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International Journal of Molecular... Jan 2022Pseudopolyrotaxanes (PPRs) are supramolecular structures consisting of macrocycles able to thread on a linear polymer chain in a reversible, non-covalent way, often...
Pseudopolyrotaxanes (PPRs) are supramolecular structures consisting of macrocycles able to thread on a linear polymer chain in a reversible, non-covalent way, often referred to in the literature as "molecular necklaces". While the synthesis and reaction mechanisms of these structures in solution have been widely described, their solvent-free production has received little attention, despite the advantages that this route may offer. We propose in this work a kinetic mechanism that describes the PPR formation in the solid phase as a process occurring in two consecutive stages. This mechanism has been used to investigate the spontaneous formation of a PPR that occurs when grinding α-Cyclodextrin (α-CD) with polyethylene glycol (PEG). In the threading stage, the inclusion of the polymer and subsequent release of the water molecules lodged in the cavity of the macrocycle cause vibrational changes that are reflected in the time-dependence of the FTIR-ATR spectra, while the further assembly of PPRs to form crystals produces characteristic reflections in the XRD patterns, due to the channel-like arrangement of CDs, that can be used to track the formation of the adduct in crystalline form. The effects that working variables have on the kinetics of the reaction, such as temperature, feed ratio, molar mass of the polymer and the introduction of an amorphous block in the polymer structure, have been investigated. The rate constants of the threading step increase with the temperature and the activation energy of the process increases at lower proportions of CD to PEG. This is attributed to the lower degree of covering of the polymer chain with CDs that reduces the hydrogen-bonding driven stabilization between adjacent macrocycles. The formation of crystalline PPR, which takes place slowly at room temperature, is markedly promoted at higher temperatures, with lower proportions of CD favoring both the formation and the growth of the crystals. The molar mass of the polymer does not modify the typical channel-like arrangement of packed PPRs but the conversion into crystalline PPR diminishes when using PEG1000 instead of PEG400. At a microscopic level, the crystals arrange into lamellar structures, in the order of hundreds of nm, embedded in an amorphous-like matrix. The introduction of a polypropylene oxide block in the structure of the polymer (Pluronic L62) renders poorer yields and a considerable loss of crystallinity of the product of the reaction. The methodology here proposed can be applied to the general case of inclusion complexes of CDs with drugs in the solid phase, or to multicomponent systems that contain polymers as excipients in pharmaceutical formulations along with CDs.
Topics: Crystallization; Cyclodextrins; Kinetics; Poloxamer; Polyethylene Glycols; Rotaxanes; Solvents; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction; alpha-Cyclodextrins
PubMed: 35054867
DOI: 10.3390/ijms23020685 -
Revista Espanola de Enfermedades... Dec 2016The objective of this study was to evaluate in an analytical and descriptive manner the evidence published so far on the use of polyethylene glycol (PEG), with or... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The objective of this study was to evaluate in an analytical and descriptive manner the evidence published so far on the use of polyethylene glycol (PEG), with or without electrolytes, in the management of functional constipation and the treatment of fecal impaction.
METHODOLOGY
Search on MEDLINE, EMBASE and Cochrane databases until May 2016 of all publications adjusted to the following terms: constipation AND/OR fecal impaction AND (PEG OR polyethylene glycol OR macrogol OR movicol OR idralax OR miralax OR transipeg OR forlax OR golytely OR isocolan OR mulytely) NOT colonoscopy. Critical reading of selected articles (English or Spanish), sorting their description according to group age (adult/pediatric age) and within those, in accordance with study features (efficacy evaluation versus placebo, doses query, safety, comparison with other laxatives, observational studies and monographic review articles of polyethylene glycol or meta-analysis).
RESULTS
Fifty-eight publications have been chosen for descriptive analysis; of them, 41 are clinical trials, eight are observational studies and nine are systematic reviews or meta-analysis. Twelve clinical trials evaluate PEG efficacy versus placebo, eight versus lactulose, six are dose studies, five compare polyethylene glycol with and without electrolytes, two compare its efficacy with respect to milk of magnesia, and the rest of the trials evaluate polyethylene glycol with enemas (two), psyllium (one), tegaserod (one), prucalopride (one), paraffin oil (one), fiber combinations (one) and Descurainia sophia (one).
