Combined effects of different sizes of ZnO and ZIF-8 nanoparticles co-exposure with Cd2+ on HepG2 cells

Adsorption behavior of ZIF-67 to bisphenol compounds affects combined toxicity on Photobacterium phosphoreum

ZIF-67, as a typical MOF material, is considered a new type of high-potential adsorbent due to its ample surface area and tunable surface chemistry, which has the potential to interact with other contaminants in unforeseen ways, resulting in combined toxicity. To further elucidate this possibility, we chose typical bisphenol compound (BP) which is widely used in commercial manufacturing, to explore the combined toxicity with MOF. MOF showed a high adsorption capacity for BPAF (> 80 %) and the weakest adsorption capacity for BPA (< 10 %), and DFT confirmed the different interaction strengths of MOF for BPs. The difference in adsorption capacity for BPs resulted in different amounts of free BPs, contributing to combined toxicity. Based on flow cytometry and TEM, the results showed that membrane damage was reduced and the ability of ZIF-67 to enter the cell was decreased in the low-concentration ZIF-67 mixing group, and the ability of ZIF-67 to enter the cell was increased in the high-concentration ZIF-67 mixing group, and the membranes were severely damaged. RT-PCR and biochemical indicators measurements helped to explain the underlying toxicity mechanism. This study is of practical significance for the development of environmental guidelines for mixed contaminant effects and accurate risk assessments.

N-acetyl-L-cysteine attenuated the toxicity of ZIF-8 on EA.hy926 endothelial cells by wnt/β-catenin pathway

As kinds of porous crystalline compounds, zeolitic imidazolate frameworks (ZIFs) have been developed quickly and attracted considerable attention for use in nano drug delivery systems, which raised concerns about cardiovascular disorders. At the present, the cytotoxic mechanism of ZIFs in cardiovascular disorders was still unclear. Our experiment explored the toxicity of ZIF-8, a typical kind of ZIFs, on human EA.hy926 vascular endothelial cells. The cell viability, ROS formation, apoptosis level, inflammatory response level, wound healing ability and atherosclerosis-related indicators of EA.hy926 endothelial cells were analyzed after ZIF-8 treatment. Meanwhile, we evaluated the ability of antioxidant N-Acetyl-L-cysteine (NAC) to attenuate the toxicity of ZIF-8 on EA.hy926 endothelial cells. As results, NAC attenuated ROS formation, cell apoptosis, LDH formation and endothelial dysfunction caused by ZIF-8. As the Wnt/β-catenin pathway was involved in endothelial cell dysfunction, we also studied the expression level of β-catenin and LEF1 in ZIF-8 and/or NAC treated EA.hy926 cells. As expected, ZIF-8 increased the protein expressions of β-catenin and LEF1in the IC50 group, which was significantly inhibited by co-treatment with NAC. Taken together, this study could help improve our understanding about the mechanism of ZIF-8-induced endothelial cells injury and NAC had therapeutic potential in preventing ZIF-8-associated endothelial dysfunction by wnt/β-catenin pathway.

Single-cell ICP-MS to address the role of trace elements at a cellular level

The heterogeneity properties shown by cells or unicellular organisms have led to the development of analytical methods at the single-cell level. In this sense, considering the importance of trace elements in these biological systems, the inductively coupled plasma mass spectrometer (ICP-MS) configured for analyzing single cell has presented a high potential to assess the evaluation of elements in cells. Moreover, advances in instrumentation, such as coupling laser ablation to the tandem configuration (ICP-MS/MS), or alternative mass analyzers (ICP-SFMS and ICP-TOFMS), brought significant benefits, including sensitivity improvement, high-resolution imaging, and the cell fingerprint. From this perspective, the single-cell ICP-MS has been widely reported in studies involving many fields, from oncology to environmental research. Hence, it has contributed to finding important results, such as elucidating nanoparticle toxicity at the cellular level and vaccine development. Therefore, in this review, the theory of single-cell ICP-MS analysis is explored, and the applications in this field are pointed out. In addition, the instrumentation advances for single-cell ICP-MS are addressed.