Ion-Pairing Strength in Polyelectrolyte Complexes

2017 ◽  
Vol 50 (3) ◽  
pp. 1066-1074 ◽  
Author(s):  
Jingcheng Fu ◽  
Hadi M. Fares ◽  
Joseph B. Schlenoff
Keyword(s):  
Ion Pairing ◽  
Polyelectrolyte Complexes ◽  
Pairing Strength

Plasma Contact Activation and Decrease of Factor V Activity on Negatively-Charged Polyelectrolytes

1984 ◽  
Vol 51 (01) ◽  
pp. 061-064 ◽  
Author(s):  
M C Boffa ◽  
B Dreyer ◽  
C Pusineri
Keyword(s):  
Time Dependent ◽  
Initial Contact ◽  
Factor Xii ◽  
Factor V ◽  
Contact Activation ◽  
Polyelectrolyte Complexes ◽  
Plasma Factor ◽  
Fresh Plasma ◽  
Direct Adsorption

SummaryThe effect of negatively-charged polymers, used in some artificial devices, on plasma clotting and kinin systems was studied in vitro using polyelectrolyte complexes.Contact activation was observed as an immediate, transient and surface-dependent phenomenon. After incubation of the plasma with the polymer a small decrease of factor XII activity was noticed, which corresponded to a greater reduction of prekallikrein activity and to a marked kinin release. No significant decrease of factor XII, prekallikrein, HMW kininogen could be detected immunologically. Only the initial contact of the plasma with the polyelectrolyte lead to activation, subsequently the surface became inert.Beside contact activation, factor V activity also decreased in the plasma. The decrease was surface and time-dependent. It was independent of contact factor activation, and appeared to be related to the sulfonated groups of the polymer. If purified factor V was used instead of plasma factor V, inactivation was immediate and not time-dependent suggesting a direct adsorption on the surface. A second incubation of the plasma-contacted polymer with fresh plasma resulted in a further loss of Factor V activity.

Ion Pairing and Dielectric Decrement in Glycosaminoglycan Brushes

2020 ◽  
Author(s):  
James Sterling ◽  
Wenjuan Jiang ◽  
Wesley M. Botello-Smith ◽  
Yun L. Luo
Keyword(s):  
Molecular Dynamics ◽  
Ion Pairs ◽  
Mean Field ◽  
Salt Bridge ◽  
Ion Pairing ◽  
Donnan Potential ◽  
Mean Field Models ◽  
Ion Exclusion ◽  
Dynamics Simulations ◽  
Contact Ion Pairs

Molecular dynamics simulations of hyaluronic acid and heparin brushes are presented that show important effects of ion-pairing, water dielectric decrease, and co-ion exclusion. Results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by cations. Most surprising is the reversal of the Donnan potential that would be expected based on electrostatic Boltzmann partitioning alone. Water dielectric decrement within the brush domain is also associated with Born hydration-driven cation exclusion from the brush. We observe that the primary partition energy attracting cations to attain brush electroneutrality is the ion-pairing or salt-bridge energy associated with cation-sulfate and cation-carboxylate solvent-separated and contact ion pairs. Potassium and sodium pairing to glycosaminoglycan carboxylates and sulfates consistently show similar abundance of contact-pairing and solvent-separated pairing. In these crowded macromolecular brushes, ion-pairing, Born-hydration, and electrostatic potential energies all contribute to attain electroneutrality and should therefore contribute in mean-field models to accurately represent brush electrostatics.

Photoisomerization-induced patterning of ion-pairing materials based on anionic azobenzene and its complex with a fluorescent π-electronic system

2021 ◽  
Vol 57 (35) ◽  
pp. 4287-4290
Author(s):  
Ryohei Yamakado ◽  
Issei Kitamura ◽  
Mitsuo Hara ◽  
Shusaku Nagano ◽  
Takahiro Seki ◽  
...  
Keyword(s):  
Surface Tension ◽  
Mass Transport ◽  
Trace Amount ◽  
Ion Pairs ◽  
Ion Pairing ◽  
Electronic System ◽  
Large Mass ◽  
System P ◽  
The Difference

Large mass transport driven by the difference in the photoisomerization-induced surface tension was demonstrated in ion pairs, enabling fluorescence patterning using a trace amount of photoisomerized anions in complexation with a π-electronic system.

Pyrrole-bridged quinones: π-electronic systems that modulate electronic structures by tautomerism and deprotonation

2021 ◽  
Author(s):  
Shinya Sugiura ◽  
Hiromitsu Maeda
Keyword(s):  
Infrared Absorption ◽  
Electronic Structures ◽  
Near Infrared ◽  
Ion Pairing ◽  
Anion Binding ◽  
Electronic Systems

A new series of π-extended quinone derivatives containing a pyrrole bridge exhibited NH/OH-type tautomerization and anion binding along with deprotonation that induced near-infrared absorption and ion-pairing assemblies.

scholarly journals Cyclodextrin-Based Supramolecular Complexes of Osteoinductive Agents for Dental Tissue Regeneration

Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 136
Author(s):  
Masahiko Terauchi ◽  
Atsushi Tamura ◽  
Yoshinori Arisaka ◽  
Hiroki Masuda ◽  
Tetsuya Yoda ◽  
...  
Keyword(s):  
Growth Factors ◽  
Bone Formation ◽  
Small Molecule ◽  
Tissue Regeneration ◽  
Alveolar Bone ◽  
Inclusion Complexation ◽  
Dental Tissue ◽  
Polyelectrolyte Complexes ◽  
Small Molecule Drugs

Oral tissue regeneration has received growing attention for improving the quality of life of patients. Regeneration of oral tissues such as alveolar bone and widely defected bone has been extensively investigated, including regenerative treatment of oral tissues using therapeutic cells and growth factors. Additionally, small-molecule drugs that promote bone formation have been identified and tested as new regenerative treatment. However, treatments need to progress to realize successful regeneration of oral functions. In this review, we describe recent progress in development of regenerative treatment of oral tissues. In particular, we focus on cyclodextrin (CD)-based pharmaceutics and polyelectrolyte complexation of growth factors to enhance their solubility, stability, and bioactivity. CDs can encapsulate hydrophobic small-molecule drugs into their cavities, resulting in inclusion complexes. The inclusion complexation of osteoinductive small-molecule drugs improves solubility of the drugs in aqueous solutions and increases in vitro osteogenic differentiation efficiency. Additionally, various anionic polymers such as heparin and its mimetic polymers have been developed to improve stability and bioactivity of growth factors. These polymers protect growth factors from deactivation and degradation by complex formation through electrostatic interaction, leading to potentiation of bone formation ability. These approaches using an inclusion complex and polyelectrolyte complexes have great potential in the regeneration of oral tissues.

scholarly journals Synthetic, Spectroscopic, Structural, and Electrochemical Investigations of Ferricenium Derivatives with Weakly Coordinating Anions: Ion Pairing, Substituent, and Solvent Effects

2021 ◽  
Author(s):  
Firoz Shah Tuglak Khan ◽  
Amy L Waldbusser ◽  
Maria C. C. Carrasco ◽  
Hadi Pourhadi ◽  
Shabnam Hematian
Keyword(s):  
Solvent Effects ◽  
Ion Pairing ◽  
Effective Strategy ◽  
Weakly Coordinating Anions ◽  
Weakly Coordinating ◽  
Electron Withdrawing Substituents

A facile and effective strategy for the preparation of a series of ferricenium complexes bearing either electron-donating or electron-withdrawing substituents with weakly coordinating anions such as [B(C6F5)4]– or SbF6– is...

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