Search results for "Dextrans"
showing 10 items of 67 documents
Comparative study of Zorbax Bio Series GF 250 and GF 450 and TSK-Gel 3000 SW and SWXL columns in size-exclusion chromatography of proteins.
1988
Abstract A reduction of the mean particle diameter of silica-based packings in the size-exclusion chromatography (SEC) of proteins to about 5 μm generates the expected increase in column plate number over the traditional 10 μm SEC columns, as demonstrated for the Zorbax Bio Series GF 250 and GF 450 and TSK-Gel 3000 SWXL columns. The slightly lower column efficiency of the TSK-Gel 3000 SWXL compared with the GF 250 column is compensated by the fact that the phase ratio of the 3000 SWXL column is higher by a factor of two. Hence both columns show nearly the same peak capacity of about 20–30. When the ionic strength of the eluent was changed by varying the salt concentration, the elution volum…
Calorimetric and structural investigation of the interaction between bovine serum albumin and high molecular weight dextran in water.
2005
This work studies specific interactions between a small globular protein and a highly flexible, branched polysaccharide using differential scanning calorimetry (DSC), circular dichroism (CD), fluorescence, and turbidimetry measurements. It uses the system water/bovine serum albumin (BSA)/dextran (D 2000) as a model. Dextran molecules are able to form interpolymeric complexes with BSA in water at both low and high temperatures if the polysaccharide is in excess and if the protein exists in its associated state. It leads to a partial destabilization of the secondary and tertiary structures of the protein and an additional exposure of the hydrophobic tryptophan residues to the surface of globu…
Phase behavior of aqueous solutions of bovine serum albumin in the presence of dextran, at rest, and under shear.
2006
The demixing conditions for aqueous solutions of bovine serum albumin (BSA, fraction V) and for joint solutions of BSA plus dextran (DEX, M(w) = 2000 kg/mol) were determined by turbidimetric measurements as a function of composition, temperature, and shear rate. Aqueous solutions of BSA phase separate upon heating. Within the region of BSA concentrations between 0.05 and 32 wt %, the demixing temperature, T1, falls from ca. 65 degrees C to an almost constant value of 45 degrees C. Adding DEX to the BSA solutions reduces the homogeneous region of the mixture drastically where the amount of DEX required to lower T1 to 25 degrees C decreases rapidly as the concentration of BSA is raised. Exper…
Quantitative contributions of IgG, IgM and C3 to erythrophagocytosis and rosette formation by peritoneal macrophages, and anti-opsonin activity of de…
1976
In vitro phagocytosis by guinea pig peritoneal macrophages of immune complexes (EA) was shown to be dependent on IgG antibody in a dose-dependent fashion. C3b enhanced phagocytosis of EA at limited IgG antibody concentrations only. When IgM antibody was used for sensitization of sheep red blood cells (SRBC), phagocytosis and rosette formation did not occur in the absence of bound C3. The polyanion, dextran sulfate 500 (DS), was shown to depress both rosette formation and phagocytosis of EAIgG, C1423 and EAIgMC1423, as well as immune adherence of human group 0 erythrocytes and hemolytic activity of C3. This effect of DS was seen only when it was actually present in the incubation medium.
Biodegradable hydrogels obtained by photocrosslinking of dextran and polyaspartamide derivatives
2003
The functionalization of dextran with glycidyl methacrylate (GMA) leads to the formation of a derivative that generates hydrogels for irradiation at 365nm. The effects of various polymer concentrations and irradiation times on the yield and the properties of the obtained hydrogels are reported. The networks have been characterized by FT-IR spectra, dimensional analysis and swelling measurements carried out at different pH values. In vitro studies suggest that all samples undergo a partial chemical hydrolysis, whereas the incubation with dextranases causes a total degradation whose rate depends on the degree of crosslinking. In addition, aqueous solutions of functionalized dextran have been …
Size-isolation of superparamagnetic iron oxide nanoparticles improves MRI, MPI and hyperthermia performance.
2020
Journal of nanobiotechnology 18, 22 (2020). doi:10.1186/s12951-020-0580-1
Double stimuli-responsive polysaccharide block copolymers as green macrosurfactants for near-infrared photodynamic therapy
2019
The NIR absorbing photosensitizer phthalocyanine zinc (PC(Zn)) was stabilized in aqueous media as water-dispersible nanoparticles with a reduction- and pH-responsive full polysaccharide block copolymer. A cellular uptake and also photo switchable intracellular activity of the cargo upon irradiation at wavelengths in the near infrared region were shown. The block copolymer was synthesized by applying a copper-free click strategy based on a thiol exchange reaction, creating an amphiphilic double-stimuli-responsive mixed disulfide. The dual-sensitive polysaccharide micelles represent a non-toxic and biodegradable green macrosurfactant for the delivery of phthalocyanine zinc. By encapsulation i…
Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses
2015
36 p.-7 fig.-1 tab.-1 fig. supl.
Septal complex of the telencephalon of lizards: III. Efferent connections and general discussion.
1998
The projections of the septum of the lizard Podarcis hispanica (Lacertidae) were studied by combining retrograde and anterograde neuroanatomical tracing. The results confirm the classification of septal nuclei into three main divisions. The nuclei composing the central septal division (anterior, lateral, medial, dorsolateral, and ventrolateral nuclei) displayed differential projections to the basal telencephalon, preoptic and anterior hypothalamus, lateral hypothalamic area, dorsal hypothalamus, mammillary complex, dorsomedial anterior thalamus, ventral tegmental area, interpeduncular nucleus, raphe nucleus, torus semicircularis pars laminaris, reptilian A8 nucleus/ substantia nigra and cen…
In vivo confocal laser laparoscopy allows real time subsurface microscopy in animal models of liver disease.
2007
Background/Aims Histopathology is essential in the diagnostic workup of most liver diseases. However, biopsy sampling might carry risks, is subject to sampling error, and does not provide dynamic tissue imaging. Therefore a newly developed miniaturised confocal probe was evaluated for in vivo microscopic imaging in rodent models of human liver diseases. Methods The handheld laparoscopy probe used a 488nm single line laser for fluorophore excitation. Optical slice thickness was 7μm, lateral resolution 0.7μm. Imaging depth was 0–250μm below the tissue surface. Imaging using different fluorescent staining protocols was performed in healthy mice, IFNγ- and IL-12-induced hepatitis, after bile du…