CONCLUSIONS
Polyethylene glycol with or without electrolytes is more efficacious than placebo for the treatment of functional constipation, either in adults or in pediatric patients, with great safety and tolerability. These preparations constitute the most efficacious osmotic laxatives (more than lactulose) and are the first-line treatment for functional constipation in the short and long-term. They are as efficacious as enemas in fecal impaction, avoid the need for hospital admission and are well tolerated by patients (mainly when administered without electrolytes).
Topics: Adult; Child; Constipation; Fecal Impaction; Humans; Laxatives; Polyethylene Glycols
PubMed: 27871178
DOI: 10.17235/reed.2016.4571/2016 -
Folia Medica Cracoviensia Dec 2021The need for mass population vaccination against Covid-19 poses a public health problem. Allergic symptoms occurring after the 1st dose of the vaccine may result in...
The need for mass population vaccination against Covid-19 poses a public health problem. Allergic symptoms occurring after the 1st dose of the vaccine may result in resignation from the administration of the 2nd dose. However, the majority of patients with mild and/or non-immediate symptoms may be safely vaccinated. The only absolute contraindication to administration of the vaccine is an anaphylactic reaction to any of its ingredients. Polyethylene glycol (PEG), widely used as an excipient in various vaccines, is considered the primary cause of allergic reactions associated with administration of Comirnaty (Pfizer/BioNTech) and Covid-19 Vaccine (Moderna) vaccines. However, hypersensitivity to PEG reported to date seems very rare, considering its widespread use in multiple everyday products, including medicines and cosmetics. In the paper, current literature data describing mechanisms of hypersensitivity reactions to PEG, their clinical symptoms and diagnostic capabilities are presented. Undoubtedly, the issue of hypersensitivity to PEG warrants further research, while patients with the diagnosis require individual diagnostic and therapeutic approach.
Topics: Anaphylaxis; COVID-19; COVID-19 Vaccines; Humans; Hypersensitivity; Polyethylene Glycols; SARS-CoV-2
PubMed: 35180202
DOI: 10.24425/fmc.2021.140004 -
Scientific Reports Mar 2021One of the significant proteins that have attracted research groups due to virtue of being a potent selective anticancer drug target and property of triggering apoptosis...
One of the significant proteins that have attracted research groups due to virtue of being a potent selective anticancer drug target and property of triggering apoptosis upon release in cytoplasm is cytochrome c (cyt c). The mechanical transformations due to the macromolecular crowding in membrane in the mammalian cell are proposed to be useful inductors of changes in volume. It is very interesting to know that mitochondrial function were observed to be improved by polyethylene glycol (PEG) interaction, which in turn inhibits the cyt c (a pro-apoptotic cell death factor). In this work, the effect of polyethylene glycol of molecular weight 4 kilo Dalton (PEG 4 kDa) was investigated to highlight the structural transformations (tertiary and secondary structure) in cyt c using a choice of spectroscopic techniques (including UV-Vis absorption, near-UV, far-UV and Soret circular dichroism and fluorescence spectroscopy), which shows noteworthy shifts in the secondary and tertiary structures at higher concentrations of PEG 4 kDa with small changes in the heme-globular interactions. The size distribution changes of native protein treated with various concentrations of the crowder were observed and analyzed by dynamic light scattering (DLS). The interaction studies of the crowder with the protein was observed and analyzed by FTIR, isothermal titration calorimetry, time resolved fluorescence and molecular docking. The investigations suggested that the structural changes in the protein occurred due to soft interactions of PEG 4 kDa, which usually destabilizes proteins. The experimental evidence in this study proposed that crowding could be another approach to mechanical super-competition and free of certain markers that could aid in the identification and control of various diseases. This study suggests that crowders at specific concentrations, which softly interact with proteins, can be exploited as remedy for various diseases.
