Poly Sucrose Research Articles

Factors influencing the stability of the polysucrose/alumina system

The influence of such factors as polymer concentration (10–800 ppm), pH of the solution (3–9), and ionic strength of the background electrolyte (0.001–0.1) and the presence of surfactants (SDS, CTAB, TX-100) on the stability of the colloidal suspensions alumina/polysucrose were measured spectrophotometrically. The obtained results, discussed together with the adsorption, the surface charge density, and the surface tension data, showed that the measured suspensions are unstable and flocculate quite easily. Although due to the fact that polysucrose (PS) considered to be neutral proved to be slightly negatively charged, there is a chance to control the stability using the abovementioned factors. The most effective way to obtain stable Al2O3/PS suspensions was the addition of SDS to the system. Because of the competitive adsorption between PS and sodium dodecyl sulfate (SDS) at the alumina surface, the larger number of free macromolecules of PS is present in the bulk solution, what leads to the depletion stabilization process. The other examined factors such as the polymer concentration, pH of the solution, and the ionic strength of the electrolyte have minor influence on the stability of the Al2O3/PS suspensions. The obtained results create new possibilities in the fields of functionalized materials such as adsorbents and catalysts.

Synthesis of polysucrose-based nanoparticles by a one-step method

A set of novel water-soluble polysucrose-based nanoparticles were prepared by a one-step self-assembly method using soluble polysucrose (PS) and acrylic acid (AA) as materials, ceric ammonium nitrate (CAN) as initiator and methylene-bisacrylamide (MBA) as crosslinker. Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance and scanning electron microscopy were utilized to characterize the structure and morphology. The results indicated the dimensions of the nanoparticles increased from 209.7nm to 293nm, and the polydispersity index (PDI) decreased, with the increase of AA content from 6.61 to 29.20mmol/g, while the content of PS (2.5g), the other components (RMI=220 and RMC=35) and experimental conditions were kept constant. The dimensions of nanoparticles increased from 244nm to 281nm and the PDI increased with the increase of initiator content from 0.04 to 0.12mmol/g, while the content of AA (2.1g), the other components (RSM=0.25 and RMC=35) and experimental conditions were kept constant.

Preparation and characterization of crosslinked polysucrose microspheres

A series of novel crosslinked polysucrose (PS) microspheres were prepared by a two-stage polymerization. A soluble (linear and/or comb) polysucrose was firstly synthesized by solution polymerization of sucrose and epichlorohydrin (EP); then the crosslinked polysucrose microspheres were prepared by reversed suspension polymerization of soluble PS with EP in chlorobenzene containing Span 80. The characterization by OM and SEM indicates that these spherical beads in diameters with the range from 250 to 450 μm have smooth surface. The hydrated and dry densities, equilibrium water contents, and hydroxyl loadings of PS microspheres were investigated. The equilibrium water content values of these microspheres changed from 79.6% to 94.1%, and the hydroxyl contents were 15.5–19.0 m mol/g dependent on the crosslinking degrees.

Permeation of polysucrose 15000 across the human nasal mucosa in vivo.

Studies of the nasal permeation of small molecules (< 1000 Da) have yielded important information about the integrity of the human airway mucosa in health and disease. In this study, we used a much larger tracer molecule, polysucrose (PS) 15,000 (approx. 14,700 Da), to predict the mucosal permeation of inhalational allergens. PS 15,000 (50 mg/ml; 15 ml), with or without a detergent type of permeation enhancer (dioctyl sodium sulfosuccinate 10 mg/ml), was maintained for 15 min in one nasal cavity of 12 healthy nonatopic subjects by employment of a nasal-pool device. Permeation as determined by the 24-h urine recovery of PS (micro-ELISA analysis assay) was expressed as percentage of nasal instillate. Mean baseline permeation was 0.044% (range 0.009-0.250%). In the presence of the detergent, permeation increased to 0.600% (range 0.007-2.260%) (P < 0.01). After oral intake of 750 mg of PS 15,000 (50 micrograms/ml; 15 ml), the 24-h urinary recovery was 0.013% (range 0.004-0.023%). Our study thus demonstrates a measurable baseline permeation of PS 15,000, an elevated permeation rate in the presence of an epithelium-damaging detergent molecule, and a negligible permeation by the oral route. These properties support the utility of PS 15,000 as a nasal airway permeation tracer. Its size further suggests that its permeation may reflect mucosal perviousness to many allergens.

Detection of naproxen-induced intestinal permeability change may be facilitated by adding a standardized meal but not by forming marker ratios.

We recently compared the intestinal permeability markers polysucrose (PS) 15,000, 51Cr-ethylenediaminetetraacetic acid (EDTA), and 14C-mannitol in healthy humans. We have now studied the ability of these markers to show non-steroidal anti-inflammatory drug (NSAID)-induced intestinal damage, with special regard to the possibility of improving discrimination versus healthy intestine by using a hyperosmolar test solution, adding a standardized liquid meal, calculating paracellular/ transcellular marker excretion ratios, or correcting excretion values for urinary volume. Seventeen healthy volunteers ingested a solution containing PS 15,000, 51Cr-EDTA, and 14C-mannitol before and after 1 week of naproxen intake, the solution being isosmolar, hyperosmolar, or isosmolar and followed by a standardized liquid meal. Fractional urinary excretion of the substances was measured over 0-4 h, 4-8 h, and 8-12 h. The excretion of the paracellular permeability markers PS 15,000 and 51Cr-EDTA increased after NSAID pretreatment, whereas that of the transcellular marker 14C-mannitol was unaffected. A standardized liquid meal reduced test variability for all markers and tended to improve differentiation between diseased and healthy intestine. A hyperosmolar test solution tended to improve differentiation for 51Cr-EDTA but not for PS 15,000. Calculating a paracellular/transcellular ratio or correcting excretion values for urinary volume did not improve the differentiation. A standardized liquid meal may improve the capacity of permeability tests to distinguish between healthy and NSAID-damaged intestine.

Chemical and physiological properties of polysucrose, a new marker of intestinal permeability to macromolecules.

To measure intestinal absorption of macromolecules we have developed a new technique employing synthetic polysucrose polymers as probe molecules. Polysucrose (PS) is water-soluble, nontoxic, resistant to intestinal enzymes, spherical and can be produced with a molecular weight distribution that relates to the size of many normal food proteins. Normally, a very small fraction of large molecules passes the exclusion barrier of the healthy intestine. Thus, quantification of resorbed macromolecules requires assays of high sensitivity. For detection of PS in various biological fluids, micro-ELISAs have been established. PS with a mean molecular weight of 14,700 daltons (PS 15,000) is rapidly excreted into the urine. Twenty-one healthy volunteers who orally ingested 1 g of this preparation showed a 12-hour urine excretion of 0.018% (interquartile range 0.014-0.022).