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

Identification of Reliable Reference Genes for the Expression of <i>Hydrangea macrophylla</i> ‘Bailmer’ and ‘Duro’ Sepal Color

Hydrangea spp. is renowned for its variety of color changes in its developmental stage and before and after aluminum treatment. We analyzed gene expression in hydrangeas sepals to study the causes of color change. The accuracy of quantitative RT-qPCR analysis depends on the reliability of reference genes. We selected reference genes for hydrangea of varying cultivars, at different developmental stages, and in aluminum treatment groups. We chose ‘Bailmer’ and ‘Duro’ as subject species. We selected eight candidate genes, all of which were ranked by geNorm, NormFinder, BestKeeper, and RefFinder. CCR, NHX1, and LODX were used to verify the exactitude of reference genes. According to the ranking result of RefFinder, the top-ranked reference genes in each group were different; the top four candidate reference genes in each group mostly included EF1-β, RPL34, GADPH, and RPL10. EF1-β and RPL34 ranked top in the ‘all materials’ group, and their expression trends, obtained from the analysis of CCR, NHX1, and LODX, were consistent. From the results, we gather that EF1-β and RPL34 can be used as reference genes to quantify target gene expression. In this study, we screened for reference genes in hydrangeas to provide a technical basis for hydrangea sepal formation and transformation for further experiments

Identification of Seven Key Structural Genes in the Anthocyanin Biosynthesis Pathway in Sepals of <em>Hydrangea macrophylla</em>

Under specific cultivation conditions, the sepal color of Hydrangea macrophylla (H. macrophylla) changes from red to blue due to the complexation of aluminum ions (Al3+), delphinidin 3-glucoside, and copigments. However, this phenomenon cannot occur in all cultivars despite the presence of sufficient Al3+ and copigments. To explore the mechanism of sepal bluing in H. macrophylla, there is an urgent need to study the molecular regulation of the anthocyanin biosynthesis pathway. However, the key structural genes, other than CHS, regulating anthocyanin biosynthesis in the sepals of H. macrophylla have not been identified. In this study, based on full-length transcriptome data from H.macrophylla ‘Bailmer’, the key structural genes regulating anthocyanin biosynthesis in the sepals of H. macrophylla were isolated and investigated. Ultimately, seven key structural genes, HmCHS1, HmCHI, HmF3H1, HmF3′H1, HmF3′5′H, HmDFR2, and HmANS3, were demonstrated to show high expression levels in colored sepals. The expression levels of these seven genes increased gradually with the development of sepals and were highest in the full-bloom stage. The trend of gene expression was consistent with the trend of anthocyanin contents. It was concluded that the seven selected genes were involved in anthocyanin biosynthesis in the sepals of H. macrophylla. The full-length sequence data have been deposited into the NCBI Sequence Read Archive (SRA) with accession number PRJNA849710. This study lays a good foundation for the further elucidation of the molecular mechanism of sepal coloration in H. macrophylla

Hierarchical Image-based and Polygon-based Rendering for Large-Scale Visualizations

this paper we study the relative advantages and disadvantages of these approaches to learn how best to combine these competing techniques towards a hierarchical, robust, and hybrid rendering system for large data visualizatio

Looking through the imaging perspective: the importance of imaging necrosis in glioma diagnosis and prognostic prediction – single centre experience

The aim of the study was to investigate the diagnostic value of imaging necrosis (Imnecrosis) in grading, predict the genotype and prognosis of gliomas, and further assess tumor necrosis by dynamic contrast-enhanced MR perfusion imaging (DCE-MRI)