Evaluation of genipin-crosslinked chitosan hydrogels as a potential carrier for silver sulfadiazine nanocrystals

In the present study genipin crosslinked chitosan (CHI) hydrogels, which had been constructed and reported in our previous studies (Lei Gao, et al. Colloids Surf. B Biointerfaces. 2014, 117: 398), were further evaluated for their advantage as a carrier for silver sulfadiazine (AgSD) nanocrystal systems. Firstly, AgSD nanocrystals with a mean particle size of 289 nm were prepared by wet milling method and encapsulated into genipin crosslinked CHI hydrogels. AgSD nanocrystals displayed a uniform distribution and very good physical stability in the hydrogel network. Swelling-dependent release pattern was found for AgSD nanocrystals from hydrogels and the release profile could be well fitted with Peppas equation. When AgSD nanocrystals were encapsulated in hydrogels their fibroblast cytotoxicity decreased markedly, and their antibacterial effects against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were still comparable to unencapsulated AgSD nanocrystals. In vivo evaluation in excision and burn cutaneous wound models in mice showed that AgSD nanocrystal hydrogels markedly decreased the expression of inflammatory cytokine IL-6, but increased the levels of growth factors VEGF-A and TGF-β1. Histopathologically, the wounds treated by hydrogels containing AgSD nanocrystals showed the best healing state compared with commercial AgSD cream, hydrogels containing AgSD bulk powders and blank hydrogels. The wounds treated by AgSD nanocrystal hydrogels were dominated by marked fibroblast proliferation, new blood vessels and thick regenerated epithelial layer. Sirius Red staining assay indicated that AgSD nanocrystal hydrogels resulted in more collagen deposition characterized by a large proportion of type I fibers. Our study suggested that genipin-crosslinked CHI hydrogel was a potential carrier for local antibacterial nanomedicines

Evaluation of genipin-crosslinked chitosan hydrogels as a potential carrier for silver sulfadiazine nanocrystals

This paper was accepted for publication in the journal Colloids and Surfaces B: Biointerfaces and the definitive published version is available at http://dx.doi.org/10.1016/j.colsurfb.2016.06.016In the present study genipin crosslinked chitosan (CHI) hydrogels, which had been constructed and reported in our previous studies (Lei Gao, et al. Colloids Surf. B Biointerfaces. 2014, 117: 398), were further evaluated for their advantage as a carrier for silver sulfadiazine (AgSD) nanocrystal systems. Firstly, AgSD nanocrystals with a mean particle size of 289 nm were prepared by wet milling method and encapsulated into genipin crosslinked CHI hydrogels. AgSD nanocrystals displayed a uniform distribution and very good physical stability in the hydrogel network. Swelling-dependent release pattern was found for AgSD nanocrystals from hydrogels and the release profile could be well fitted with Peppas equation. When AgSD nanocrystals were encapsulated in hydrogels their fibroblast cytotoxicity decreased markedly, and their antibacterial effects against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were still comparable to unencapsulated AgSD nanocrystals. In vivo evaluation in excision and burn cutaneous wound models in mice showed that AgSD nanocrystal hydrogels markedly decreased the expression of inflammatory cytokine IL-6, but increased the levels of growth factors VEGF-A and TGF-β1. Histopathologically, the wounds treated by hydrogels containing AgSD nanocrystals showed the best healing state compared with commercial AgSD cream, hydrogels containing AgSD bulk powders and blank hydrogels. The wounds treated by AgSD nanocrystal hydrogels were dominated by marked fibroblast proliferation, new blood vessels and thick regenerated epithelial layer. Sirius Red staining assay indicated that AgSD nanocrystal hydrogels resulted in more collagen deposition characterized by a large proportion of type I fibers. Our study suggested that genipin-crosslinked CHI hydrogel was a potential carrier for local antibacterial nanomedicines

Success Factors for Supporting Intercultural Engagement of Employees towards Sustainability

