Fabrication and Characterization of Hydrocolloid Dressing with Silk Fibroin Nanoparticles for Wound Healing

Hydrocolloid dressings have been developed for many types of wound healing. In particular, dressing is a critical component in the successful recover of burn injuries, which causes a great number of people to not only suffer from physical but also psychological and economic anguish each year. Additionally, silk fibroin is the safest material for tissue engineering due to biocompatibility. In this study, we fabricated hydrocolloid dressings incorporating silk fibroin nanoparticles to enhance the efficacy of hydrocolloid dressing and then use this silk fibroin nanoparticle hydrocolloid dressing (SFNHD) in animal models to treat burn wounds. The structures and properties of SFNHD were characterized using tensile strength and Cell Counting Kit-8 assay. The results indicated the structural stability and the cellular biocompatibility of the hydrocolloid dressing suggesting that SFNHD can be applied to the treatment of wounds. To demonstrate the capacity of a silk fibroin hydrocolloid dressing to treat burn wounds, we compared SFNHD to gauze and Neoderm®, a commercially available dressing. This study clearly demonstrated accelerated wound healing with greater wound structural integrity and minimal wound size after treatment with SFNHD. These observations indicate that SFNHD may be an improvement upon current standard dressings such as Gauze and Neoderm® for burn wounds.

xCITED2 Induces Neural Genes in Animal Cap Explants of Xenopus Embryos

Neural tissue is arisen from presumptive ectoderm via inhibition of bone morphogenetic protein (BMP) signaling during Xenopus early development. Previous studies demonstrate that ectopic expression of dominant negative BMP4 receptor (DNBR) produces neural tissue in animal cap explants (AC) and also increases the expression level of various genes involved in neurogenesis. To investigate detail mechanism of neurogenesis in transcriptional level, we analyzed RNAs increased by DNBR using total RNA sequencing analysis and identified several candidate genes. Among them, xCITED2 (Xenopus CBP/p300-interacting transcription activator) was induced 4.6 fold by DNBR and preferentially expressed in neural tissues at tadpole stage. Ectopic expression of xCITED2 induced anterior neural genes without mesoderm induction and reduced BMP downstream genes, an eye specific marker and posterior neural marker. Taken together, these results suggest that xCITED2 may have a role in the differentiation of anterior neural tissue during Xenopus early development.

Isolation of Early Neurogenesis Genes with Xenopus cDNA Microarray / 한국실험동물학회지

Neurogenesis is the process that develops neuroectoderm from ectoderm. Bone morphogenetic protein (BMP) inhibition in ectodermal cells is necessary and sufficient for neurogenesis in Xenopus embryos. To isolate genes involved in early neurogenesis, Xenous Affymetrix gene chips representing 14,400 genes were analyzed in early stage of neuroectodermal cells that were produced by inhibition of BMP signaling with overexpression of a dominant-negative receptor. We identified 265 candidate genes including 107 ESTs which were newly expressed during the early neurogenesis by blocking BMP signaling. The candidates of 10 ESTs were selected and examined for upregulation in neuroectoderm. Five EST genes were confirmed to be upregulated in neuroectoderm and examined for time-dependent expression patterns in intact embryos. Two EST genes were cloned and identified as a homology of CYP26c (Xl.1946.1.A1_at) and Kielin containing VWC domain (Xl.15853.1.A1_at). One of them, CYP26c, was further characterized for its transcriptional regulation and role of anterior-posterior patterning during neurogenesis. Taken together, we analyzed and characterized genes expressed in early neurogenesis. The results suggest that neurogenesis by inhibition of BMP provides useful system to isolate genes involved in early events of neurogenesis during early vertebrate embryogenesis.