scholarly journals Effect of Experimental Parameters on the Formation of Hydrogels by Polyelectrolyte Complexation of Carboxymethylcellulose, Carboxymethyl Starch, and Alginic Acid with Chitosan

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Elizabeth Henao Mejía ◽  
Héctor Contreras ◽  
Ezequiel Delgado ◽  
Germán Quintana
Keyword(s):  
Zeta Potential ◽  
Electric Charge ◽  
Alginic Acid ◽  
Gelation Time ◽  
Three Dimensional ◽  
Anionic Polymer ◽  
Carboxymethyl Starch ◽  
Polyelectrolyte Complexation ◽  
Experimental Parameters ◽  
Negative Zeta Potential

Differences in morphology, pH, and electric charge of chitosan (CS) based hydrogels prepared by complexation with carboxymethylcellulose (CMC), carboxymethylated starch (CMS), and alginic acid (AA) at different polymers ratios and changing the order of addition were studied. CMC/CS and AA/CS hydrogels were amorphous and porous three-dimensional networks, with smaller pores at higher anionic polymer/CS ratios. Gelation time increased the agglomeration in the case of CMC/CS and CMS/CS gels. CMC/CS gels showed negative zeta potential values around −372 mV to −51 mV and CMS/CS gels in the range of −526 mV and −158 mV.

scholarly journals Gum Tragacanth (GT): A Versatile Biocompatible Material beyond Borders

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1510 ◽  
Author(s):  
Mohammad Ehsan Taghavizadeh Yazdi ◽  
Simin Nazarnezhad ◽  
Seyed Hadi Mousavi ◽  
Mohammad Sadegh Amiri ◽  
Majid Darroudi ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Food Packaging ◽  
Three Dimensional ◽  
Great Promise ◽  
Anionic Polymer ◽  
Gum Tragacanth ◽  
New Horizons ◽  
Tissue Healing ◽  
The Stability ◽  
Therapeutic Substance

The use of naturally occurring materials in biomedicine has been increasingly attracting the researchers’ interest and, in this regard, gum tragacanth (GT) is recently showing great promise as a therapeutic substance in tissue engineering and regenerative medicine. As a polysaccharide, GT can be easily extracted from the stems and branches of various species of Astragalus. This anionic polymer is known to be a biodegradable, non-allergenic, non-toxic, and non-carcinogenic material. The stability against microbial, heat and acid degradation has made GT an attractive material not only in industrial settings (e.g., food packaging) but also in biomedical approaches (e.g., drug delivery). Over time, GT has been shown to be a useful reagent in the formation and stabilization of metal nanoparticles in the context of green chemistry. With the advent of tissue engineering, GT has also been utilized for the fabrication of three-dimensional (3D) scaffolds applied for both hard and soft tissue healing strategies. However, more research is needed for defining GT applicability in the future of biomedical engineering. On this object, the present review aims to provide a state-of-the-art overview of GT in biomedicine and tries to open new horizons in the field based on its inherent characteristics.

scholarly journals Production and Characterization of Chitosan–Polyanion Nanoparticles by Polyelectrolyte Complexation Assisted by High-Intensity Sonication for the Modified Release of Methotrexate

2020 ◽  
Vol 13 (1) ◽  
pp. 11 ◽  
Author(s):  
Yhors Ciro ◽  
John Rojas ◽  
Maria Alhajj ◽  
Gustavo Carabali ◽  
Constain Salamanca
Keyword(s):  
Zeta Potential ◽  
Maleic Acid ◽  
High Intensity ◽  
Physical Stability ◽  
Release Mechanism ◽  
Diffusion Controlled ◽  
Polyelectrolyte Complexation ◽  
Anticancer Treatment ◽  
Particle Parameters

A promising strategy to improve the effectivity of anticancer treatment and decrease its side effects is to modulate drug release by using nanoparticulates (NPs) as carriers. In this study, methotrexate-loaded chitosan–polyanion nanoparticles were produced by polyelectrolyte complexation assisted by high-intensity sonication, using several anionic polymers, such as the sodium and potassium salts of poly(maleic acid-alt-ethylene) and poly(maleic acid-alt-octadecene), here named PAM-2 and PAM-18, respectively. Such NPs were analyzed and characterized according to particle size, polydispersity index, zeta potential and encapsulation efficiency. Likewise, their physical stability was tested at 4 °C and 40 °C in order to evaluate any change in the previously mentioned particle parameters. The in vitro methotrexate release was assessed at a pH of 7.4, which simulated physiological conditions, and the data were fitted to the heuristic models of order one, Higuchi, Peppas–Sahlin and Korsmeyer–Peppas. The results revealed that most of the MTX-chitosan–polyanion NPs have positive zeta potential values, sizes <280 nm and monodisperse populations, except for the NPs formed with PAM-18 polyanions. Further, the NPs showed adequate physical stability, preventing NP–NP aggregation. Likewise, these carriers modified the MTX release by an anomalous mechanism, where the NPs formed with PAM-2 polymer led to a release mechanism controlled by diffusion and relaxation, whereas the NPs formed with PAM-18 led to a mainly diffusion-controlled release mechanism.

