Interaction of Human Serum Album and C60 Aggregates in Solution

An important property of C60 in aquatic ecotoxicology is that it can form stable aggregates with nanoscale dimensions, namely nC60. Aggregation allows fullerenes to remain suspended for a long time, and the reactivity of individual C60 is substantially altered in this aggregate form. Herein, we investigated the interaction of nC60 and human serum album (HSA) using the methods of fluorescence, fluorescence dynamics, circular dichroism (CD), and site marker competitive experiments. We proposed a binding model consistent with the available experimental results for the interactions of nC60 with HSA. During the interaction process, the structure and conformation of HSA were affected, leading to functional changes of drug binding sites of HSA

Enhanced depolluting capabilities of microbial bioelectrochemical systems by synthetic biology

Microbial bioelectrochemical system (BES) is a promising sustainable technology for the electrical energy recovery and the treatment of recalcitrant and toxic pollutants. In microbial BESs, the conversion of harmful pollutants into harmless products can be catalyzed by microorganisms at the anode (Type I BES), chemical catalysts at the cathode (Type II BES) or microorganisms at the cathode (Type III BES). The application of synthetic biology in microbial BES can improve its pollutant removing capability. Synthetic biology techniques can promote EET kinetics, which is helpful for microbial anodic electro-respiration, expediting pollutant removing not only at the anode but also at the cathode. They offer tools to promote biofilm development on the electrode, enabling more microorganisms residing on the electrode for subsequent catalytic reactions, and to overexpress the pollutant removing-related genes directly in microorganisms, contributing to the pollutant decomposition. In this work, based on the summarized aspects mentioned above, we describe the major synthetic biology strategies in designing and improving the pollutant removing capabilities of microbial BES. Lastly, we discuss challenges and perspectives for future studies in the area

Graphene oxide enhances the specificity of the polymerase chain reaction by modifying primer-template matching

Abstract Aiming at improved specificity, nanoparticle assisted polymerase chain reaction (PCR) has been widely studied and shown to improve PCR. However, the reliability and mechanism of this method are still controversial. Here, we demonstrated that 1 μg/mL of graphene oxide (GO) effectively enhances the specificity of the error-prone multi-round PCR. Mismatched primers were designed as interference to produce nonspecific products when the same amounts of matched and mismatched primers were added into semi-multiplex PCR. It was found that GO can enhance specificity by suppressing the amplification of mismatched primers. We monitored the primer-template-polymerase-GO interactions involved in the PCR using a capillary electrophoresis/laser-induced fluorescence polarization (CE-LIFP) assay. The results showed that the addition of GO promoted the formation of a matched primer-template complex, but suppressed the formation of a mismatched primer-template complex during PCR, suggesting that interactions between the primers and GO play an essential role. Furthermore, we successfully amplified the FOXL2 gene from PEGFP-N1 vectors using GO to eliminate the nonspecific products in PCR. Taken together, these results suggest that the GO can be used as an efficient additive for improving the conventional PCR system

Entropy-driven three-dimensional DNA nanofireworks for simultaneous real-time imaging of telomerase and microRNA in living cells

Real-time monitoring of different types of intracellular tumor-related biomarkers is of key importance for the identification of tumor cells. However, it is hampered by the low abundance of biomarkers, inefficient free diffusion of reactants, and complex cytoplasmic milieu. Herein, we present a stable and general method for in situ imaging of microRNA-21 and telomerase utilizing simple highly integrated dual tetrahedral DNA nanostructures (TDNs) that can naturally enter cells, which could initiate to form the three-dimensional (3D) higher-order DNA superstructures (DNA nanofireworks, DNFs) through a reliable target-triggered entropy-driven strand displacement reaction in living cells for remarkable signal amplification. Importantly, the excellent biostability, biocompatibility, and sensitivity of this approach benefited from (i) the precise multidirectional arrangement of probes with a pure DNA structure and (ii) the local target concentration enhanced by the spatially confined microdomain inside the DNFs. This strategy provides a pivotal molecular toolbox for broad applications such as biomedical imaging and early precise cancer diagnosis

