Linear rheological properties of low molecular weight polyethylene glycol solutions

Azri, Aziz; Privat, Mireille; Grohens, Yves; Aubry, Thierry

doi:10.1016/j.jcis.2012.10.059

Cited by 11 publications

(9 citation statements)

References 20 publications

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“…To this end, we use a powerful combination of experimental probes, i.e., dynamic light scattering, cryo-TEM, and shear rheometry. We report on the reversible physical gelation of hydrogel fibers of molecule 1 due to strong interactions transmitted through the hydrophobicity of the helical PEG chains 57 and assisted by the HPB packing. Topologically entangled fiber solutions are needed for the gel to form, and the hydrogels show an exceptionally strong dependence of the shear modulus on concentration.…”

Section: Introductionmentioning

confidence: 99%

Strong Physical Hydrogels from Fibrillar Supramolecular Assemblies of Poly(ethylene glycol) Functionalized Hexaphenylbenzenes

et al. 2016

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Gel formation without chemical cross-links requires strong physical bonds, as observed in diverse molecular and macromolecular systems or supramolecular assemblies above a critical concentration. Here, we present a new molecular amphiphile of propeller-like hexaphenylbenzene derivative bearing two short poly(ethylene glycol) (PEG) chains which forms reversible physical gels comprising long (∼2.2 μm) bundles of hydrogel fibrils in coexistence with spherical micelles. Combination of topological (entanglement-like) interactions between the fibers and specific hydrophobic interactions due to the helicity of the PEG chains is proposed to account for the hydrogelation in the semidilute regime. The present supramolecular hydrogels, which are based on small molecules, exhibit extraordinary properties with an exceptionally strong dependence of the shear modulus on concentration, akin to the behavior of ultrahigh molecular weight cellulose-based fibers.

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Section: Introductionmentioning

confidence: 99%

Strong Physical Hydrogels from Fibrillar Supramolecular Assemblies of Poly(ethylene glycol) Functionalized Hexaphenylbenzenes

et al. 2016

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“…It was evident, however, that following the initial drop in temperature, viscosity generally remained constant. Azri et al characterized the linear viscoelastic behavior of low molecular weight PEG by studying the rheological response of 0.6 kDa PEG over a frequency range of 0.16–16 Hz (46). The experiments were conducted at different temperatures and it was found that all samples exhibited Newtonian behavior over the entire range of frequencies.…”

Section: Introductionmentioning

confidence: 99%

A Preliminary Computational Investigation Into the Flow of PEG in Rat Myocardial Tissue for Regenerative Therapy

Ngoepe

Passos

Balabani

et al. 2019

Front. Cardiovasc. Med.

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Myocardial infarction (MI), a type of cardiovascular disease, affects a significant proportion of people around the world. Traditionally, non-communicable chronic diseases were largely associated with aging populations in higher income countries. It is now evident that low- to middle-income countries are also affected and in these settings, younger individuals are at high risk. Currently, interventions for MI prolong the time to heart failure. Regenerative medicine and stem cell therapy have the potential to mitigate the effects of MI and to significantly improve the quality of life for patients. The main drawback with these therapies is that many of the injected cells are lost due to the vigorous motion of the heart. Great effort has been directed toward the development of scaffolds which can be injected alongside stem cells, in an attempt to improve retention and cell engraftment. In some cases, the scaffold alone has been seen to improve heart function. This study focuses on a synthetic polyethylene glycol (PEG) based hydrogel which is injected into the heart to improve left ventricular function following MI. Many studies in literature characterize PEG as a Newtonian fluid within a specified shear rate range, on the macroscale. The aim of the study is to characterize the flow of a 20 kDa PEG on the microscale, where the behavior is likely to deviate from macroscale flow patterns. Micro particle image velocimetry (μPIV) is used to observe flow behavior in microchannels, representing the gaps in myocardial tissue. The fluid exhibits non-Newtonian, shear-thinning behavior at this scale. Idealized two-dimensional computational fluid dynamics (CFD) models of PEG flow in microchannels are then developed and validated using the μPIV study. The validated computational model is applied to a realistic, microscopy-derived myocardial tissue model. From the realistic tissue reconstruction, it is evident that the myocardial flow region plays an important role in the distribution of PEG, and therefore, in the retention of material.

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“…Most in vitro crowding studies use synthetic polymers, similar in size to the majority of small proteins in cells, at concentrations similar to those found in cells (20 -40% w/v). Polysaccharides, such as dextran, polyethylene glycol (PEG) and Ficoll, are advantageous as crowders because they are inert, nonbinding, commercially available in a range of molecular weights, and can often be described by basic polymer theory [17][18][19][20][21][22][23]. While these crowders are often used interchangeably to mimic cellular crowding, they differ considerably in their structure and conformational shape.…”

Section: Introductionmentioning

confidence: 99%

Crowding Induces Entropically-Driven Changes to DNA Dynamics That Depend on Crowder Structure and Ionic Conditions

et al. 2018

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Macromolecular crowding plays a principal role in a wide range of biological processes including gene expression, chromosomal compaction, and viral infection. However, the impact that crowding has on the dynamics of nucleic acids remains a topic of debate. To address this problem, we use single-molecule fluorescence microscopy and custom particle-tracking algorithms to investigate the impact of varying macromolecular crowding conditions on the transport and conformational dynamics of large DNA molecules. Specifically, we measure the mean-squared center-of-mass displacements, as well as the conformational size, shape, and fluctuations, of individual 115 kbp DNA molecules diffusing through various in vitro solutions of crowding polymers. We determine the role of crowder structure and concentration, as well as ionic conditions, on the diffusion and configurational dynamics of DNA. We find that branched, compact crowders (10 kDa PEG, 420 kDa Ficoll) drive DNA to compact, whereas linear, flexible crowders (10, 500 kDa dextran) cause DNA to elongate. Interestingly, the extent to which DNA mobility is reduced by increasing crowder concentrations appears largely insensitive to crowder structure (branched vs. linear), despite the highly different configurations DNA assumes in each case. We also characterize the role of ionic conditions on crowding-induced DNA dynamics. We show that both DNA diffusion and conformational size exhibit an emergent non-monotonic dependence on salt concentration that is not seen in the absence of crowders.

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Linear rheological properties of low molecular weight polyethylene glycol solutions

Cited by 11 publications

References 20 publications

Strong Physical Hydrogels from Fibrillar Supramolecular Assemblies of Poly(ethylene glycol) Functionalized Hexaphenylbenzenes

Strong Physical Hydrogels from Fibrillar Supramolecular Assemblies of Poly(ethylene glycol) Functionalized Hexaphenylbenzenes

A Preliminary Computational Investigation Into the Flow of PEG in Rat Myocardial Tissue for Regenerative Therapy

Crowding Induces Entropically-Driven Changes to DNA Dynamics That Depend on Crowder Structure and Ionic Conditions

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