Influence of Surface Zeta Potential on Adhesion of Chlorella sp. to Substratum Surfaces

2013 ◽  
Vol 690-693 ◽  
pp. 1431-1434
Author(s):  
Xin Ru Zhang ◽  
Ze Yi Jiang ◽  
Hao Yuan ◽  
Yuan Xiang Lu ◽  
Liang Chen ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Cell Surface ◽  
Mass Culture ◽  
Chlorella Sp ◽  
Microalgae Mass Culture ◽  
Negative Zeta Potential

Microalgae, in wet conditions, tend to grow on surfaces and form biofilms. The adhesion of microalgae to surfaces is very important for algal mass culture. The formation and development of microalgal biofims are in large denpend on the properties of cell surface, substratum surface and gowth medium. In this paper, the influence of substratum surface zeta potential on the microalgal biofilms was particularly investigated. We focused on a widely-used microalgal strain, the freshwater autotrophicChlorella sp..The adhesion phenomena ofChlorella sp.to surfaces with different zeta potential were observed microscopically. It was found thatChlorella sp.adhered easily to the surface with a positive zeta potential and difficultly to the surface with a negative zeta potential. We concluded that the surface zeta potential had a greater influence on the adhesion of microalgal cells to substratum surfaces. Our findings have important implications for microalgae mass culture and harvesting.

scholarly journals Analysis of Te Inclusion Striations in (Cd,Zn)Te Crystals Grown by Traveling Heater Method

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 649
Author(s):  
Jiaona Zou ◽  
Alex Fauler ◽  
Alexander S. Senchenkov ◽  
Nikolai N. Kolesnikov ◽  
Michael Fiederle
Keyword(s):  
Growth Parameters ◽  
Three Dimensional ◽  
Three Dimensional Mapping ◽  
Zn Content ◽  
Experimental Parameters ◽  
Te Inclusions ◽  
Rich Solution ◽  
Traveling Heater Method ◽  
Periodic Temperature ◽  
Dimensional Mapping

The growth of (Cd,Zn)Te (CZT) crystals and the improvement of the crystal quality are part of a research project towards experiments under microgravity using the Traveling Heater Method (THM). In order to determine the experimental parameters, we performed a detailed ground-based program. Three CZT crystals with a nominal Zn content of 10% were grown using THM from a Te-rich solution. The size and distribution of the Te inclusions were evaluated by transmission infrared microscopy (IR). From the three-dimensional mapping of the inclusions, we observed striation-like patterns in all of the crystals. The correlation between the growth parameters and the formation of these striations was explored and discussed. We found that the inclusion striations are related to periodic temperature variations.

Enhanced growth and matrix production by human osteoblastic cells cultured on biomaterials with negative zeta potential

Bone ◽  
2009 ◽  
Vol 44 ◽  
pp. S259 ◽  
Author(s):  
J.P. Dillon ◽  
P.J.M. Wilson ◽  
W.D. Fraser ◽  
B.K. Mwaura ◽  
M.J. Hayton ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Osteoblastic Cells ◽  
Matrix Production ◽  
Human Osteoblastic Cells ◽  
Negative Zeta Potential ◽  
Cells Cultured

Effect of Different Anions on 22Na Permeability of Liposomes

1973 ◽  
Vol 51 (11) ◽  
pp. 779-784 ◽  
Author(s):  
M. A. Singer
Keyword(s):  
Zeta Potential ◽  
Dipole Potential ◽  
Sodium Permeability ◽  
Phosphatidylcholine Liposomes ◽  
Solution Interface ◽  
Cation Permeability ◽  
Na Efflux ◽  
Negative Zeta Potential

The 22Na efflux from phosphatidylcholine liposomes was measured in the presence of different anions. Only salicylate significantly increases sodium permeability. Although this anion adsorbs onto the liposomal surface creating a negative zeta potential, evidence is presented that this is not the sole mechanism underlying the enhanced cation permeability. It is proposed that salicylate also alters the dipole potential at the membrane–solution interface.

Bioleaching Solutions Used for the Nanoparticles Biosynthesis for Uranium and Arsenic Immobilization

2020 ◽  
Vol 304 ◽  
pp. 45-50
Author(s):  
Agnieszka Pawlowska ◽  
Zygmunt Sadowski
Keyword(s):  
Zeta Potential ◽  
Solid Waste ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Plant Extract ◽  
Uranium Dioxide ◽  
Electrical Potential ◽  
Nanoparticle Synthesis ◽  
Negative Zeta Potential

Bioleaching solutions from uranium and arsenic solid waste served as a source of U(VI) and As (V) ions, while plant extract from green tea (Camellia sinensis) – as a reductor for nanoparticle synthesis. Uranium dioxide and As (III) nanoparticles were formed as a product of bioreduction on the hematite and schwertmannite surfaces respectively, which resulted in an increase in the negative zeta potential with an increase in pH. It suggests, that the electrical potential depends on the presence of nanoparticles. The SEM microphotographs revealed the UO2 nanoparticles on the hematite surface.

