Search

Silk and silk fibroin, the biomaterial from nature, nowadays are being widely utilized in many cutting-edge micro/nanodevices/systems via advanced micro/nanofabrication techniques. Herein, for the first time to our knowledge, we report aqueous multiphoton lithography of diversiform-regenerated-silk-fibroin-centric inks using noncontact and maskless femtosecond laser direct writing (FsLDW). Initially, silk fibroin was FsLDW-crosslinked into arbitrary two/three-dimensional micro/nanostructures with good elastic properties merely using proper photosensitizers. More interestingly, silk/metal composite micro/nanodevices with multidimension-controllable metal content can be FsLDW-customized through laser-induced simultaneous fibroin oxidation/crosslinking and metal photoreduction using the simplest silk/Ag+ or silk/[AuCl4]− aqueous resists. Noticeably, during FsLDW, fibroin functions as biological reductant and matrix, while metal ions act as the oxidant. A FsLDW-fabricated prototyping silk/Ag microelectrode exhibited 104-Ω−1 m−1-scale adjustable electric conductivity. This work not only provides a powerful development to silk micro/nanoprocessing techniques but also creates a novel way to fabricate multifunctional metal/biomacromolecule complex micro/nanodevices for applications such as micro/nanoscale mechanical and electrical bioengineering and biosystems. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the cytotoxic and apoptotic effects of bishydroxycoumarin (BHC) against human glioma cells and to study their mode of action., Methods: Three cells were used in the experiments. MTT and LDH assays were used to assess the cytotoxic effects of BHC while an in vitro wound healing assay was used to study the effect of BHC on cell migration. Fluorescence microscopy and annexin V-FITC assay were used to study the cellular morphology and apoptotic effects while flow cytometry in combination with propidium iodide (PI) were used to study cell cycle arrest induced by BHC., Results: BHC induced substantial and dose-dependent cytotoxic effects against all three cell lines with U87MG cell line being most susceptible. BHC also inhibited cell migration and induced characteristic morphological changes including chromatin condensation, nuclear shrinkage which increased with increasing dose of BHC. The apoptotic cell population (both early and late apoptotic cells) increased with increasing dose of BHC which also induced substantial G0/G1 cell cycle growth arrest in U87MG cells., Conclusion: This study provides help to elucidate the translational potential of the in vitro results to be used for further in vivo studies on human glioma using animal or human subjects. The mechanistic pathway studied in this report could be helpful in explaining the mode of action of these classes of natural products.

Aneuploidy is a common characteristic of human solid tumors. It has been proposed that a defect of the spindle assembly checkpoint (SAC) generates aneuploidy and might facilitate tumorigenesis. However, a direct link between the SAC proteins and tumorigenesis has not yet been elucidated. Here, we demonstrate the association of the SAC protein MAD1 with the RNA polymerase II complex and its role in gene expression. Furthermore, MAD1 binds to the E-cadherin promoter region. Knockdown of endogenous MAD1 by siRNA reduces E-cadherin expression and enhances the migration ability of non-metastatic breast cancer cells, indicating that reduced MAD1 expression is a new potential diagnostic symptom of tumor metastasis.

By testing the less critical product areas of two different materials, this paper verifies the test method described in ISO 22612.

The essay introduces the study on the performance monitoring tests for the resistance to wet bacterial penetration about surgical gowns and surgical drapes in accordance with ISO 22610.