Characterization of oxidative damage induced by nanoparticles via mechanism-driven machine learning approaches

Impact of microplastics on plant physiology: A meta-analysis of dose, particle size, and crop type interactions in agricultural ecosystems

The increasing prevalence of plastic pollution has led to widespread environmental concerns, particularly with microplastics (MPs) that persist in various ecosystems. As MPs accumulate in terrestrial environments, their potential impact on plant health and agricultural productivity has become a growing area of focus. This study presents a comprehensive meta-analysis evaluating the effects of MPs on plant physiological and biochemical parameters, synthesizing data from 37 studies comprising 2886 observations. Our findings indicate that MPs significantly decrease plant biomass by 13 % (95 % CI: 7-19 %) and chlorophyll content by 28 % (95 % CI: 23-34 %), impairing crop growth and quality. Notably, higher doses and smaller MP particle sizes exert more pronounced inhibitory effects, particularly on root activity and biomass, while larger MPs predominantly damage plant roots. Furthermore, MPs were found to significantly increase oxidative stress in plants, evidenced by a 20 % rise in oxidative damage (95 % CI: 15-25 %) and a 14 % increase in antioxidant capacity (95 % CI: 8-19 %). This study highlights intricate interactions between MP type, particle size, dose, and plant species, with particle size having a greater impact than dose. This study emphasizes the importance of accounting for crop diversity and environmental factors to fully elucidate the potential risks posed by MP pollution to agricultural ecosystems.

Machine learning based predictive analysis of DNA cleavage induced by diverse nanomaterials

DNA cleavage by nanomaterials has the potential to be utilized as an innovative tool for gene editing. Numerous nanomaterials exhibiting DNA cleavage properties have been identified and cataloged. Yet, the exploitation of property data through data-driven machine-learning approaches remains unexplored. A database was developed, compiling thirty distinctive characteristics, encompassing physical and chemical properties, as well as experimental conditions of nanomaterials that have demonstrated DNA cleavage capability such as in articles published over the past two decades. The DNA cleavage effect and efficiency of nanomaterials were predicted using machine learning algorithms such as support vector machines, deep neural networks, and random forest, and a classification accuracy of 0.93 for the cleavage effect was achieved. Moreover, the potential of utilizing larger datasets to enhance the predictive capacity of models was discussed. The findings indicate the feasibility of predicting nanomaterial properties based on experimental data. Evaluating the performance and effectiveness of the machine learning models trained using the existing data can furnish valuable insights for future materials research endeavors, especially for the design of DNA cleavage with specific sites.

How denitrifiers defense ciprofloxacin: Insights from intracellular and extracellular stress response

Overuse of antibiotics has led to their existence in nitrogen-containing water. The impacts of antibiotics on bio-denitrification and the metabolic response of denitrifiers to antibiotics are unclear. We systematically analyzed the effect of ciprofloxacin (CIP) on bio-denitrification and found that 5 mg/L CIP greatly inhibited denitrification with a model denitrifier (Paracoccus denitrificans). Nitrate reduction decreased by 32.89 % and nitrous oxide emission increased by 75.53 %. The balance analysis of carbon and nitrogen metabolism during denitrification showed that CIP exposure blocked electron transfer and reduced the flow of substrate metabolism used for denitrification. Proteomics results showed that CIP exposure induced denitrifiers to use the pentose phosphate pathway more for substrate metabolism. This caused a substrate preference to generate NADPH to prevent cellular damage rather than NADH for denitrification. Notably, despite denitrifiers having antioxidant defenses, they could not completely prevent oxidative damage caused by CIP exposure. The effect of CIP exposure on denitrifiers after removal of extracellular polymeric substances (EPS) demonstrated that EPS around denitrifiers formed a barrier against CIP. Fluorescence and infrared spectroscopy revealed that the binding effect of proteins in EPS to CIP prevented damage. This study shows that denitrifiers resist antibiotic stress through different intracellular and extracellular defense strategies.

Doping zinc oxide and titanium dioxide nanoparticles with gold induces additional oxidative stress, membrane damage, and neurotoxicity in Mytilus galloprovincialis: Results from a laboratory bioassay

BACKGROUND

While previous studies have provided insights into the effects of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles (NPs) on aquatic organisms, there is still a substantial amount of information lacking about the possible effects of their doped counterparts. The goal of the current work was to address this gap by examining Mytilus galloprovincialis reaction to exposure to doped and undoped nanoparticles.

METHODS

Two concentrations (50 or 100 µg/L) of undoped ZnO and TiO2 NPs, as well as their gold (Au) doped counterparts, were applied on mussels for 14 days, and the effects on biomarkers activities in digestive glands and gills were assessed by spectrophotometry.

RESULTS

The NPs were quasi-spherical in shape (below 100 nm), stable in seawater, and with no aggregation for both doped and undoped forms. Analytical results using inductively coupled plasma atomic emission spectroscopy indicated the uptake of NPs in mussels. Furthermore, it was found that biometal dyshomeostasis could occur following NP treatment and that doping the NPs aggravated this response. At the biochemical level, exposure to undoped NPs caused membrane damage, neurotoxic effect, and changes in the activities in the gills and digestive glands of superoxide dismutase, catalase, and glutathione-S-transferase, in a concentration and organ-dependent manner.

CONCLUSION

Doping ZnO NPs and TiO2NPs with Au induced additional oxidative stress, membrane damage, and neurotoxicity in mussels.

Ecological Risks of Zinc Oxide Nanoparticles for Early Life Stages of Obscure Puffer (Takifugu obscurus)

Nanoparticles of zinc oxide (ZnO NPs) are extensively used in various applications, and their widespread use leads to their environmental presence, particularly in wastewater treatment plant effluents, rivers, and soil. This study focuses on the obscure puffer, Takifugu obscurus, an economically important fish in China, aiming to assess the toxic effects of ZnO NPs on its early life stages, emphasizing the need for understanding the ecological implications of ZnO NP exposure in aquatic environments. Exposure during the hatching stage resulted in a significant decrease in hatching rates, with embryos displaying surface coating at higher ZnO NP concentrations. Newly hatched larvae experienced deformities, and post-hatching exposure led to pronounced reductions in survival rates, particularly with higher ZnO NP concentrations. Two-month-old juveniles exposed to increasing ZnO NP concentrations exhibited a consistent decline in survival rates, emphasizing concentration-dependent adverse effects. Biochemical analyses revealed elevated malondialdehyde (MDA) levels and decreased glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activities in various tissues, indicating oxidative stress. This study underscores the ecological risks of ZnO NP contamination in aquatic environments, emphasizing the need for careful consideration of nanoparticle exposure in aquatic ecosystems.