Topics: Animals; Cytochromes c; Horses; Molecular Docking Simulation; Polyethylene Glycols; Protein Conformation; Protein Stability
PubMed: 33742055
DOI: 10.1038/s41598-021-85792-4 -
Advanced Science (Weinheim,... Nov 2022A chitosan composite with a vertical array of pore channels is fabricated via an electrophoretic deposition (EPD) technique. The composite consists of chitosan and...
A chitosan composite with a vertical array of pore channels is fabricated via an electrophoretic deposition (EPD) technique. The composite consists of chitosan and polyethylene glycol, as well as nanoparticles of silver oxide and silver. The formation of hydrogen bubbles during EPD renders a localized increase of hydroxyl ions that engenders the precipitation of chitosan. In addition, chemical interactions among the constituents facilitate the establishment of vertical channels occupied by hydrogen bubbles that leads to the unique honeycomb-like microstructure; a composite with a porosity of 84%, channel diameter of 488 µm, and channel length of 2 mm. The chitosan composite demonstrates an impressive water uptake of 2100% and a two-stage slow release of silver. In mass transport analysis, both Disperse Red 13 and ZnO powders show a much enhanced transport rate over that of commercial gauze. Due to its excellent structural integrity and channel independence, the chitosan composite is evaluated in a passive suction mode for an adhesive force of 9.8 N (0.56 N cm ). The chitosan composite is flexible and is able to maintain sufficient adhesive force toward objects with different surface curvatures.
Topics: Chitosan; Electrophoresis; Porosity; Polyethylene Glycols; Hydrogen
PubMed: 36180403
DOI: 10.1002/advs.202203948 -
BMC Gastroenterology Mar 2016Polyethylene glycol is commonly used to manage constipation and is available with or without electrolytes. The addition of electrolytes dates back to its initial... (Comparative Study)
Comparative Study Meta-Analysis Review
BACKGROUND
Polyethylene glycol is commonly used to manage constipation and is available with or without electrolytes. The addition of electrolytes dates back to its initial development as lavage solutions in preparation for gastrointestinal interventions. The clinical utility of the addition of electrolytes to polyethylene glycol for the management of constipation is not established. The objective of this systematic review and network meta-analysis (NMA) was to assess the relative effectiveness of polyethylene glycol with (PEG + E) or without electrolytes (PEG) in the management of functional constipation in adults.
METHODS
A systematic review was conducted to identify randomised controlled clinical trials that assessed the use of polyethylene glycol in functional constipation. The primary outcome was the mean number of bowel movements per week.
RESULTS
Nineteen studies were included in the NMA (PEG N = 9, PEG + E N = 8, PEG versus PEG + E N = 2; involving 2247 patients). PEG and PEG + E are both effective, increasing the number of bowel movements per week by 1.8 (95 % Crl 1.0, 2.8) and 1.9 (95 % Crl 0.9, 3.0) respectively versus placebo and by 1.8 (95 % Crl 0.0, 3.5) and 1.9 (95 % Crl 0.2, 3.6) respectively versus lactulose. There was no efficacy difference between PEG + E and PEG (0.1, 95 % Crl -1.1, 1.2) and there were no differences in safety or tolerability.
CONCLUSIONS
Polyethylene glycol with and without electrolytes are effective and safe treatments for constipation in adults. The addition of electrolytes to polyethylene glycol does not appear to offer any clinical benefits over polyethylene glycol alone in the management of constipation.
Topics: Constipation; Electrolytes; Humans; Polyethylene Glycols; Surface-Active Agents; Treatment Outcome
PubMed: 27029340
DOI: 10.1186/s12876-016-0457-9 -
BMC Gastroenterology Jun 2022Most microbiota studies in microscopic colitis patients are performed after diagnostic colonoscopy without considering the potential effect of colonic lavage. Patients...
Colonic bacterial diversity and dysbiosis in active microscopic colitis as compared to chronic diarrhoea and healthy controls: effect of polyethylene glycol after bowel lavage for colonoscopy.
BACKGROUND
Most microbiota studies in microscopic colitis patients are performed after diagnostic colonoscopy without considering the potential effect of colonic lavage. Patients may achieve clinical remission after colonoscopy and it is unknown whether lavage-induced changes play a role.
