scholarly journals Swelling Kinetics and Corneal Hydration Level of Kaolinin-HPMC Hydrogel Film

2020 ◽  
Vol 82 (2) ◽  
Author(s):  
ARUNIMA PRAMANIK ◽  
R. N. SAHOO ◽  
A. NANDA ◽  
K. P. PATTNAIK ◽  
S. MALLICK
Keyword(s):  
Swelling Kinetics ◽  
Hydration Level ◽  
Corneal Hydration ◽  
Hydrogel Film

Gelatin/poly(vinyl alcohol) based hydrogel film – A potential biomaterial for wound dressing: Experimental design and optimization followed by rotatable central composite design

2021 ◽  
pp. 088532822199226
Author(s):  
Patricia Hubner ◽  
Nilson Romeu Marcilio ◽  
Isabel Cristina Tessaro
Keyword(s):  
Experimental Design ◽  
Central Composite Design ◽  
Vinyl Alcohol ◽  
Biomedical Applications ◽  
Poly Vinyl Alcohol ◽  
Swelling Kinetics ◽  
Mechanical Resistance ◽  
Hydrogel Film ◽  
Central Composite ◽  
Hydrogel Films

The development of hydrogel films for biomedical applications is interesting due to their characteristics. Hydrogel films based on gelatin and poly(vinyl alcohol) (PVA) are developed and characterized using a rotatable central composite design. The optimized hydrogel film is obtained by the function desirability of the Statistica® software and is also characterized by swelling kinetics, oxygen permeability, adhesiveness, TGA, DSC, and XRD. The results of the experimental design show that gelatin and PVA concentrations have a significant influence on the response variables, and the exposure doses to UV light show no significant effect. The optimized hydrogel film is elastic, presents good mechanical resistance and swelling capacity in water and exudate solution, is permeable to oxygen, and is capable of adjusting itself and maintains contact close to the skin. In this way, considering all the properties evaluated, the optimized film has characteristics suitable for biomedical applications as wound dressings.

scholarly journals Polyelectrolyte Gels: A Unique Class of Soft Materials

Gels ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 102
Author(s):  
Ferenc Horkay
Keyword(s):  
Exchange Process ◽  
Interaction Strength ◽  
Soft Materials ◽  
Industrial Applications ◽  
Future Research ◽  
Swelling Kinetics ◽  
Polyelectrolyte Gels ◽  
Ion Exchange Process ◽  
Counter Ions ◽  
Kinetics Of

The objective of this article is to introduce the readers to the field of polyelectrolyte gels. These materials are common in living systems and have great importance in many biomedical and industrial applications. In the first part of this paper, we briefly review some characteristic properties of polymer gels with an emphasis on the unique features of this type of soft material. Unsolved problems and possible future research directions are highlighted. In the second part, we focus on the typical behavior of polyelectrolyte gels. Many biological materials (e.g., tissues) are charged (mainly anionic) polyelectrolyte gels. Examples are shown to illustrate the effect of counter-ions on the osmotic swelling behavior and the kinetics of the swelling of model polyelectrolyte gels. These systems exhibit a volume transition as the concentration of higher valence counter-ions is gradually increased in the equilibrium bath. A hierarchy is established in the interaction strength between the cations and charged polymer molecules according to the chemical group to which the ions belong. The swelling kinetics of sodium polyacrylate hydrogels is investigated in NaCl solutions and in solutions containing both NaCl and CaCl2. In the presence of higher valence counter-ions, the swelling/shrinking behavior of these gels is governed by the diffusion of free ions in the swollen network, the ion exchange process and the coexistence of swollen and collapsed states.

scholarly journals Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1204
Author(s):  
Mengna Chen ◽  
Xuelong Chen ◽  
Caiyan Zhang ◽  
Baozheng Cui ◽  
Zewen Li ◽  
...  
Keyword(s):  
Water Absorption ◽  
Low Cost ◽  
High Water ◽  
Kinetic Mechanism ◽  
Swelling Kinetics ◽  
Synthesis Conditions ◽  
Ph Tolerance ◽  
Monovalent Salt ◽  
Infrared Spectrometer ◽  
Pseudo Second Order

