Influence of divalent ions on composition and viscoelasticity of polyelectrolyte complexes

2021 ◽  
Author(s):  
Divya Iyer ◽  
Vaqar M. S. Syed ◽  
Samanvaya Srivastava
Keyword(s):  
Divalent Ions ◽  
Polyelectrolyte Complexes

Dopant aggregation and precipitation in alkali halides doped with divalent ions

1980 ◽  
Vol 41 (C6) ◽  
pp. C6-68-C6-71 ◽  
Author(s):  
J. Corish ◽  
J. M. Quigley ◽  
C. R. A. Catlow ◽  
P. W.M. Jacobs
Keyword(s):  
Alkali Halides ◽  
Divalent Ions

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.

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 Deciphering the Role of π-Interactions in Polyelectrolyte Complexes Using Rationally Designed Peptides

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2074
Author(s):  
Sara Tabandeh ◽  
Cristina Elisabeth Lemus ◽  
Lorraine Leon
Keyword(s):  
Hydrogen Bonding ◽  
Phase Separation ◽  
Liquid Phase ◽  
Charge Density ◽  
Secondary Structures ◽  
Liquid Phase Separation ◽  
Polyelectrolyte Complexes ◽  
Π Interactions ◽  
Liquid Liquid Phase Separation

Electrostatic interactions, and specifically π-interactions play a significant role in the liquid-liquid phase separation of proteins and formation of membraneless organelles/or biological condensates. Sequence patterning of peptides allows creating protein-like structures and controlling the chemistry and interactions of the mimetic molecules. A library of oppositely charged polypeptides was designed and synthesized to investigate the role of π-interactions on phase separation and secondary structures of polyelectrolyte complexes. Phenylalanine was chosen as the π-containing residue and was used together with lysine or glutamic acid in the design of positively or negatively charged sequences. The effect of charge density and also the substitution of fluorine on the phenylalanine ring, known to disrupt π-interactions, were investigated. Characterization analysis using MALDI-TOF mass spectroscopy, H NMR, and circular dichroism (CD) confirmed the molecular structure and chiral pattern of peptide sequences. Despite an alternating sequence of chirality previously shown to promote liquid-liquid phase separation, complexes appeared as solid precipitates, suggesting strong interactions between the sequence pairs. The secondary structures of sequence pairs showed the formation of hydrogen-bonded structures with a β-sheet signal in FTIR spectroscopy. The presence of fluorine decreased hydrogen bonding due to its inhibitory effect on π-interactions. π-interactions resulted in enhanced stability of complexes against salt, and higher critical salt concentrations for complexes with more π-containing amino acids. Furthermore, UV-vis spectroscopy showed that sequences containing π-interactions and increased charge density encapsulated a small charged molecule with π-bonds with high efficiency. These findings highlight the interplay between ionic, hydrophobic, hydrogen bonding, and π-interactions in polyelectrolyte complex formation and enhance our understanding of phase separation phenomena in protein-like structures.

scholarly journals Evolution of biobased and nanotechnology packaging – a review

2020 ◽  
Vol 35 (4) ◽  
pp. 491-515
Author(s):  
Tom Lindström ◽  
Folke Österberg
Keyword(s):  
Biodegradable Polymers ◽  
Food Packaging ◽  
Environmental Issues ◽  
Barrier Properties ◽  
Environmental Problems ◽  
Layer By Layer ◽  
Polyelectrolyte Complexes ◽  
Life Issues ◽  
Technological Developments ◽  
End Of Life Issues

AbstractThis review deals with the evolution of bio-based packaging and the emergence of various nanotechnologies for primary food packaging. The end-of life issues of packaging is discussed and particularly the environmental problems associated with microplastics in the marine environment, which serve as a vector for the assimilation of persistent organic pollutants in the oceans and are transported into the food chain via marine and wild life. The use of biodegradable polymers has been a primary route to alleviate these environmental problems, but for various reasons the market has not developed at a sufficient pace that would cope with the mentioned environmental issues. Currently, the biodegradable plastics only constitute a small fraction of the fossil-based plastic market. Fossil-based plastics are, however, indispensable for food safety and minimization of food waste, and are not only cheap, but has generally more suitable mechanical and barrier properties compared to biodegradable polymers. More recently, various nanotechnologies such as the use of nanoclays, nanocellulose, layer-by-layer technologies and polyelectrolyte complexes have emerged as viable technologies to make oxygen and water vapor barriers suitable for food packaging. These technological developments are highlighted as well as issues like biodegradation, recycling, legislation issues and safety and toxicity of these nanotechnologies.

Chitosan/heparin blends in ionic liquid produce polyelectrolyte complexes that quickly adsorb citrate-capped silver nanoparticles, forming bactericidal composites

2021 ◽  
Vol 330 ◽  
pp. 115548
Author(s):  
Paulo R. Souza ◽  
Bruno H. Vilsinski ◽  
Ariel C. de Oliveira ◽  
Sharise B.R. Berton ◽  
Cátia S. Nunes ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Ionic Liquid ◽  
Polyelectrolyte Complexes
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