scholarly journals Protein-mediated gelation and nano-scale assembly of unfunctionalized hyaluronic acid and chondroitin sulfate

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1827
Author(s):  
Anthony Tabet ◽  
June Y. Park ◽  
Jarrod Shilts ◽  
Kamil Sokolowski ◽  
Vijay K. Rana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Nervous System ◽  
Hyaluronic Acid ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Chondroitin Sulfate ◽  
Biological Tissues ◽  
Simple Method ◽  
Vis Spectroscopy

Background: Hyaluronic acid (HA) is a major component of the extracellular matrix (ECM) in the central nervous system and the only purely supramolecular glycosaminoglycan. Much focus has been given to using this high molecular weight polysaccharide for tissue engineering applications. In most studies, the backbone of HA is functionalized with moieties that can facilitate network formation through physical self-assembly, or covalent crosslinking (e.g. photo-catalyzed) at concentrations where the polysaccharide does not gel on its own. However, these crosslinks often utilize functional groups not found in biological tissues. Methods: Oscillatory rheology, dynamic light scattering, and scanning electron microscopy were used to study albumin/HA structures. Dynamic light scattering and transmission electron microscopy were used to study albumin/chondroitin sulfate (CS) structures. UV-vis spectroscopy was used to demonstrate the potential for using protein-polymer blends as an ECM-mimetic model to study transport of small molecules. Results: We examine the intermolecular interactions of two major glycosaminoglycans found in the human brain, HA and the lower molecular weight CS, with the model protein albumin. We report the properties of the resulting micro- and nano materials. Our albumin/HA systems formed gels, and albumin/CS systems formed micro- and nanoparticles. These systems are formed from unfunctionalized polysaccharides, which is an attractive and simple method of forming HA hydrogels and CS nanoparticles. We also summarize the concentrations of HA and CS found in various mammalian brains, which could potentially be useful for biomimetic scaffold development. Conclusions: Simple preparation of commercially available charged biomacromolecules results in interesting materials with structures at the micron and nanometer length-scales. Such materials may have utility in serving as cost-effective models of nervous system electrostatic interactions and as in vitro drug release and model system for ECM transport studies.

scholarly journals Protein-mediated gelation and nano-scale assembly of unfunctionalized hyaluronic acid and chondroitin sulfate

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1827
Author(s):  
Anthony Tabet ◽  
June Y. Park ◽  
Jarrod Shilts ◽  
Kamil Sokolowski ◽  
Vijay K. Rana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Molecular Weight ◽  
Nervous System ◽  
Hyaluronic Acid ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Chondroitin Sulfate ◽  
Self Assembly ◽  
Biological Tissues

Background: Hyaluronic acid (HA) is a major component of the extracellular matrix (ECM) in the central nervous system and the only purely supramolecular glycosaminoglycan. Much focus has been given to using this high molecular weight polysaccharide for tissue engineering applications. In most studies, HA is covalently functionalized with moieties that can facilitate network formation through physical self-assembly, or covalent crosslinking (e.g. photo-catalyzed) as the polysaccharide does not gel on its own. However, these crosslinks are not the driving force of HA self-assembly in biological tissues. Methods: Oscillatory rheology, dynamic light scattering, and scanning electron microscopy were used to study albumin/HA structures. Dynamic light scattering and transmission electron microscopy were used to study albumin/chondroitin sulfate (CS) structures. UV-vis spectroscopy was used to demonstrate the potential for using protein-crosslinked polymers as an ECM-mimetic model to study transport of hydrophilic small molecules. Results: We examine the intermolecular interactions of two major glycosaminoglycans found in the human brain, HA and the lower molecular weight CS, with the model protein albumin. We report the properties of the resulting micro- and nano-materials. Albumin/HA mixtures formed supramolecular gels, and albumin/CS mixtures formed micro- and nanoparticles. These systems are formed from unfunctionalized polysaccharides, which is an attractive and simpler method of forming HA hydrogels and CS nanoparticles than functional chemistry-based approaches such as chemically modifying the polymer backbones. We also summarize the concentrations of HA and CS found in various mammalian brains, which could potentially be useful for biomimetic scaffold development in tissue engineering. Conclusions: Simple preparation and combination of commercially available charged biomacromolecules rapidly result in interesting self-assembled materials with structures at the micron and nanometer length-scales. Such materials may have utility in serving as cost-effective and simple models of nervous system electrostatic interactions and as in vitro drug release and model system for ECM transport studies.