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

scholarly journals Gold Nanorod Hydrogel Film for Laser‐Induced HIPEC to Treat Peritoneal Malignancies

2021 ◽  
pp. 2100036
Author(s):  
Karem A. Court ◽  
Hangjin Yu ◽  
Diana Chan ◽  
Elvin Blanco ◽  
Arturas Ziemys ◽  
...  
Keyword(s):  
Gold Nanorod ◽  
Hydrogel Film

Effect of iontophoresis on transcorneal permeation ‘in vitro’ of two β-blocking agents, and on corneal hydration

2003 ◽  
Vol 250 (2) ◽  
pp. 423-429 ◽  
Author(s):  
D. Monti ◽  
L. Saccomani ◽  
P. Chetoni ◽  
S. Burgalassi ◽  
M.F. Saettone
Keyword(s):  
Corneal Hydration ◽  
Blocking Agents

scholarly journals Low-fouling CNT-PEG-hydrogel coated quartz crystal microbalance sensor for saliva glucose detection

RSC Advances ◽  
2021 ◽  
Vol 11 (37) ◽  
pp. 22556-22564
Author(s):  
Shiwen Wang ◽  
Guanjiang Liu ◽  
Bei Yang ◽  
Zifeng Zhang ◽  
Debo Hu ◽  
...  
Keyword(s):  
Quartz Crystal Microbalance ◽  
Binding Sites ◽  
Quartz Crystal ◽  
Direct Detection ◽  
Glucose Detection ◽  
Hydrogel Film ◽  
Glucose Binding ◽  
Quartz Crystal Microbalance Sensor

We successfully achieved the direct detection of saliva glucose by a CNT-PEG-hydrogel. The top CNT-PEG layer provides channels for transporting glucose molecules and filters macromolecular impurities and the bottom base PBA-hydrogel film provides the glucose binding sites.

scholarly journals Cavity hydration dynamics in cytochrome c oxidase and functional implications

2017 ◽  
Vol 114 (42) ◽  
pp. E8830-E8836 ◽  
Author(s):  
Chang Yun Son ◽  
Arun Yethiraj ◽  
Qiang Cui
Keyword(s):  
Molecular Dynamics ◽  
Free Energy ◽  
Proton Transfer ◽  
Molecular Dynamics Simulations ◽  
Transmembrane Protein ◽  
Wetting Transition ◽  
Protonation State ◽  
Hydration Level ◽  
Level Change ◽  
Dynamics Simulations

Cytochrome c oxidase (CcO) is a transmembrane protein that uses the free energy of O2 reduction to generate the proton concentration gradient across the membrane. The regulation of competitive proton transfer pathways has been established to be essential to the vectorial transport efficiency of CcO, yet the underlying mechanism at the molecular level remains lacking. Recent studies have highlighted the potential importance of hydration-level change in an internal cavity that connects the proton entrance channel, the site of O2 reduction, and the putative proton exit route. In this work, we use atomistic molecular dynamics simulations to investigate the energetics and timescales associated with the volume fluctuation and hydration-level change in this central cavity. Extensive unrestrained molecular dynamics simulations (accumulatively ∼4 μs) and free energy computations for different chemical states of CcO support a model in which the volume and hydration level of the cavity are regulated by the protonation state of a propionate group of heme a3 and, to a lesser degree, the redox state of heme a and protonation state of Glu286. Markov-state model analysis of ∼2-μs trajectories suggests that hydration-level change occurs on the timescale of 100–200 ns before the proton-loading site is protonated. The computed energetic and kinetic features for the cavity wetting transition suggest that reversible hydration-level change of the cavity can indeed be a key factor that regulates the branching of proton transfer events and therefore contributes to the vectorial efficiency of proton transport.

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