AIM
To assess the effect of polyethylene glycol (PEG) colonic lavage on clinical remission rate, microbial diversity, microbial dysbiosis index and specific microbial changes in patients with active microscopic colitis as compared to other diarrhoeal diseases and healthy controls.
METHODS
Fifty-five consecutive patients presenting chronic watery diarrhoea and 12 healthy controls were included. Faecal samples were collected three days before and 30 days after PEG in patients and controls for microbiome analysis.
RESULTS
Clinical remission was observed in 53% of microscopic colitis patients, and in 32% of non-microscopic colitis patients (p = 0.16). Considering patients with persisting diarrhoea after colonoscopy, 71% of non-microscopic colitis patients had bile acid diarrhoea. Baseline Shannon Index was lower in diarrhoea groups than in healthy controls (p = 0.0025); there were no differences between microscopic colitis, bile-acid diarrhoea and functional diarrhoea. The microbial dysbiosis index was significantly higher in microscopic colitis than in bile acid diarrhoea plus functional diarrhoea (p = 0.0095), but no bacterial species showed a significantly different relative abundance among the diarrheal groups.
CONCLUSIONS
Dysbiosis is a feature in active microscopic colitis, but loss of microbial diversity was similar in all diarrheal groups, suggesting that faecal microbial changes are not due to microscopic colitis itself but associated with stool form. A considerable number of microscopic colitis patients achieved clinical remission after colonoscopy, but we were unable to demonstrate related PEG-induced changes in faecal microbiome.
Topics: Bile Acids and Salts; Colitis, Microscopic; Colonoscopy; Diarrhea; Dysbiosis; Humans; Polyethylene Glycols; Therapeutic Irrigation
PubMed: 35764931
DOI: 10.1186/s12876-022-02392-w -
Tissue Engineering. Part A May 2018Off-the-shelf availability in large quantities, drug delivery functionality, and modifiable chemistry and mechanical properties make synthetic polymers highly suitable...
Off-the-shelf availability in large quantities, drug delivery functionality, and modifiable chemistry and mechanical properties make synthetic polymers highly suitable candidates for bone grafting. However, most synthetic polymers lack the ability to support cell attachment, proliferation, migration, and differentiation, and ultimately tissue formation. Incorporating anionic peptides into the polymer that mimics acidic proteins, which contribute to biomineralization and cellular attachment, could enhance bone formation. Therefore, this study investigates the effect of a phosphate functional group on osteoconductivity and BMP-2-induced bone formation in an injectable and biodegradable oligo[(polyethylene glycol) fumarate] (OPF) hydrogel. Three types of OPF hydrogels were fabricated using 0%, 20%, or 40% Bis(2-(methacryloyloxy)ethyl) phosphate creating unmodified OPF-noBP and phosphate-modified OPF-BP20 and OPF-BP40, respectively. To account for the osteoinductive effect of various BMP-2 release profiles, two different release profiles (i.e., different ratios of burst and sustained release) were obtained by varying the BMP-2 loading method. To investigate the osteoconductive effect of phosphate modification, unloaded OPF composites were assessed for bone formation in a bone defect model after 3, 6, and 9 weeks. To determine the effect of the hydrogel phosphate modification on BMP-2-induced bone formation, BMP-2 loaded OPF composites with differential BMP-2 release were analyzed after 9 weeks of subcutaneous implantation in rats. The phosphate-modified OPF hydrogels (OPF-BP20 and OPF-BP40) generated significantly more bone in an orthotopic defect compared to the unmodified hydrogel (OPF-noBP). Furthermore, the phosphate functionalized surface-enhanced BMP-2-induced ectopic bone formation regardless of the BMP-2 release profile. In conclusion, this study clearly shows that phosphate functional groups improve the osteoconductive properties of OPF and enhanced BMP-2-induced bone formation. Therefore, functionalizing hydrogels with phosphate groups by crosslinking monomers into the hydrogel matrix could provide a valuable method for improving polymer characteristics and holds great promise for bone tissue engineering.
