Biological and bioactivity assessment of dextran nanocomposite hydrogel for bone regeneration.

Insufficient biological and bioactive properties of dextran hydrogels limit their applications as promising scaffolds for tissue engineering. We developed nanocomposite dextran hydrogels comprised of bioactive glass (nBGC: 64% SiO2, 31% CaO, 5% P2O5) nanoparticles with an average particle size of 77 nm using a chemical crosslinking of dextran chains to form 3D hydrogel networks. In the current study; bioactivity of the obtained nanocomposite hydrogels was evaluated through the formation of apatite crystal structures after the incubation in simulated body fluid (SBF) at various submersion periods and nBGC content. The scanning electron microscopy (SEM) micrographs represented an enhanced hydroxyapatite formation on the cross section of nanocomposite comprising of nBGC content from 2 to 8 (% by wt). Biomineralization results of Dex-8 (% by wt) composite during 7, 14 and 28 days immersion indicated the apatite layer formation and the growth of apatite crystal size on the surface and cross section of the nanocomposite. Moreover, MTT assessments indicated that human osteosarcoma cells (SaOS-2) were able to adhere and spread within the dextran hydrogels reinforced with the bioactive glass nanoparticles. With regard to enhanced bioactivity and biocompatibility, the developed dextran-nBGC hydrogel could be considered as a suitable candidate for bone tissue engineering application.

Investigation of Obesity-Alleviation Effect of Eurycoma longifolia on Mice Fed with a High-Fat Diet through Metabolomics Revealed Enhanced Decomposition and Inhibition of Accumulation of Lipids.

The metabolic and bioactivity effects of Eurycoma longifolia (Eucalyptus longifolia) in obesity treatment were studied in mice fed with a high-fat diet using a metabolomics approach. Aqueous extracts of E. longifolia were obtained via grinding, dissolving, and freeze-drying. The hepatic steatosis effect of E. longifolia was characterized by hematoxylin and eosin histological staining. External performance of the obesity-alleviation effect was monitored by measuring body and food weight. In addition, the metabolomics analysis of the E. longifolia-mice interaction system was performed using the established platform combining liquid chromatography-tandem mass spectrometry with statistical analysis. The presence and spatial distribution patterns of differential molecules were further evaluated through desorption electrospray ionization-mass spectrometry imaging. The results showed that E. longifolia played a vital role in downregulating lipid accumulation (especially triacylglycerols) and fatty acids biosynthesis together with enhanced lipid decomposition and healing in Bagg albino mice. During such a process, E. longifolia mainly induced metabolomic alterations of amino acids, organic acids, phospholipids, and glycerolipids. Moreover, under the experimental concentrations, E. longifolia induced more fluctuations of aqueous-soluble metabolites in the plasma and lipids in the liver than in the kidneys. This study provides an advanced alternative to traditional E. longifolia-based studies for evaluating the metabolic effects and bioactivity of E. longifolia through metabolomics technology, revealing potential technological improvement and clinical application.

Biological Evaluation for Quality Control of Water Extract of Qingjin Huatantang Based on Phagocytic and Secretory Functions of Macrophages / 中国实验方剂学杂志