Abstract: The goal of this thesis is to contribute to the overall progress of society towards sustainability by supporting the engagement of employees of multinational organizations. By first identifying unique aspects of sustainability that are important for engagement and aspects of national culture that affect receptivity to sustainability messages, the authors were able to make informed selections of success factors contributing to intercultural sustainability engagement. Within these categories, specific strategies and actions leading to successful engagement were identified, based on interviews and survey results from experienced sustainability practitioners and intercultural management experts, as well as an extensive literature review. The further selection and refinement of these led to the development of a capacity building tool to help sustainability practitioners address cultural differences when working to engage employees of multinational organizations in [email protected], [email protected], [email protected]</p

Optimization of Ultrasonic-assisted Extraction of Fatty Acids in Seeds of Brucea Javanica (L.) Merr. from Different Sources and Simultaneous Analysis Using High-Performance Liquid Chromatography with Charged Aerosol Detection

Our research aimed to optimize the oil extraction process and determine the fatty acids in Brucea javanica (L.) Merr. seeds. The extraction technology was optimized using response surface methodology. A Box-Behnken design was employed to investigate the effects of three independent variables on an ultrasonic-assisted extraction technique, namely, sonication time (X1: 20–40 min), liquid–solid ratio (X2: 16:1 mL/g–24:1 mL/g), and ethanol concentration (X3: 90%–100%). The optimum conditions of sonication time, liquid–solid ratio, and ethanol concentration were 40 min, 24:1 mL/g, and 100%, respectively. The content of fatty acids and the oil yield were 14.64 mg/g and 16.87%, respectively, which match well with the predicted models. The optimum number of extraction times was eventually identified as two. A new rapid method for the qualitative and quantitative analysis of the fatty acids of B. javanica (L.) Merr. seed oil using HPLC with a charged aerosol detector was described. The fatty acid contents of 14 batches of B. javanica (L.) Merr. seed oil were determined, and the relevance and difference were analyzed by fingerprint analysis. The fingerprint has five common peaks, and the similarity was greater than 0.991. HPLC analysis represents a specialized and rational approach for the quality identification and comprehensive evaluation of B. javanica (L.) Merr. seed oils

Time-Course Investigation of Small Molecule Metabolites in MAP-Stored Red Blood Cells Using UPLC-QTOF-MS

Red blood cells (RBCs) are routinely stored for 35 to 42 days in most countries. During storage, RBCs undergo biochemical and biophysical changes known as RBC storage lesion, which is influenced by alternative storage additive solutions (ASs). Metabolomic studies have been completed on RBCs stored in a number of ASs, including SAGM, AS-1, AS-3, AS-5, AS-7, PAGGGM, and MAP. However, the reported metabolome analysis of laboratory-made MAP-stored RBCs was mainly focused on the time-dependent alterations in glycolytic intermediates during storage. In this study, we investigated the time-course of alterations in various small molecule metabolites in RBCs stored in commercially used MAP for 49 days using ultra-high performance liquid chromatography quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS). These alterations indicated that RBC storage lesion is related to multiple pathways including glycolysis, pentose phosphate pathway, glutathione homeostasis, and purine metabolism. Thus, our findings might be useful for understanding the complexity of metabolic mechanisms of RBCs in vitro aging and encourage the deployment of systems biology methods to blood products in transfusion medicine

Genome-Wide Identification, Characterization, and Expression Analysis of the <i>DMP</i> Gene Family in Pepper (<i>Capsicum annuum</i> L.)

Members of DOMAIN OF UNKNOWN FUNCTION 679 membrane proteins (DMPs) have the DUF679 domain, which plays an important role in the process of plant fertilization. In this study, bioinformatics methods were used to identify and analyze the DMP gene family in pepper. The location of the expression of the DMP gene family was explored according to the transient expression of Nicotiana benthamiana, and its expression patterns in different tissues and abiotic stress treatments were analyzed by qRT-PCR. A total of 17 CaDMP genes were identified from the three capsicum varieties, and sub-cellular localization prediction showed that CaDMPs were located on the cell membrane. Phylogenetic analysis showed that CaDMP5 in subgroup Ⅳ was highly homologous with haploid induction genes in Arabidopsis and maize, and its expression level in reproductive organs was significantly higher than that in other tissues, suggesting that CaDMP5 could be a candidate gene for haploid induction in pepper. The expression of CaDMPs increased to varying degrees after different stress treatments, indicating that the DMP gene plays an important role in plant growth and development. The CaDMP gene family was systematically analyzed in this study, which provided preliminary insights for the further research of Capsicum haploid breeding

