Spherical shape-defined hollow UiO-66 metal-organic frameworks with superior incident photon scattering for enhanced photoelectrochemical H2 evolution

Transcriptomic investigation of NP toxicity on HepaRG spheroids

Metal nanoparticles (NPs) are commonly used nanomaterials, however concerns have been raised about their toxicity. Although a few studies have reported the toxicity of NPs on cells, they have generally been restricted to a limited variety of NPs, inappropriate cell lines, or culture methods. Thus, the adverse effects remain inadequately understood, necessitating further analysis. This study focuses on assessing the impacts of diverse NPs of varying materials and sizes on HepaRG spheroids to determine the genes that respond to acute NP toxicity. HepaRG cells, the most appropriate alternative to primary hepatocytes, were cultured in 3D spheroids to better mimic the cellular microenvironment of the liver. To elucidate the toxicity mechanisms of NPs on HepaRG spheroids, transcriptome analysis was conducted by using RNA sequencing (RNA-seq). Among all NPs, lowest and highest numbers of differentially expressed genes (DEGs) were found for 40 nm AuNP (118 genes) and InP/ZnS (1904 genes), respectively. Remarkably, processes such as drug metabolism, sensitivity to metal ions, oxidative stress, endothelial-mesenchymal transition (EMT) and apoptosis consistently exhibited significant enrichment across all NPs of different materials. Pathways related to stress responses of the cells such as the MAPK, p53 and mTOR pathways are found to be dysregulated upon exposure to various NPs. The genes that are common and unique between DEGs of different NPs were identified. These results provide novel insights into the toxicological mechanisms of NPs on HepaRG spheroids.

Micro-nano hierarchical urchin-like ZnO/Ag hollow sphere for SERS detection and photodegradation of antibiotics

Hollow urchin-like substrates have been widely interested in the field of surface-enhanced Raman scattering (SERS) and photocatalysis. However, most reported studies are simple nanoscale urchin-like substrate with limited light trapping range and complicated preparation process. In this paper, a simple and effective controllable synthesis strategy based on micro-nano hierarchical urchin-like ZnO/Ag hollow spheres was prepared. Compared with the 2D structure and solid spheres, the 3D urchin-like ZnO/Ag hollow sphere has higher laser utilization and more exposed specific surface area due to its special hollow structure, which resulted in excellent SERS and photocatalytic performance, and successfully realize the detection and photodegradation of antibiotics. The limited of detection of metronidazole can reach as low as 10-9 M, and degradation rate achieve 89 % within 120 min. The experimental and theoretical results confirm that the ZnO/Ag hollow spheres can be used in the development of ZnO heterostructure for the detection and degradation of antibiotics, which open new avenues for the development of novel ZnO-based substrate in SERS sensing and catalytic application to address environmental challenges.