Objective:To establish a method for evaluating the biological activity of water extract lyophilized powder of Qingjin Huatantang based on the phagocytic and secretory functions of macrophages， and to control the quality of this formula from the biological activity level. Method:The phagocytic and inflammation models of RAW264.7 macrophages were established， the inhibition rates of water extract lyophilized powder of Qingjin Huatantang on interleukin-6 （IL-6） secretion and phagocytic index of neutral red of RAW264.7 macrophages were chosen as indicators to investigate the biological activity of Qingjin Huatantang， and the biological limit was searched. Result:The optimal inoculation density of RAW264.7 macrophages was 3×10⁵ pcs/mL， and the concentration of lipopolysaccharide （LPS） was 1 mg·L^-1 after treatment for 24 h. When the concentration was 500 mg·L^-1， water extract lyophilized powder of Qingjin Huatantang had no toxicity and no obvious promotion effect on the proliferation of RAW264.7 macrophages， and at this concentration， the phagocytosis of RAW264.7 macrophages for neutral red was significantly promoted， the phagocytic index was >113%. In addition， the lyophilized powder had a significant and stable inhibitory effect on IL-6 secretion of RAW264.7 macrophages induced by LPS， the inhibitory rate was >45%. Conclusion:Combined with the anti-inflammatory and immunomodulatory effects of Qingjin Huatantang， this study establishes an <italic>in vitro </italic>biological limit method for evaluating the quality of water extract of Qingjin Huatantang based on the phagocytic and secretory functions of RAW264.7 macrophages， and 500 mg·L^-1 was confirmed as the limit concentration. Under the limit concentration， Qingjin Huatantang water extract can significantly promote the phagocytic index of macrophages or significantly inhibit the secretion of IL-6 of RAW264.7 macrophages induced by LPS， which can be judged as qualified.

Recovery of high-value and scarce resources from biological wastewater treatment: Sulfated polysaccharides.

Recovering materials with high value and increasing market demand from sewage and/or sludge is becoming more attractive than recovering traditional resources such as nutrients and biogas. Sulfated polysaccharides (SPs) are valuable and scarce raw materials that can only be produced from marine algae and a few types of animal tissues. This study evaluated if SPs are present in activated sludge obtained from saline sewage with a high level of sulfates present. The presence of SPs-containing extracellular polymeric substances (EPS) was confirmed and quantified for both sludge from lab-scale reactors and full-scale plants for the first time. SPs in the sludge of a lab-scale reactor operated under alternating aerobic/anoxic conditions with 500 mg/L sulfate in the influent (which is typical of Hong Kong saline sewage) reached 342.8 ±â€¯0.3% mg/gVSS, and sludge taken from a full-scale saline wastewater treatment plant (WWTP) contained 418.1 ±â€¯0.4% mg/gVSS of SPs. Purity of the extracted SPs was comparable to that of commercial industrial-grade products. Key bioactivities of SPs (i.e. fucoidan, carrageenan and heparin), namely anti-angiogenesis, anticoagulant and antioxidant, were confirmed after extraction and purification. Interestingly, operating conditions had a strong influence on the contents and types of SPs synthesized in sludge as well as its bioactivities. Although the detailed synthetic pathways of SPs in activated sludge remain unclear, the current study has made a first attempt to recover a high-value scarce resource from biological wastewater treatment.

Hazard identification of cis/trans-zearalenone through the looking-glass.

Among the food-related health issues, the presence of contaminants has a prominent role, due to the wide range of exogenous compounds that can occur in food commodities and to their large differences in structure and biological activity. A comprehensive assessment of the related risk is thus actually demanding in terms of time and facilities involved. In this context, the use of computational strategies can be an effective choice for supporting the hazard identification procedure at the early stage. In this work, we focused on the food contaminant zearalenone by comparing the trans and cis isomers, respectively the well-known mycoestrogen and its still largely understudied isomer. We estimated the possible effects exerted by human metabolism on the xenoestrogenicity of cis-ZEN by using a validated in silico strategy based on docking simulations and rescoring procedures. Similarly, the exploitation of the most promising enzymatic detoxifying routes designed for trans-ZEN - which relies on the enzyme lactono hydrolase from Clonostachys rosea - has been assessed for the cis-isomer as well. Our results showed that both isomers can act as functional analogues with respect to xenoestrogenic activity, and several cis-ZEN metabolites with high biological potential have been identified. On the contrary, in spite of the high degree of structural analogy, the cis isomer showed a pattern of interaction with the degrading enzyme in stark contrast with that observed for trans-ZEN. For these reasons, the outcomes presented herein strongly support the inclusion of cis-ZEN in further studies of occurrence, metabolism and bioactivity assessment, and suggest the need for a dedicated handling for the cis isomer in risk assessment studies.