Arsenic and Heavy Metal Accumulation and Risk Assessment in Soils around Mining Areas: The Urad Houqi Area in Arid Northwest China as an Example

Mining activities make important contributions to economic growth, but they can also produce massive amounts of solid waste, such as tailings and metal accumulations. Taking the Urad Houqi mining area in Inner Mongolia as the study area, this study systematically assessed the contamination risk of arsenic and heavy metals in the soils of the study area and explored the contamination characteristics in a key polymetallic mining area. For the whole study area, based on the Nemerow comprehensive pollution method, almost half of the investigated sites were contaminated, and the most contaminated site was Urad Houqi Qianzhen Mineral Concentration Co., Ltd. (Bayannaoer, China), a cooperation between the lead and zinc mining industry. The assessment results indicated that Cd and As were the elements of greatest concern, followed by Pb, Cr and Hg. Particularly, for the typical Dongshengmiao mining area, when compared with the GB15618-1995 standard values, As, Zn and Cd posed the most serious contamination threat, while Cr and Ni exhibited clean conditions. In addition, the vertical distribution maps demonstrated that the contents of arsenic and metals in some soil profiles were correlated with sampling depth. Therefore, arsenic and heavy metals pose high threat to soil ecosystems in this area, there is encouragement for some control and remediation measures to be taken into effect

Evaluating estrogenic and anti-estrogenic effect of endocrine disrupting chemicals (EDCs) by zebrafish (Danio rerio) embryo-based vitellogenin 1 (vtgl) mRNA expression

By measuring the vitellogenin 1 (vtgl) expression through quantitative PCR and in situ hybridization, we used the zebrafish embryo as an in vivo model to access the estrogenic or anti-estrogenic effects of several endocrine disrupting chemicals (EDCs), such as natural estrogen 17 beta-estradiol (E2), estriol (E3), synthetic hormones including diethylstilbestrol (DES), 4-octyl phenol (OP), bisphenol A (BPA), tamoxifen (TMX) and 3-(2,3-dibromopropyl) isocyanurate (TBC). According to our data, the estrogenic effect Of the tested chemicals was ranked as: DES > E-2 > E-3 > OP > BPA, which is consistent with various in vivo and in vitro models. Therefore, the measurement of vtgl gene expression in zebrafish embryos would be a valuable method for screening EDCs including both environmental estrogens and anti-estrogens

Exposure to legacy and novel perfluoroalkyl substance disturbs the metabolic homeostasis in pregnant women and fetuses: A metabolome-wide association study

Background: Perfluoroalkyl substances (PFASs) exist extensively and several of these have been verified to be toxic. Prenatal exposure to PFASs has attracted much attention. Metabolome-wide association analyses can be used to explore the toxicity mechanisms of PFASs by identifying associated biomarkers. Objectives: To evaluate associations between the metabolites in maternal and cord serum and internal exposure to several common PFASs. Methods: Paired maternal and cord serum samples were collected from 84 pregnant women who gave birth between 2015 and 2016. Seven legacy and two novel PFASs were measured. A nontarget metabolomic method and an iterative metabolite annotation based on metabolic pathways were applied to characterize the metabolic profiles. Linear regression adjusted with the false discovery rate and covariates was used to indicate the associations. Results: A total of 279 features in maternal serum and 338 features in cord serum were identified as metabolites associated with PFAS exposure. Perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) were two PFASs associated with more metabolites, while the two novel chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs) showed less relevance to the metabolome. With pathway enrichment analysis, we found that three fatty acid metabolisms and retinol metabolism were correlated with PFAS exposure in maternal blood, and that sterol metabolism showed the correlation in both maternal serum and cord serum. Conclusions: We identified metabolites and pathways in pregnant women and fetuses associated with the exposure to several PFAS, indicating a promising application for metabolome-wide association studies. Additional research is needed to confirm causation