Crystallization Inhibition of Polyethylene Glycol by Indomethacin: Formation and Disruption of Hydrogen Bonds

A Robust, Tough and Multifunctional Polyurethane/Tannic Acid Hydrogel Fabricated by Physical-Chemical Dual Crosslinking

Polymers ◽

10.3390/polym12010239 ◽

2020 ◽

Vol 12 (1) ◽

pp. 239 ◽

Cited By ~ 1

Author(s):

Jie Wen ◽

Xiaopeng Zhang ◽

Mingwang Pan ◽

Jinfeng Yuan ◽

Zhanyu Jia ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Polyethylene Glycol ◽

Hydrogen Bonds ◽

Tannic Acid ◽

Hydroxyl Groups ◽

Self Healing ◽

Physical Chemical ◽

Biomedical Field ◽

Physical Crosslinking

Commonly synthetic polyethylene glycol polyurethane (PEG–PU) hydrogels possess poor mechanical properties, such as robustness and toughness, which limits their load-bearing application. Hence, it remains a challenge to prepare PEG–PU hydrogels with excellent mechanical properties. Herein, a novel double-crosslinked (DC) PEG–PU hydrogel was fabricated by combining chemical with physical crosslinking, where trimethylolpropane (TMP) was used as the first chemical crosslinker and polyphenol compound tannic acid (TA) was introduced into the single crosslinked PU network by simple immersion process. The second physical crosslinking was formed by numerous hydrogen bonds between urethane groups of PU and phenol hydroxyl groups in TA, which can endow PEG–PU hydrogel with good mechanical properties, self-recovery and a self-healing capability. The research results indicated that as little as a 30 mg·mL−1 TA solution enhanced the tensile strength and fracture energy of PEG–PU hydrogel from 0.27 to 2.2 MPa, 2.0 to 9.6 KJ·m−2, respectively. Moreover, the DC PEG–PU hydrogel possessed good adhesiveness to diverse substrates because of TA abundant catechol groups. This work shows a simple and versatile method to prepare a multifunctional DC single network PEG–PU hydrogel with excellent mechanical properties, and is expected to facilitate developments in the biomedical field.

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Intramolecular Hydrogen Bonds in Low-Molecular-Weight Polyethylene Glycol

ChemPhysChem ◽

10.1002/cphc.201501182 ◽

2016 ◽

Vol 17 (8) ◽

pp. 1143-1153 ◽

Cited By ~ 14

Author(s):

Mariana Kozlowska ◽

Jakub Goclon ◽

Pawel Rodziewicz

Keyword(s):

Molecular Weight ◽

Polyethylene Glycol ◽

Hydrogen Bonds ◽

Low Molecular Weight ◽

Intramolecular Hydrogen Bonds ◽

Intramolecular Hydrogen

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Fully Supramolecular Polyrotaxanes as Biphase Drug Delivery Systems

International Journal of Polymer Science ◽

10.1155/2014/829474 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Abdolhossien Massoudi ◽

Mohsen Adeli ◽

Leila Khosravi far

Keyword(s):

Drug Delivery ◽

Polyethylene Glycol ◽

Citric Acid ◽

Hydrogen Bonds ◽

Drug Delivery Systems ◽

Noncovalent Interactions ◽

Delivery Systems ◽

End Groups ◽

Model Drug ◽

Primary Drug

Pseudopolyrotaxanes (PPR) consisting ofα-cyclodextrin rings and polyethylene glycol axes with end thymine groups have been synthesized and characterized successfully. Fluorescein (Fl) as a model drug was conjugated to the hydroxyl functional groups of cyclodextrin rings of PPR via ester bonds and PPR-Fl as the primary drug delivery system was obtained. Finally PPR-Fl was capped by hydrogen bonds between end thymine groups and a suitable complementary molecule such as polycitric acid, citric acid, or adenine. The aim of this work was to control the release of the fluorescein-cyclodextrin (Fl-CD) conjugates, as the secondary drug delivery systems, from PPR-Fl by controlling the noncovalent interactions between stoppers and thymine end groups. It was found that the rate of release of the Fl-CD from PPR-Fl could be controlled by pH and the ratio of citric acid or adenine to the PPR-Fl.

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Immunocytochemical detection of hepatic carbohydrate metabolic enzymes: Improved resolution with polyethylene glycol embedding and visio-bond semithin sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100124367 ◽

1992 ◽

Vol 50 (1) ◽

pp. 792-793

Author(s):

Kuixiong Gao ◽

Randal E. Morris ◽

Bruce F. Giffin ◽

Robert R. Cardell

Keyword(s):

Polyethylene Glycol ◽

Glycogen Phosphorylase ◽

Phosphoenolpyruvate Carboxykinase ◽

Glycogen Synthase ◽

Metabolic Enzymes ◽

Silver Stain ◽

Accurate Localization ◽

Immunocytochemical Detection ◽

Semithin Sections ◽

Parenchymal Cells

Several enzymes are involved in the regulation of anabolic and catabolic pathways of carbohydrate metabolism in liver parenchymal cells. The lobular distribution of glycogen synthase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen phosphorylase (GP) was studied by immunocytochemistry using cryosections of normal fed and fasted rat liver. Since sections of tissue embedded in polyethylene glycol (PEG) show good morphological preservation and increased detectability for immunocytochemical localization of antigenic sites, and semithin sections of Visio-Bond (VB) embedded tissue provide higher resolution of cellular structure, we applied these techniques and immunogold-silver stain (IGSS) for a more accurate localization of hepatic carbohydrate metabolic enzymes.

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Directional observation on lipid of male nectary of Lindera megaphylla hemsl. by the rapid embedding method with polyethylene glycol (PEG)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161151 ◽

1990 ◽

Vol 48 (3) ◽

pp. 718-719

Author(s):

Dai Dalin ◽

Guo Jianmin

Keyword(s):

Electron Microscope ◽

Polyethylene Glycol ◽

Chemical Reaction ◽

Traditional Method ◽

Osmium Tetroxide ◽

Unsaturated Lipid ◽

Embedding Method ◽

Long Period ◽

New Methods

Lipid cytochemistry has not yet advanced far at the EM level. A major problem has been the loss of lipid during dehydration and embedding. Although the adoption of glutaraldehyde and osmium tetroxide accelerate the chemical reaction of lipid and osmium tetroxide can react on the double bouds of unsaturated lipid to from the osmium black, osmium tetroxide can be reduced in saturated lipid and subsequently some of unsaturated lipid are lost during dehydration. In order to reduce the loss of lipid by traditional method, some researchers adopted a few new methods, such as the change of embedding procedure and the adoption of new embedding media, to solve the problem. In a sense, these new methods are effective. They, however, usually require a long period of preparation. In this paper, we do research on the fiora nectary strucure of lauraceae by the rapid-embedding method wwith PEG under electron microscope and attempt to find a better method to solve the problem mentioned above.

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