Investigating Protein Diffusivities in Diluted Hyaluronic Acid Solutions Using Dynamic Light Scattering

2022 ◽  
Author(s):  
Hao Lou ◽  
Michael Hageman

This study aimed to investigate the diffusivities of lysozyme (LYS), ovalbumin (OVA), and hyaluronic acid (HA) in buffered solvents using dynamic light scattering (DLS). For protein/solvent and HA/solvent binary systems,...

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Leah Shaffer ◽  
Ray von Wandruszka

Humic acids in aqueous solution demonstrate inverse temperature-solubility relationships when solution conditions are manipulated to reduce coulombic repulsion among the humic polyanions. These effects were followed by dynamic light scattering (DLS) measurements of the resulting aggregates, as well as the addition of a polarity sensitive fluorescent probe (pyrene). The humic solutions could be primed for temperature induced clouding by carefully lowering the pH to a point where hydration effects became dominant. The exact value of the cloud point (CP) was a function of both pH and humate concentration. The CPs mostly lay in the range 50–90°C, but DLS showed that temperature induced aggregation proceeded from approximately 30°C onward. Similar effects could be achieved by adding multivalent cations at concentrations below those which cause spontaneous precipitation. The declouding of clouded humate solutions could be affected by lowering the temperature combined with mechanical agitation to disentangle the humic polymers.


2018 ◽  
Author(s):  
Andrea Dodero ◽  
Rhodri Williams ◽  
Simona Gagliardi ◽  
Silvia Vicini ◽  
Marina Alloisio ◽  
...  

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1827
Author(s):  
Anthony Tabet ◽  
June Y. Park ◽  
Jarrod Shilts ◽  
Kamil Sokolowski ◽  
Vijay K. Rana ◽  
...  

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.


2010 ◽  
Vol 1277 ◽  
Author(s):  
F. Carvajal ◽  
J. G. Alvarez ◽  
E.R. Macías ◽  
V.V.A. Fernández ◽  
E. Robles-Avila ◽  
...  

Linear rheological behavior and Microrheology measurements of sodium salt calf-thymus DNA aqueous solutions as a function of concentration are reported here. The microrheological behavior was obtained by a combination of experimental techniques: mechanical Rheometry and Dynamic light scattering (DLS). The viscoelastic properties of DNA in water as a function of concentration were performed at 20 °C and rheological and microrhelogical curves were performed. The result indicated that for concentrations lower than the entanglement concentration (Ce) the system exhibits a predominantly viscous behavior, whereas for higher concentrations exhibits a predominantly elastic behavior. The plateau modulus (G0) and the zero complex viscosity () follow a power law concentration dependence of the form: and , respectively The microrheology results overlap perfectly in a single line with the mechanical rheology results, extending the time resolution to faster breathing modes


2019 ◽  
Vol 10 ◽  
pp. 2594-2608 ◽  
Author(s):  
Arianna Gennari ◽  
Julio M Rios de la Rosa ◽  
Erwin Hohn ◽  
Maria Pelliccia ◽  
Enrique Lallana ◽  
...  

This study is about linking preparative processes of nanoparticles with the morphology of the nanoparticles and with their efficiency in delivering payloads intracellularly. The nanoparticles are composed of hyaluronic acid (HA) and chitosan; the former can address a nanoparticle to cell surface receptors such as CD44, the second allows both for entrapment of nucleic acids and for an endosomolytic activity that facilitates their liberation in the cytoplasm. Here, we have systematically compared nanoparticles prepared either A) through a two-step process based on intermediate (template) particles produced via ionotropic gelation of chitosan with triphosphate (TPP), which are then incubated with HA, or B) through direct polyelectrolyte complexation of chitosan and HA. Here we demonstrate that HA is capable to quantitatively replace TPP in the template process and significant aggregation takes place during the TPP–HA exchange. The templated chitosan/HA nanoparticles therefore have a mildly larger size (measured by dynamic light scattering alone or by field flow fractionation coupled to static or dynamic light scattering), and above all a higher aspect ratio (R g/R H) and a lower fractal dimension. We then compared the kinetics of uptake and the (antiluciferase) siRNA delivery performance in murine RAW 264.7 macrophages and in human HCT-116 colorectal tumor cells. The preparative method (and therefore the internal particle morphology) had little effect on the uptake kinetics and no statistically relevant influence on silencing (templated particles often showing a lower silencing). Cell-specific factors, on the contrary, overwhelmingly determined the efficacy of the carriers, with, e.g., those containing low-MW chitosan performing better in macrophages and those with high-MW chitosan in HCT-116.


MRS Advances ◽  
2019 ◽  
Vol 5 (17) ◽  
pp. 891-897 ◽  
Author(s):  
Ferenc Horkay ◽  
Peter J. Basser ◽  
Erik Geissler

ABSTRACTSmall angle neutron scattering (SANS) and dynamic light scattering (DLS) measurements were made on near physiological solutions of a bottlebrush shape polyelectrolyte, aggrecan. Aggrecan is a biologically important molecule whose complexes with hyaluronic acid (HA) provide the osmotic resistance of cartilage. We have investigated the effect of complexation of aggrecan with HA on the structure and dynamic properties of aggrecan solutions. SANS reveals that the supramolecular structure of aggrecan assemblies is only marginally affected by the HA. DLS indicates that the dynamic response of the aggrecan-HA complex is slower than that of the corresponding aggrecan solution. However, addition of calcium ions slightly increases the relaxation rate of the autocorrelation function of the aggrecan solution.


F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1827
Author(s):  
Anthony Tabet ◽  
June Y. Park ◽  
Jarrod Shilts ◽  
Kamil Sokolowski ◽  
Vijay K. Rana ◽  
...  

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.


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