Rational design of porous starch/hyaluronic acid composites for hemostasis.

Effective hemorrhage control is pivotal for decreasing the trauma death both in civilian and military but has proven to be dauntingly challenging, especially for solid viscera and artery trauma. Here we report the fabrication of a novel starch-based hemostat, sodium trimethaphosphate (STMP)-crosslinked starch/hyaluronic acid (HA) (ScSH) porous composites. Aiming at hemostatic potential, physicochemical properties, cytocompatibility, hemocompatibility, histocompatibility and hemostatic performance of ScSH composites have been studied. As it turned out, the incorporation of HA greatly improved the water absorption capacity and hemostatic performance of ScSH composites. In addition, the composites with a non-toxic crosslinker exhibited non-cytotoxicity, low hemolysis ratio (0.97%) and favorable histocompatibility. Meanwhile, the composites performed exceptionally well in blood clotting of superficial injury, solid viscera and artery trauma and displayed similar hemostatic efficacy to commercialized hemostat (Quickclean® particles). Unambiguously, these encouraging results highlighted potential of our materials to be used as hemostats and made the approach, constructing porous starch/HA composites, a promising strategy to accelerate further development of hemostatic agents applied both in vivo and in vitro.

Histone Modifications Regulate Chromatin Compartmentalization by Contributing to a Phase Separation Mechanism.

Eukaryotic chromosomes contain compartments of various functions, which are marked by and enriched with specific histone modifications. However, the molecular mechanisms by which these histone marks function in chromosome compartmentalization are poorly understood. Constitutive heterochromatin is a largely silent chromosome compartment characterized in part by H3K9me2 and 3. Here, we show that heterochromatin protein 1 (HP1), an H3K9me2 and 3 "reader," interacts with SUV39H1, an H3K9me2 and 3 "writer," and with TRIM28, an abundant HP1 scaffolding protein, to form complexes with increased multivalent engagement of H3K9me2 and 3-modified chromatin. H3K9me2 and 3-marked nucleosomal arrays and associated complexes undergo phase separation to form macromolecule-enriched liquid droplets. The droplets are reminiscent of heterochromatin as they are highly dense chromatin-containing structures that are resistant to DNase and exclude the general transcription factor TFIIB. Our data suggest a general mechanism by which histone marks regulate chromosome compartmentalization by promoting phase separation.

Optimization of subcritical water extraction of polysaccharides from Grifola frondosa using response surface methodology.

BACKGROUND: This research is among the few that has been conducted on the feasibility of subcritical water extraction (SWE) as a rapid and efficient extraction tool for polysaccharides. OBJECTIVE: The aim of the study was to extractand optimize the parameter conditions of SWE of polysaccharides from Grifola frondosa using response surface methodology. MATERIALS AND METHODS: In the study, SWEwas applied to extractbioactive compounds from G. frondosa. A preliminary analysis was made on the physical properties and content determination of extracts using SWE and hot water extraction (HWE). Analysis of the sample residues and antioxidant activities of the polysaccharides extracted by SWE and HWE were then evaluated. RESULTS: THE OPTIMAL EXTRACTION CONDITIONS INCLUDE: extraction temperature of 210°C, extraction time of 43.65 min and the ratio of water to raw material of 26.15:1. Under these optimal conditions, the experimental yield of the polysaccharides (25.1 ± 0.3%) corresponded with the mean value predicted by the model and two times more than the mean value obtained by the traditional HWE. The antioxidant activities of polysaccharides extracted by SWE were generally higher than those extracted by HWE. From the study, the SWE technology could be a time-saving, high yield, and bioactive technique for production of polysaccharides.

Enhanced anti-diabetic activity of a combination of chromium(III) malate complex and propolis and its acute oral toxicity evaluation.

In order to obtain the additional benefit of anti-diabetic activity and protective effects of liver injury for diabetes, the anti-diabetic effect and acute oral toxicity of a combination of chromium(III) malate complex (Cr(2)(LMA)(3)) and propolis were assessed. The anti-diabetic activity of the combination of the Cr(2)LMA(3) and propolis was compared with Cr(2)(LMA)(3) and propolis alone in alloxan-induced diabetic mice by daily oral gavage for a period of 2 weeks. Acute oral toxicity of the combination of the Cr(2)LMA(3) and propolis was tested using ICR mice at the dose of 1.0-5.0 g/kg body mass by a single oral gavage and observed for a period of 2 weeks. The results of the anti-diabetic activity of the combination from the aspects of blood glucose level, liver glycogen level, and the activities of aspartate transaminase, alanine transaminase, and alkaline phosphatase indicated that the increased anti-diabetic activity and the protective efficacy of liver injury for diabetes were observed. In acute toxicity study, LD(50) (median lethal dose) value for the combination was greater than 5.0 g/kg body mass. The combination of Cr(2)LMA(3) and propolis might represent the nutritional supplement with potential therapeutic value to control blood glucose and exhibit protective efficacy of liver injury for diabetes and non-toxicity in acute toxicity.