Exploring the environmental factor fulvic acid attenuates the ecotoxicity of graphene oxide under food delivery exposure.

There is limited understanding of nanoparticle potential ecotoxicity, particularly regarding the influence of environmental factors that can be transferred through the food chain. Here, we assessed the transfer behavior and the ecotoxicity of commercially manufactured graphene oxide nano-materials (GO, <100 nm) in a food chain perspective spanning from Escherichia coli (E. coli) to Caenorhabditis elegans (C. elegans) under simulated environmental conditions. Our findings revealed that E. coli preyed upon GO, subsequently transferring it to C. elegans, with a discernible distribution of GO observed in the digestive system and reproductive system. Accumulated GO generated serious ecological consequences for the higher level of the food chain (C. elegans). More importantly, GO and the resulting injurious effects of germ cells could be transferred to the next generation, indicating that GO exposure could cause genetic damage across generations. Previous research has demonstrated that GO can induce degradation of both the inner and outer cell membranes of E. coli, which is then transmitted to C. elegans through the food chain. Additionally, fulvic acid (FA) possesses various functional groups that enable interaction with nanomaterials. Our findings indicated that these interactions could mitigate ecotoxicity caused by GO exposure via food delivery, and this approach could be extended to modify GO in a way that significantly reduced its toxic effects without compromising performance. These results highlighted how environmental factors could attenuate ecological risks associated with nanomaterial transmission through the food chain.

Cancer spheroids derived exosomes reveal more molecular features relevant to progressed cancer.

Cancer cell spheroids have been shown to be more physiologically relevant to native tumor tissue than monolayer 2D culture cells. Due to enhanced intercellular communications among cells in spheroids, spheroid secreted exosomes which account for transcellular transportation should exceed those from 2D cell culture and may display a different expression pattern of miRNA or protein. To test this, we employed a widely used pancreatic cancer cell line, PANC-1, to create 3D spheroids and compared exosomes generated by both 2D cell culture and 3D PANC-1 spheroids. We further measured and compared exosomal miRNA and GPC-1 protein expression with qRT-PCR and enzyme-linked immunosorbent assay, respectively. It showed that PANC-1 cells cultured in 3D spheroids can produce significantly more exosomes than PANC-1 2D cells and exosomal miRNA and GPC-1 expression derived from spheroids show more features relevant to the progression of pancreatic cancer. These findings point to the potential importance of using spheroids as in vitro model to study cancer development and progression.

[Effects of Cd on rape growth and antioxidant enzyme system].

The study with pot experiment showed that the fresh weights of rape plant and leaf decreased with increasing Cd concentration, and the decrease of leaf fresh weight resulted in the decrease of whole plant fresh weight. The permeability of cell membrane and the content of MDA increased with increasing Cd concentration. When the concentration of Cd was 20 mg x kg(-1), compared with the control, cell membrane permeability and MDA content were increased by 29.68% and 15.19% respectively, and there was a significant correlation between these two indices. When the Cd concentration was 5 mg x kg(-1), the contents of chlorophyll a, b and a + b reached their peaks, and were 23.97%, 33.63% and 26.45% higher than the control, respectively. Cd stress had no significant effect on carotenoid content. The sensibility of the pigments to Cd stress was chlorophyll b> chlorophyll a> chlorophyll a + b> carotenoid, and that of protective enzymes was POD>CAT>SOD. The IC50 of test physiological indices suggested that rape could only grow well on the soil with < 5 mg x kg(-1) Cd.

[Effects of different concentration copper on pigment content and antioxidase system of Spirodela polyrrhiza and Lemna minor].

The study with water culture showed that when treated with 0.056 mg Cu x L(-1), the chlorophyll a, b and (a + b) contents in Spirodela polyrrhiza and Lemna minor were increased by 11%, 46% and 22%, and 8%, 15% and 11%, while under 0.15 to approximately 5.6 mg Cu x L(-1) the contents were decreased by 63%, 62% and 63%, and 46%, 45% and 45%, respectively, compared with no copper added. The malondialdehyde (MDA) content in S. polyrrhiza was 2.75 times higher than that in L. minor averagely. The superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities in both S. polyrrhiza and L. minor all increased first, but decreased then with increasing copper concentration. For S. polyrrhiza, the activities of test enzymes were the highest at 0.18 mg Cu-L(-1), but for L. minor, only when the Cu concentrations were up to 0.56, 1.0 and 1.0 mg x L(-1), the activities of SOD, CAT and POD got to their peak values, respectively. It was concluded that higher concentrations of copper caused more damage to S. polyrrhiza than to L. minor, and the antioxidase system of the former was much more sensitive to the copper stress than that of the latter.

[Cd, Cu, Zn and Pb contents and forms in soils and rapeseeds around Wuhu Plant].

The study showed that around Wuhu Plant, soil Cd, Zn and Pb mainly existed in Fe-Mn oxide form, and Cu in residual form, with the percentage of 31.81%, 39.83%, 53.79%, and 46.24%, respectively. Soil exchangeable Cd and Pb had a higher proportion (23.47% and 16.32%) than soil exchangeable Cu and Zn (3.14% and 0.54%). The correlations between soil heavy metals and their forms, as well as their transformation to available form were different. Different heavy metals had different accumulation trends in rapeseed and its hull. Cu easily accumulated in hull, while Cd, Zn and Pb had a higher accumulation in seed. The accumulation rate of heavy metals in rapeseed and hull was also different, being the highest for Cd. There was a significantly negative correlation (P < 0.05) between the accumulation rate of heavy metals and their contents in soil. In rapeseed, Cd, Cu and Pb were mainly in sodium hydroxide form, with the percentage of 32.50%, 22.94% and 34.69%, respectively, while Zn was mainly in EDTA form, with a percentage of 45.97. The existed forms of heavy metals in rapeseed probably affected their toxicity, but the toxicity to human food could not be inferred from this research, and needed to be studied further. There was a weak relation between heavy metals contents and their existed forms in rapeseed.