Conductive Nanofibers-Enhanced Microfluidic Device for the Efficient Capture and Electrical Stimulation-Triggered Rapid Release of Circulating Tumor Cells.

The effective detection and release of circulating tumor cells (CTCs) are of great significance for cancer diagnosis and monitoring. The microfluidic technique has proved to be a promising method for CTCs isolation and subsequent analysis. However, complex micro-geometries or nanostructures were often constructed and functionalized to improve the capture efficiency, which limited the scale-up for high-throughput production and larger-scale clinical applications. Thus, we designed a simple conductive nanofiber chip (CNF-Chip)-embedded microfluidic device with a herringbone microchannel to achieve the efficient and specific capture and electrical stimulation-triggered rapid release of CTCs. Here, the most used epithelial cell adhesion molecule (EpCAM) was selected as the representative biomarker, and the EpCAM-positive cancer cells were mainly studied. Under the effects of the nanointerface formed by the nanofibers with a rough surface and the herringbone-based high-throughput microfluidic mixing, the local topographic interaction between target cells and nanofibrous substrate in the microfluidic was synergistically enhanced, and the capture efficiency for CTCs was further improved (more than 85%). After capture, the sensitive and rapid release of CTCs (release efficiency above 97%) could be conveniently achieved through the cleavage of the gold-sulfur bond by applying a low voltage (-1.2 V). The device was successfully used for the effective isolation of CTCs in clinical blood samples from cancer patients, indicating the great potential of this CNF-Chip-embedded microfluidic device in clinical applications.

Tumor Microenvironment-Inspired Glutathione-Responsive Three-Dimensional Fibrous Network for Efficient Trapping and Gentle Release of Circulating Tumor Cells.

Detection of circulating tumor cells (CTCs) is important for early cancer diagnosis, prediction of postoperative recurrence, and individualized treatment. However, it is still challenging to achieve efficient capture and gentle release of CTCs from the complex peripheral blood due to their rarity and fragility. Herein, inspired by the three-dimensional (3D) network structure and high glutathione (GSH) level of the tumor microenvironment (TME), a 3D stereo (3D-G@FTP) fibrous network is developed by combining the liquid-assisted electrospinning method, gas foaming technique, and metal-polyphenol coordination interactions to achieve efficient trapping and gentle release of CTCs. Compared with the traditional 2D@FTP fibrous scaffold, the 3D-G@FTP fibrous network could achieve higher capture efficiency (90.4% vs 78.5%) toward cancer cells in a shorter time (30 min vs 90 min). This platform showed superior capture performance toward heterogeneous cancer cells (HepG2, HCT116, HeLa, and A549) in an epithelial cell adhesion molecule (EpCAM)-independent manner. In addition, the captured cells with high cell viability (>90.0%) could be gently released under biologically friendly GSH stimulus. More importantly, the 3D-G@FTP fibrous network could sensitively detect 4-19 CTCs from six kinds of cancer patients' blood samples. We expect this TME-inspired 3D stereo fibrous network integrating efficient trapping, broad-spectrum recognition, and gentle release will promote the development of biomimetic devices for rare cell analysis.

Life-cycle exposure to BDE-47 results in thyroid endocrine disruption to adults and offsprings of zebrafish (Danio rerio).

2,2,4',4'-Tetrabromodi-phenyl ether (BDE-47) is predominantly concentrated in humans and wildlife and disturbs thyroid hormone homeostasis. The purpose of this study was to characterize the thyroid endocrine disruption induced by life-cycle exposure to BDE-47 in adults and offspring of zebrafish (Danio rerio). We exposed zebrafish embryos at the blastula stage to different concentrations of BDE-47 (1, 5, and 10µg/L). Exposure duration was 180days until fish reached adulthood. In F0 larvae, exposure decreased survival and increased malformations at 4 dpf. Thyroid hormone concentrations did not differ significantly between the F0 larvae and controls. All exposures significantly up-regulated expression of tshß, pa8, ugt1 and tg and down-regulated ttr. Significant up-regulation of dio2 and crh was observed in the 10µg/L BDE-47 group. There was no significant difference in the growth and somatic index between F0 adults and controls. BDE-47 (10µg/L) significantly decreased whole-body content of thyroxine (T4) but significantly increased triiodothyronine (T3) in both sexes. All exposures up-regulated expression of crh, tshß, pa8, ugt1 and tg and down-regulated ttr. Exposure to 10µg/L BDE-47 significantly up-regulated dio2 and ugt1 in both sexes. BDE-47 exposure (5 and 10µg/L) significantly increased the activity of pethoxy-resorufin-O-deethylase and UDP-glucuronosyl transferase. BDE-47 (10µg/L) significantly increased activity of ethoxy- and methoxy-resorufin-O-deethylase. In F1 offspring without continued BDE-47 (10µg/L) treatment, T4 significantly decreased and T3 increased. T4 was further decreased and T3 was further increased with continued BDE-47 treatment. Continued BDE-47 exposure decreased hatching and increased malformation compared with those without BDE-47 exposure. Expression of crh, tshß, dio2, pa8, ugt1 and tg was significantly up-regulated without BDE-47 exposure and with continued exposure. With continued BDE-47 exposure, dio1 was significantly up-regulated and ttr was significantly down-regulated. All the genes showed clear differences between continued exposure to 10µg/L BDE-47 and without BDE-47 exposure. These results suggest that parental exposure to BDE-47 results in thyroid endocrine disruption in adults and offspring.

Zinc oxide nanoparticles induce oxidative DNA damage and ROS-triggered mitochondria-mediated apoptosis in zebrafish embryos.

Zinc oxide nanoparticles (nano-ZnO) are one of the most important nanoparticles in the industry. The objectives of this study were (1) to investigate the effects of nano-ZnO on oxidative damage to DNA and on apoptosis in zebrafish (Danio rerio) embryos, and (2) to identify the underlying molecular mechanism affecting theapoptotic process. In addition to nano-ZnO, we also investigated the toxic effects of the Zn2+ ion. Zebrafish embryos were exposed to 10, 30, 60, 90, or 120mg/L nano-ZnO for 96h postfertilization. Nano-ZnO (at concentrations between 10 and 120mg/L) significantly reduced the rate of embryo hatching. Embryos/larvae exposed to 120mg/L nano-ZnO had significantly higher heart rates. Increased heart rates could be a physiological mechanism compensating for body hypoxia. Embryos/larvae exposed to nano-ZnO exhibited oxidative stress, due to an excessive generation of reactive oxygen species (ROS). Oxidative stress was evidenced by increased levels of superoxide dismutase, by increased lipid peroxidation, and by increased expression of genes related to the antioxidant defense system (sod1, cat, gpx1a, and pparα), which were altered at different degrees. Upon exposure to nano-ZnO, the percentage of apoptotic cells increased in a dose-dependent manner (0.41% to 4.21%). In addition, altered transcriptional regulation of pro-apoptotic genes (bax, puma, and apaf-1) and anti-apoptotic genes (bcl-2) provided further evidence of the activation of apoptosis. In this study, exposure of zebrafish embryos to nano-ZnO triggered an excessive production of ROS, which was followed by several phenomena: the up-regulation of p53, a reduction in the bcl-2/bax ratio,a reduction in the mitochondrial membrane potential (ψm), the release of cytochrome c into the cytosolic fraction, and the activation of caspases 9 and 3. Collectively, our data imply that nano-ZnO induce an excessive production of ROS which then activate the apoptosis pathway mediated by mitochondria and caspases.