Topics: Animals; Bone Morphogenetic Protein 2; Bone Regeneration; Microscopy, Electron, Scanning; Microspheres; Osteogenesis; Phosphates; Polyethylene Glycols; Rats
PubMed: 29065776
DOI: 10.1089/ten.TEA.2017.0229 -
European Review For Medical and... Nov 2022To explore the effect of polyethylene glycol loxenatide (long-acting GLP-1R agonist) on the lipid, glucose levels, and weight in type 2 diabetes mellitus patients with... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To explore the effect of polyethylene glycol loxenatide (long-acting GLP-1R agonist) on the lipid, glucose levels, and weight in type 2 diabetes mellitus patients with obesity.
PATIENTS AND METHODS
A total of 40 obese patients with type 2 diabetes mellitus in our hospital from July 2019 to June 2020 were randomly divided into a control group and a study group. The study group was treated with metformin and polyethylene glycol loxenatide injection, while the control group was treated with metformin.
RESULTS
Before treatment, there was no significant difference in FPG (Fasting Blood Glucose) and PPG (Post Prandial Glycaemia) levels between the study group and the control group (p>0.05). After a treatment period, the FPG and PPG levels in the study group were significantly lower than those in the control group (p<0.05). With the longer treatment time, the patient's weight and BMI were lower (p<0.05). The weight and BMI of patients changed the least after one month of treatment, and the weight and BMI changed the most after more than seven months of treatment. After a period of treatment, the levels of FPG and PPG in the blood of male patients in the study group were significantly lower than those of female patients (p<0.05). After treatment, the TG level of the study group was significantly lower than that of the control group (p<0.05). In comparison, the HDL-C level was significantly higher than that of the control group (p<0.05).
CONCLUSIONS
Lipid and glucose levels of type 2 diabetes mellitus patients with obesity have decreased after 12 weeks of polyethylene glycol loxanatide use. The weight of type 2 diabetes mellitus patients with obesity has changed after using polyethylene glycol loxenatide for a period of treatment. Among them, there is a certain relationship between body weight and treatment time, gender, and original body weight, which is worthy of further research and promotion in clinical practice.
Topics: Humans; Male; Female; Diabetes Mellitus, Type 2; Blood Glucose; Obesity; Polyethylene Glycols; Metformin; Lipids
PubMed: 36394750
DOI: 10.26355/eurrev_202211_30153 -
Biomaterials Science Dec 2022Poly(glycerol sebacate) (PGS), a synthetic biorubber, is characterised by its biocompatibility, high elasticity and tunable mechanical properties; however, its inherent...
Poly(glycerol sebacate) (PGS), a synthetic biorubber, is characterised by its biocompatibility, high elasticity and tunable mechanical properties; however, its inherent hydrophobicity and insolubility in water make it unsuitable for use in advanced biomaterials like hydrogels fabrication. Here, we developed new hydrophilic PGS-based copolymers that enable hydrogel formation through use of two different types of polyethylene glycol (PEG), polyethylene glycol (PEG2) or glycerol ethoxylate (PEG3), combined at different ratios. A two-step polycondensation reaction was used to produce poly(glycerol sebacate)--polyethylene glycol (PGS--PEG) copolymers that were then crosslinked thermally without the use of initiators or crosslinkers, resulting in PGS--PEG2 and PGS--PEG3 amphiphilic polymers. It has been illustrated that the properties of PGS--PEG copolymers can be controlled by altering the type and amount of PEG. PGS--PEG copolymers containing PEG ≥ 40% showed high swelling, flexibility, stretching, bioadhesion and biocompatibility, and good enzymatic degradation and mechanical properties. Also, the addition of PEG created hydrogels that demonstrated pH-responsive behaviours, which can be used for bioapplications requiring responding to physicochemical dynamics. Interestingly, PGS--40PEG2 and PGS--60PEG3 had the highest shear strengths, 340.4 ± 49.7 kPa and 336.0 ± 35.1 kPa, and these are within the range of commercially available sealants or bioglues. Due to the versatile multifunctionalities of these new copolymer hydrogels, they can have great potential in soft tissue engineering and biomedicine.
Topics: Glycerol; Polyethylene Glycols; Hydrogen-Ion Concentration
PubMed: 36342181
DOI: 10.1039/d2bm01335e