Tumor Targeting of Plasmid DNA by Dextran Conjugation Based on Metal Coordination

2005 ◽  
Vol 288-289 ◽  
pp. 109-112
Author(s):  
H. Hosseinkhani ◽  
T. Aoyama ◽  
O. Ogawa ◽  
Yasuhiko Tabata
Keyword(s):  
Gene Expression ◽  
Zeta Potential ◽  
Plasmid Dna ◽  
Tumor Targeting ◽  
Metal Coordination ◽  
Hydroxyl Groups ◽  
Negative Zeta Potential

Tumor targeting of plasmid DNA was achieved through the conjugation of dextran derivative with chelate residue based on metal coordination. Spermine (Sm) was chemically introduced to the hydroxyl groups of dextran to obtain dextran-Sm derivative. A negative zeta potential of plasmid DNA became almost 0 mV by the Zn2+-coordinated conjugation with the dextran-Sm When the dextran-Sm-plasmid DNA conjugate with Zn2+ coordination was intravenously injected to mice subcutaneously bearing Meth-AR-1 fibrosarcoma, the dextran- Sm-plasmid DNA conjugate significantly enhanced the level of gene expression in the tumor, in contrast to free plasmid DNA..

Direct Ink Printing of Cavities in DPC Ceramic Substrates With Kaolin Pastes for Hermetic Packaging

2019 ◽  
Author(s):  
Qinglei Sun ◽  
Yang Peng ◽  
Hao Cheng ◽  
Yun Mou ◽  
Mingxiang Chen
Keyword(s):  
Zeta Potential ◽  
Viscoelastic Properties ◽  
Three Dimensional ◽  
Kaolin Clay ◽  
Ceramic Substrates ◽  
Light Emitting ◽  
Zeta Potentials ◽  
Hermetic Packaging ◽  
Content Variation ◽  
Ultraviolet Light Emitting Diodes

Abstract Fabrication of three-dimensional cavities containing kaolin pastes to be used as direct plated copper (3DPC) substrates ceramics is a very important advancement for electronic packaging of hermetic and ultraviolet light emitting diodes. This work demonstrates usage of pastes consisting of 32–40 wt% of kaolin clay and polyacrylic acid for direct ink printing (DIP) of 3DPC. Rheological and zeta potential tests were performed to determine printability and stability, respectively, of these kaolin pastes. Kaolin content variation had minimum effect on absolute values of the zeta potentials. All pastes had enough stability with the absolute values larger than 30 mV. 40 wt% kaolin solids mass paste was the optimal for DIP due to its excellent shear thinning and viscoelastic properties. Cured 40 wt% kaolin solids mass paste had superior compressive, flexural and bonding strengths. DIP using pastes containing 40 wt% of kaolin is promising for electronic chip integrated hermetic packaging.

scholarly journals In Vitro and Ex Vivo Evaluation of Nepafenac-Based Cyclodextrin Microparticles for Treatment of Eye Inflammation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 709 ◽  
Author(s):  
Blanca Lorenzo-Veiga ◽  
Patricia Diaz-Rodriguez ◽  
Carmen Alvarez-Lorenzo ◽  
Thorsteinn Loftsson ◽  
Hakon Hrafn Sigurdsson
Keyword(s):  
Zeta Potential ◽  
Physicochemical Properties ◽  
Inflammatory Mediators ◽  
Ex Vivo ◽  
Posterior Segment ◽  
Inflammatory Activity ◽  
Commercial Formulation ◽  
Anti Inflammatory ◽  
Negative Zeta Potential

The aim of this study was to design and evaluate novel cyclodextrin (CD)-based aggregate formulations to efficiently deliver nepafenac topically to the eye structure, to treat inflammation and increase nepafenac levels in the posterior segment, thus attenuating the response of inflammatory mediators. The physicochemical properties of nine aggregate formulations containing nepafenac/γ-CD/hydroxypropyl-β (HPβ)-CD complexes as well as their rheological properties, mucoadhesion, ocular irritancy, corneal and scleral permeability, and anti-inflammatory activity were investigated in detail. The results were compared with a commercially available nepafenac suspension, Nevanac® 3 mg/mL. All formulations showed microparticles, neutral pH, and negative zeta potential (–6 to –27 mV). They were non-irritating and nontoxic and showed high permeation through bovine sclera. Formulations containing carboxymethyl cellulose (CMC) showed greater anti-inflammatory activity, even higher than the commercial formulation, Nevanac® 0.3%. The optimized formulations represent an opportunity for topical instillation of drugs to the posterior segment of the eye.

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