Characterization and in vitro evaluation of chitosan/konjac glucomannan bilayer film as a wound dressing.

A novel bilayer film of chitosan and konjac glucomannan were prepared by the two-step casting technique. Blend films were also prepared to investigate the interactions between the two polymers in the interfacial region of the bilayer structure. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis showed that, unlike in the blends, the physicochemical properties of each biopolymer were preserved in the bilayer film. Differential scanning calorimetry and thermogravimetric analysis also indicated a good thermostability and miscibility for both polymers, probably due to strong hydrogen bonds between their polymer chains. Biological, mechanical and water vapor transmission tests showed a high biocompatibility, low cytotoxicity, and suitable mechanical and barrier properties of the bilayer films for wound dressing applications.

A novel glycocluster molecule prevents timothy-induced allergic airway inflammation in mice.

BACKGROUND: Allergen-specific immunotherapy (SIT) effectively alleviates type I allergic diseases characterized by T helper (Th)2-type immunity. Our recent studies have shown that a synthetic trivalent glycocluster, triacedimannose (TADM), suppresses the Th2-type allergic inflammation. The aim of this study was to compare TADM with two well-known adjuvants, unmethylated cytosine-phosphate-guanine oligodeoxynucleotide (CpG) and monophosphoryl lipid A (MPLA) in a grass allergen-induced chronic allergic inflammation model in mice. METHODS: Female BALB/c mice were intranasally sensitized with 50 µL of timothy grass pollen extract (TE) twice a week for a period of 15 weeks. Therapeutic intranasal treatments were then performed once a week after the tenth intranasal TE instillation using TADM (10 or 25 µg/50 µL), CpG-ODN (20 µg/50 µL) or MPLA (2 µg/50 µL). Groups of 9-10 animals per treatment were killed 24 hours after the last timothy dosage. Blood, bronchoalveolar lavage (BAL) fluids and lung biopsies were taken for subsequent analysis. RESULTS: When mice were repeatedly exposed to TE for 15 weeks, the number of eosinophils and lymphocytes increased in the BAL fluids. The eosinophil and lymphocyte counts decreased dose-dependently and were practically abolished in the mice treated with TADM. Treatments with MPLA or CpG significantly increased the numbers of neutrophils, while CpG nonsignificantly decreased eosinophilia compared to timothy exposure. CONCLUSIONS: A novel synthetic glycocluster molecule inhibited the development of grass-induced eosinophilic pulmonary inflammation in mice when administrated in the airways. This compound could be a candidate to be used either as an adjuvant in SIT or as a topical anti-inflammatory treatment.

Selenium incorporated guar gum nanoparticles safeguard mitochondrial bioenergetics during ischemia reperfusion injury in H9c2 cardiac cells.

The application of nanotechnology has created high impact in diagnosis and prognosis of various disorders including cardiovascular diseases. In the present study, we investigated the beneficial effect of selenium incorporated guar gum nanoparticles (SGG) compared to nascent selenium (Se) and guar gum nanoparticles (GGN) against ischemiareperfusion (IR) induced alterations in oxidative phosphorylation and energy metabolism in H9c2 cardiac cells. Ischemia and reperfusion were induced for 1h. The alterations in activities of various complexes (complex 1, II, III and IV) of mitochondrial electron transport chain (ETC), aconitase activity, oxygen consumption rate, and the ATP content were seen. The role of heat shock protein, hypoxia inducible factor-1α and atrial natriuretic factor (ANP) were also analyzed. Then the beneficial properties of various particles like Se, GGN and SGG were evaluated. Among these, SGG treatment (1 and 5ng) was found to be more beneficial compared to other particles. Overall results reveal that SGG nanoparticles are effective in protecting H9c2 cardiac cells from IR injury via improving the efficiency of ETC in H9c2 cells.

Acetylated Trivalent Mannobioses: Chemical Modification, Structural Elucidation, and Biological Evaluation.

People suffering from allergies can be treated with repeated injections of increasing amounts of a specific allergen. This type of specific immunotherapy is currently the only way to treat the underlying pathological immune response associated with an allergy. The approach can afford long-lasting protection, but the process takes 3-5 years, can produce allergic reactions, and in severe cases treatment is often aborted due to anaphylaxis. However, treatment can be optimized with the use of specific adjuvants that modify the immune response, its duration, and that increase the production of the correct type of antibodies. In the pursuit of such adjuvants, two new trivalent acetylated ß-(1→2)-linked mannobioses based on a previously discovered lead molecule were prepared. The new molecules, along with the previously developed lead, were investigated by rigorous NMR and molecular modeling experiments in order to elucidate their behavior and preferred conformations in solution. Furthermore, the molecules were subjected to a biological investigation in which their immunostimulatory properties were evaluated by assessing their effect on the production of TH 2-type cytokine interleukin-4 (IL-4) and Treg pro-inflammatory cytokine tumor necrosis factor (TNF). Treatment of peripheral mononuclear blood cell cultures from patients suffering from birch allergy with birch allergen Bet v induced a strong IL-4 response, whereas the same treatment together with the trivalent acetylated mannobioses caused significant suppression of the induced IL-4.

Preparation, structure and anticoagulant activity of a low molecular weight fraction produced by mild acid hydrolysis of sulfated rhamnan from Monostroma latissimum.

A low molecular weight fraction, designated LMWP, was prepared by mild acid hydrolysis of sulfated rhamnan from Monostroma latissimum and purified by anion-exchange and gel-permeation chromatography. Chemical and spectroscopic analyses showed that LMWP was mainly composed of rhamnose, and its molecular weight was about 33.6 kDa. The backbone of LMWP consists of 1,3-linked α-L-rhamnose units with partially sulfate groups at the C-2 position. Approximately 25% of 1,3-linked α-L-rhamnose units is substituted at C-2 by sulfated or non-sulfated 1,3-linked α-L-rhamnose and 1,2-linked α-L-rhamnose units. LMWP effectively prolonged clotting time as evaluated by the activated partial thromboplastin time assay and was a potent thrombin inhibitor mediated by heparin cofactor II. The investigation demonstrated that LMWP is a novel sulfated polysaccharide with anticoagulant activity.