scholarly journals Supramolecular protein-mediated assembly of brain extracellular matrix glycans

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1827 ◽  
Author(s):  
Anthony Tabet ◽  
Kamil Sokolowski ◽  
Jarrod Shilts ◽  
Marlous Kamp ◽  
Nina Warner ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Molecular Weight ◽  
Extracellular Matrix ◽  
Nervous System ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Electrostatic Interactions ◽  
Network Formation ◽  
Biological Tissues ◽  
Vis Spectroscopy

Background: Hyaluronic acid (HA) is the major component of the extracellular matrix in the central nervous system and the only supramolecular glycosaminoglycan. Much focus has been given to using this high molecular weight polysaccharide for tissue engineering applications. In the majority of cases, HA is covalently functionalized with moieties that can facilitate network formation through physical selfassembly, or photo-catalyzed covalent crosslinking as the polysaccharide does not gel on its own. However, these covalent crosslinks are not the driving force of HA self-assembly in biological tissues. Methods: Oscillatory rheology and dynamic light scattering were used to study albumin/HA structures. Dynamic light scattering and transmission electron microscopy were used to study albumin/chondroitin sulfate (CS) structures. UV-vis spectroscopy was used to study mass transfer of a hydrophilic small molecule into the albumin/HA/CS materials. Results: In this work we examine the intermolecular interactions of two major glycans found in the human brain, HA and the lower molecular weight CS , with the protein albumin. We report physiochemical properties of the resulting supramolecular micro- and nanomaterials. Albumin/HA mixtures formed supramolecular gels, and albumin/CS mixtures formed micro- and nanoparticles. We also summarize the concentrations of HA and CS found in various mammalian brains. Conclusions: Simple preparation and combination of commercially available charged biomacromolecules under short time-scales can result in interesting self-assembled materials with structures at the micron and nanometer length-scales. Such materials may have utility in serving as cost-effective and simple models of nervous system electrostatic interactions and as in vitro drug release and mass transfer quantification tools.

scholarly journals COMPLEXATION OF POLYETHYLENE-GLYCOL WITH THE SODIUM SALTS OF CITRIC AND SUCCINIC ACIDS IN THE AQUEOUS SOLUTIONS. STUDIES BY DYNAMIC LIGHT SCATTERING AND UV/VIS SPECTROPHOTOMETRY

2015 ◽  
Vol 11 (8) ◽  
pp. 3866-3872
Author(s):  
E.A. Masimov ◽  
Etibar Hummat Ismailov ◽  
S.Y. Odzhaqverdiyeva
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Aqueous Solutions ◽  
Polyethylene Glycols ◽  
Hydrodynamic Diameter ◽  
Absorption Bands ◽  
Sodium Salts ◽  
And Diffusion ◽  
Formation Of Complexes

Dynamic light scattering (DLS) method in combination with the UV/VIS spectrophotometry is used to study the interaction of polyethylene- glycols with a molecular weight  6000 ( PEG6000 ) with sodium salts of citric and succinic acids in aqueous solutions. The values of density, viscosity, refractive and diffusion indexes, the values of the hydrodynamic diameter, wavelength electronic absorption bands for PEG6000 aqueous solutions, their mixtures with succinic and citric acids are determined. It was shown that depending on the composition of the solutions the values of hydrodynamic diameter for aqueous solutions containing 1-5 wt.% PEG6000 and their mixtures with succinic and citric acids (~ 1 wt%) ranges from 3.6 to 5.2 nm. It is assumed that the formation of complexes with the sizes  that are within the above range is due to the features of interaction  and the structure of the complexes formed in solution.

scholarly journals Detection Limits of DLS and UV-Vis Spectroscopy in Characterization of Polydisperse Nanoparticles Colloids

