Yi Liu,Mengen Kang,Yuzhu Weng,Yuanyuan Ding,Xue Bai
Recent studies have reported that nanoparticles (NPs) released into the aquatic environment may interact with persistent organic pollutants such as brominated flame retardants, whereas the environmental processes and toxicological impacts induced by such binary NPs require further specification. This study investigated the ultrastructural damage of Chlorella vulgaris triggered by exposure to zinc oxide (ZnO) NPs, tetrabromobisphenol A (TBBPA), ZnO–TBBPA, and ZnO–TBBPA–humic acid (HA), clarified the uptake and distribution of ZnO NPs in cells, and explored the physiological toxicity and tolerance mechanism. The results demonstrated that ZnO NPs induced irregular morphology in algal cells, and the disruption of the cellular ultrastructure by binary ZnO–TBBPA was also extremely severe due to the excessive uptake of ZnO NPs, which resulted in strong oxidative stress responses. In particular, the accumulation of reactive oxygen species further exacerbated the reduction of total chlorophyll content and algal density. Moreover, the cluster heat map and correlation analysis revealed that superoxide dismutase activity played a critical role in alleviating lipid peroxidation damage and enhancing the tolerance of algal cells to the stress of binary ZnO NPs. More notably, the existence of HA intensified the dispersion stability of NP suspensions and significantly mitigated the synergistic toxicity of binary ZnO–TBBPA. This study provides new insights into the environmental behavior and biological impacts of binary NPs in the natural environment.
Advanced oxidation processes (AOPs) are highly efficient for the removal of antibiotics from water. The activation of hydrogen peroxide (H 2 O 2 ) by ultraviolet (UV) has garnered increasing attention. This study describes the enhanced photochemical degradation of emerging contaminants in water using a UV-activated calcium peroxide (UV/CaO 2 ) system, wherein CaO 2 can gently produce H 2 O 2 when exposed to UV light . The UV/CaO 2 system can expeditiously and efficiently eradicate ciprofloxacin (CIP), in which hydroxyl radicals (•OH) and superoxide anions (O 2 •- ) played critical roles. The superlative rate constant was 0.024 min −1 at an optimal dosage of 0.1 g L −1 , which was a 16-fold increase over the rate of pure UV photolysis. The UV/CaO 2 system had an excellent defluorination capacity (80% within 60 min). Further, this technology was intensely evaluated over a wide range of pH for the removal of CIP, including H 2 O 2 yields, defluorination rates, as well as correlations with the reactive species generated during the reactions for numerical analysis. The UV/CaO 2 system had an excellent anti-interference capacity over a wide pH range. Three major degradation pathways were proposed for the degradation of CIP, together with predictions of the physiological toxicity of these transformation intermediates. This study provides strong technical support for the promotion of this UV/CaO 2 water treatment platform, as well as the decontamination and defluorination of water matrixes contaminated with fluoroquinolones.
Breast cancer is one of the most threatening cancers that poses a great risk to women's health . The anti-tumor drug doxorubicin (DOX) is one of commonly used drugs in the treatment of breast cancer. However, the cytotoxicity of DOX has always been an urgent challenge to be solved. In this study, we report an alternative drug delivery system delivering DOX for reducing its physiological toxicity by using the yeast β-glucan particle (YGP) with a hollow and porous vesicle structure. Briefly, amino groups were grafted onto the surface of YGP with the silane coupling agent, then the oxidized hyaluronic acid (OHA) was attached by Schiff base reaction to get HA-modified YGP ( [email protected] =C-HA), finally DOX was encapsulated into [email protected] =C-HA to get DOX-loaded [email protected] =C-HA ( [email protected] =C-HA/DOX). In vitro release experiments exhibited the pH-responsive DOX release from [email protected] =C-HA/DOX. Cell experiments displayed that [email protected] =C-HA/DOX had good killing effect on both MCF-7 and 4T1 cells and could be internalized into these cells through CD44 receptors, showing targetability to cancer cells. Furthermore, [email protected] =C-HA/DOX could effectively inhibit tumor growth and reduce the physiological toxicity of DOX. Thus, the YGP-based vesicle provides an alternative strategy for lowering the physiological toxicity of DOX in the medical treatment of breast cancer.
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