Legacy polychlorinated organic pollutants in the sediment of the Great Lakes

Legacy, organic pollutants, including polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), naphthalenes (PCNs), and diphenyl ethers (PCDEs) were quantified in sediments of the Laurentian Great Lakes of North American. A total of 40 cores (939 core segments) and 198 Ponar surface grab samples were collected from the five Great Lakes between 2010 and 2014. Median concentrations in Ponar grab samples were 8.4, 0.27, 0.05, 0.19 and 0.01 ng/g dry weight (dw) for total-PCBs, Sigma(7)PCDDs, 10PcDFs, Sigma(2)PcNs, and Sigma 7PCDEs, respectively. By using Geographic Information Systems Analysis with the inverse distance weight (IDW) interpretation of the spatial distribution of the chemical inventory at coring sites, total mass loads in the five lakes combined were estimated to be 511, 15.3, 5.3, 20.7 and 2.9 t for total-PCBs, Sigma(7)PCDDs, Sigma(7)PCDFs, Sigma(12)PCNs, and Sigma 7PCDEs, respectively. Patterns of spatial distributions revealed pollution hotspots and provided evidence for historical local sources. Concentrations of residues in Ponar grabs and inventories at coring sites, when normalized to concentrations of organic carbon, exhibited statistically significantly correlations with latitude and longitude of the sampling sites for all five chemical groups. At most coring sites, concentrations have been decreasing towards the sediment surface. At locations relatively close to known or suspected sources, estimated half-times for all classes of chemicals were approximately 20 years. The declining trends of PCDDs and PCDFs were unclear at some locations, suggesting the presence of currently active emission sources. (C) 2018 International Association for Great Lakes Research. Published by Elsevier B.V. All rights reserved

Illite K-Ar Dating of the Leibo Fault Zone, Southeastern Margin of the Tibetan Plateau:Implications for the Quasi-Synchronous Far-Field Tectonic Response to the India-Asia Collision

Whether tectonic strain from the early stage India-Asia collision has synchronously affected the far-field margin of the Tibetan Plateau is crucial for understanding plateau deformation and growth processes. However, direct evidence for early far-field deformation remains scarce. Utilizing illite K-Ar dating of three fault gouge samples, we established the faulting history of the Leibo fault zone (LFZ) at the southeastern margin of the Tibetan Plateau (SEMTP). Consistent authigenic illite ages of 52 ± 2, 54 ± 12 and 55 ± 6 Ma suggest the reactivated thrust faulting of the LFZ in the Early Cenozoic. Positioned ∼700 km east of the collisional boundary and at the intersection of three blocks with distinct lithospheric rheology in strength/viscosity, this event suggests a quasi-synchronous far-field tectonic response in the SEMTP to the India-Asia collision.</p

An optimized LC-MS/MS method for determination of HYNIC-3PRGD

HYNIC-3PRGD2 is used to prepare a new 99mTc-radiolabeled tracer. HYNIC-3PRGD2, which has a high binding affinity for the integrin αvβ3due to its special structure, has become a promising tumor imaging agent for diagnosis and monitor of the clinical response to therapeutic effects of anti-tumor agents. Here, we developed and validated a method for determination of HYNIC-3PRGD2 concentration in rat plasma using ultra-high performance liquid chromatography-tandem mass spectrometry system. Following sample extraction by methanol precipitation, satisfactory separation through chromatography was achieved on an hydrophilic reverse-phase C18 column AQ (2.1 mm × 100 mm, 2.7 μm) at a flow rate of 0.2 mL·min-1 with an gradient elution using mobile phase consisting of ultrapure water and acetonitrile fortified with 0.1% formic acid respectively. The calibration curve was developed over a linear range of 3.125-100 ng·mL-1 with the lower limit of quantification of 3.125 ng·mL-1. The HYNIC-3PRGD2 and its internal standard c(RGDfK)(RK5) were detected and quantified with the multiple reaction monitoring (MRM) mode on a triple-quadrupole tandem mass spectrometer. This method was successfully validated and applied for pharmacokinetic evaluation of HYNIC-3PRGD2 during pre-clinical experiments