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Emilia Tomaszewska ◽  
Katarzyna Soliwoda ◽  
Kinga Kadziola ◽  
Beata Tkacz-Szczesna ◽  
Grzegorz Celichowski ◽  
...  
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Point Of View ◽  
Spectroscopy Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
The One

Dynamic light scattering is a method that depends on the interaction of light with particles. This method can be used for measurements of narrow particle size distributions especially in the range of 2–500 nm. Sample polydispersity can distort the results, and we could not see the real populations of particles because big particles presented in the sample can screen smaller ones. Although the theory and mathematical basics of DLS technique are already well known, little has been done to determine its limits experimentally. The size and size distribution of artificially prepared polydisperse silver nanoparticles (NPs) colloids were studied using dynamic light scattering (DLS) and ultraviolet-visible (UV-Vis) spectroscopy. Polydisperse colloids were prepared based on the mixture of chemically synthesized monodisperse colloids well characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), DLS, and UV-Vis spectroscopy. Analysis of the DLS results obtained for polydisperse colloids reveals that several percent of the volume content of bigger NPs could screen completely the presence of smaller ones. The presented results could be extremely important from nanoparticles metrology point of view and should help to understand experimental data especially for the one who works with DLS and/or UV-Vis only.

A Simple Method for Synthesis of PbS Nanoparticles Using 2-Mercaptoethanol as the Capping Agent

2012 ◽  
Vol 31 (6) ◽  
pp. 723-725 ◽  
Author(s):  
Gholamreza Nabiyouni ◽  
Parviz Boroojerdian ◽  
Kambiz Hedayati ◽  
Davood Ghanbari
Keyword(s):  
Electron Microscopy ◽  
Electronic Absorption Spectra ◽  
Blue Shift ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Sulfur Source ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Vis Spectroscopy

AbstractLead sulfide nanoparticles were synthesized at room temperature via a simple chemical reaction. In this synthesis, 2-mercaptoethanolwas used as the capping agent and sodium sulfide was used as a sulfur source. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy Electron microscopy study showed that without using a capping agent the bulk PbS is obtained, while adding the mercaptoethanol leads to production of nanoparticles. We found that the electronic absorption spectra as well as the particle sizes depend on the used capping agents. Two exitonic peaks with a large blue shift were observed when mercaptoethanol was used.

Quantitative investigations of the aggregation behaviour of hydrophobic anilino squaraine dyes through UV/vis spectroscopy and dynamic light scattering

1999 ◽  
Vol 77 (5-6) ◽  
pp. 903-912 ◽  
Author(s):  
James Wojtyk ◽  
Andrew McKerrow ◽  
Peter Kazmaier ◽  
Erwin Buncel
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Particle Diameter ◽  
Water Medium ◽  
Thermodynamic Control ◽  
Squaraine Dyes ◽  
Water Solvent ◽  
Aggregation Behaviour ◽  
Vis Spectroscopy ◽  
J Aggregates

In continuing studies of the aggregation behaviour of squaraine dyes in DMSO-water mixtures, we have examined a series of symmetrical anilino-based squaraines with increasing N-alkyl chain length (n-butyl, n-octyl, and n-dodecyl). The aggregation behaviour was assessed through UV/vis spectroscopic and Dynamic Light Scattering (DLS) studies with quantitative interpretation based on exciton theory. This class of N-alkyl squaraines forms two distinct solution aggregates, Type J and Type H, depending on the composition of the DMSO-water medium. DLS measurement of the aggregates in the Type J and Type H morphologies showed that (i) the particle diameter increased with increasing hydrophobicity; (ii) DMSO has a large effect on the aggregate size; (iii) Type J aggregates are of equal dimensions with Type H aggregates. Moreover, even though as the DMSO-water solvent composition is varied the UV/vis spectra of Type H and Type J aggregates remained unchanged, the number of molecules comprising each aggregate varies widely. It is proposed that the dynamic conversion (J →> H) results from intramolecular reorganization of individual molecules within the aggregate. Quantification of aggregation through DLS has further developed the "kinetic" versus "thermodynamic" control model of dye aggregation.Key words: squaraine, dynamic light scattering, DMSO-water mixtures, self-assembly, kinetic/thermodynamic control.

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