity to zebrafish. The toxicity selection pressure of the EUG@P800-Ps sample is 10.6 times that of the EC sample. In conclusion, the preparation process of the system is simple, and the flexible transformation is an effective strategy to improve the foliar application effect of spray and improve the environmental safety.

Enrichment and separation of recombinant adeno-associated virus particles by aqueous two-phase extraction

The adeno-associated virus (AAV) has been widely employed as a popular gene therapy vector. However, current methods for its separation and purification exhibit numerous limitations. In this study, polyethylene glycol (PEG)/salt aqueous two-phase system (ATPS) was utilized as an efficient and environmentally-benign approach to separate AAV. The separation efficiency of AAV particles from other cellular components was investigated using various ATPS compositions. The effects of PEG molecular weight, types of phase-forming salts, and concentrations of different components were tested and compared. The optimal separation conditions were determined to be 17 % (w/w) PEG 600, 16 % (w/w) sodium citrate, and 15 % (w/w) crude cell lysate. The AAV particles were predominantly enriched in the interphase, while the impurities were observed in the top and bottom phases. High AAV recovery (>99 %) and efficient impurity removal (>95 %) were achieved. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transmission electron microscopy were used to characterize and verify the separated AAV particles. The results indicated that aqueous two-phase extraction possesses a robust capability for the enrichment and separation of AAV particles directly from crude cell lysates, and it shows promising potential for the separation of other viral particles.

Cellulose Acetate/Polyethylene Glycol Composite Beads for Efficient Removal of Methylene Blue

The development of eco-friendly and biodegradable adsorbent with excellent adsorption performance is of great importance for the efficient dye removal in wastewater. Herein, an efficient and biodegradable composite adsorbent bead was fabricated from cellulose acetate (CA) modified with low molecular weight polyethylene glycol 200 (PEG200) for the adsorptive removal of methylene blue dye (MB) from aqueous solution. The weight fraction of PEG was varied to investigate the effect of material bead composition on the morphology, molecular structure, crystal phases, thermal stability, mechanical properties, and adsorption performance of the composite beads. Batch adsorption was carried out at various times to estimate the time at equilibrium adsorption capacity and kinetic model. Various operating conditions such as pH, initial MB concentration, and adsorbent dosage in experiment were also executed to examine the adsorption performance of this system. The result showed that all beads have porous structure and the pore size increase after the addition of PEG200. The adsorption capacity and % MB removal generally showed an improvement with the rise of PEG content. The batch adsorption experiments demonstrated that the best % removal and adsorption capacity of MB were 93.35 % and 28.005 mg/g, respectively, that was obtained by composite CA/PEG200 (80/20) bead at pH of 11, initial MB concentration of 30 mg/L, and bead dosage of 1 g/L. The adsorption kinetic fitted well to Elovich-kinetic model with average R2 of 0.844. Overall, this work offers new finding into the development of effective, environmentally friendly, and inexpensive cellulose-based adsorbents for wastewater remediation.

Polyethylene glycol-grafted graphene oxide nanosheets in tailoring the structure and reverse osmosis performance of thin film composite membrane

Introducing hydrophilic polymers such as polyethylene glycol (PEG) within the polyamide (PA) layer of thin film composite (TFC) membranes helps achieve high water desalination performance. Here, PEGs of different molecular weights (X: 1500, 6000, 16,000 g/mol) are effectively introduced into the PA layer of TFC membranes utilizing PEG-grafted graphene oxide (GOPX) nanosheets and their effects on the physicochemical properties and reverse osmosis (RO) performance of the thin film nanocomposite (TFN) membranes are investigated. Among the TFNs prepared the GOP16000/TFN exhibits the best performance with 68% improvement in water flux and almost constant salt rejection compared to those of the bare TFC. The influence of PEG molecular weight on the RO performance of the membranes is interpreted by different surface and bulk hydrophilicity as well as thickness and surface roughness of PA layers of GOPX/TFNs. Furthermore, TFNs with thinner and smoother PA layers and thus higher water flux are obtained by dispersing GOPXs in the aqueous phase of the PA interfacial polymerization reaction than by dispersing them in the organic phase of the reaction. Finally, the high antifouling potential of TFNs containing PEG-grafted GOs is demonstrated.

Endotyping of IgE-Mediated Polyethylene Glycol and/or Polysorbate 80 Allergy.

Polyethylene glycol (PEG) and polysorbate 80 (PS80) allergy preclude from SARS-CoV-2 vaccination. The mechanism(s) governing cross-reactivity and PEG molecular weight dependence remain unclear. To evaluate PEGylated lipid nanoparticle (LNP) vaccine (BNT162b2) tolerance and explore the mechanism of reactivity in PEG and/or PS80 allergic patients. PEG/PS80 dual- (n= 3), PEG mono- (n= 7), and PS80 mono-allergic patients (n= 2) were included. Tolerability of graded vaccine challenges was assessed. Basophil activation testing on whole blood (wb-BAT) or passively sensitized donor basophils (allo-BAT) was performed using PEG, PS80, BNT162b2, and PEGylated lipids (ALC-0159). Serum PEG-specific IgE was measured in patients (n= 10) and controls (n= 15). Graded BNT162b2 challenge in dual- and PEG mono-allergic patients (n= 3/group) was well tolerated and induced anti-spike IgG seroconversion. PS80 mono-allergic patients (n= 2/2) tolerated single-dose BNT162b2 vaccination. Wb-BAT reactivity to PEG-containing antigens was observed in dual- (n= 3/3) and PEG mono- (n= 2/3), but absent in PS80 mono-allergic patients (n= 0/2). BNT162b2 elicited the highest invitro reactivity. BNT162b2 reactivity was IgE mediated, complement independent, and inhibited in allo-BAT by preincubation with short PEG motifs, or detergent-induced LNP degradation. PEG-specific IgE was only detectable in dual-allergic (n= 3/3) and PEG mono-allergic (n= 1/6) serum. PEG and PS80 cross-reactivity is determined by IgE recognizing short PEG motifs, whereas PS80 mono-allergy is PEG-independent. PS80 skin test positivity in PEG allergics was associated with a severe and persistent phenotype, higher serum PEG-specific IgE levels, and enhanced BAT reactivity. Spherical PEG exposure via LNP enhances BAT sensitivity through increased avidity. All PEG and/or PS80 excipient allergic patients can safely receive SARS-CoV-2 vaccines.