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Modifications of genomic DNA may change gene expression and cause adverse health effects. Here we for the first time demonstrate a particle counting immunoassay for rapid and sensitive detection of DNA modifications using benzo[a]pyrenediol epoxide (BPDE)--DNA adducts as an example. The BPDE-adducted DNA is specifically captured by immunomagnetic particles and then isolated from unmodified DNA by applying an external magnetic field. By taking advantage of the fluorescence signal amplification through multiple labeling of captured DNA by OliGreen dye, the captured BPDE--DNA adducts can be quantified by particle counting from fluorescence imaging. This clearly demonstrates that the number of fluorescently countable particles is proportional to the modification content in genomic DNA. It is interesting to note that the background fluorescence signal caused by nonspecific adsorption of OliGreen dye can be more effectively quenched than that induced by the binding of OliGreen dye to ssDNA, allowing for significant reduction in the background fluorescence and further enhancing the detection sensitivity. The developed method can detect trace BPDE--DNA adducts as low as 180 fM in the presence of I billion times more normal nucleotides in genomic DNA and has a dynamic range over 4 orders of magnitude. By using anti-5-methylcytosine antibody, the method is extended to the detection of global DNA methytation. With high sensitivity and specificity, this rapid and easy-to-perform analytical method for DNA modifications shows a broad spectrum of potential applications in genotexical and epigenetic analysis. 10.1021/ac102416f

Monitoring of over-expressed nucleolin in the cytoplasm facilitates early cancer diagnosis. Herein, we present a novel biosensing nanoscaffold based on anti-nucleolin aptamers and polymer-grafted graphene oxides for the fluorescent imaging of nucleolin in the cell cytoplasm, which can distinguish cancer cells from normal cells. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) has been extensively explored as a promising nanomaterial for applications in biology because of its unique properties. Therefore, systematic investigation of GO toxicity is essential to determine its fate in the environment and potential adverse effects. In this study, acute toxicity, oxidative stress and immunotoxicity of GO were investigated in zebrafish. No obvious acute toxicity was observed when zebrafish were exposed to 1, 5, 10 or 50 mg/L GO for 14 days. However, a number of cellular alterations were detected by histological analysis of the liver and intestine, including vacuolation, loose arrangement of cells, histolysis and disintegration of cell boundaries. As evidence for oxidative stress, malondialdehyde levels and superoxide dismutase and catalase activities were increased and glutathione content was decreased in the liver after treatment with GO. GO treatment induced an immune response in zebrafish, as demonstrated by increased expression of tumor necrosis factor α, interleukin-1 β, and interleukin-6 in the spleen. Our findings demonstrated that GO administration in an aquatic system can cause oxidative stress and immune toxicity in adult zebrafish. To our knowledge, this is the first report of immune toxicity of GO in zebrafish. [ABSTRACT FROM AUTHOR]

Exogenous and endogenous genotoxic carcinogens and their in vivo metabolites may result in DNA damage and cause adverse health effects. It is very difficult to specifically detect trace DNA damage in the presence of a large excess of unmodified nucleosides. Here we report a molecularly imprinted polymer (MIP) nanocomposite, namely nanoMIP, which can be used as a “plastic antibody” for specific recognition of benzo[a]pyrene diol epoxide (BPDE)–DNA adduct. Enhanced binding affinity (880 nM) of nanoMIPs was achieved by using two tailor-made functional monomers. The property of binding kinetics was greatly improved in virtue of the well-defined nanostructure, which was fabricated by initiators for continuous activator regeneration-atom transfer radical polymerization (ICAR-ATRP). The BPDE-adducted DNA can be specifically captured by synthetic nanoMIP. By taking advantage of this antibody-mimicking behavior, we further developed a fluorescently imaged particle counting immunoassay (FIPCIA) method for ultrasensitive detection of BPDE–ssDNA adducts using a laser scanning confocal microscope (LSCM). The number of countable fluorescent dots is proportional to the content of BPDE–ssDNA adducts in the DNA sample. The proposed plastic antibody-based FIPCIA method can detect traces of BPDE–DNA adducts as low as 18 pM in human lung carcinoma A549 cells. This highly-sensitive detection of DNA lesions offers a promising alternative to immunogenic antibody-based immunoassays for genomics and DNA modification analysis. [ABSTRACT FROM AUTHOR]

Abstract: A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was applied for simultaneous determination of stachyose, sucrose and raffinose in Chinese artichoke (Stachys Sieboldii Miq.). Carbohydrates were separated on a Bondapak NH2 column using a ternary solvent mixture of methanol–acetonitrile–water (55:25:20, v/v/v) as mobile phase. Two different crafts (method 1 and method 2) for extraction and purification of stachyose in Chinese artichoke tubers were detailed and evaluated. Method 1 can meet the purpose of quantification and method 2 is appropriate for the purpose of purification. The content of stachyose in dry tubers was determined to be 236.0mg/g (from method 1) and the purity of the extracted stachyose flour was calculated to be 87.34% (from method 2), respectively. The analytical method fulfills all the standard requirements of linearity, accuracy and precision. Therefore, it is suitable for purification and routine quantification of stachyose in Chinese artichoke. [Copyright &y& Elsevier]

Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release are fabricated by the combination of template synthesis and ATRP grafting. The release of R-propranolol from the imprinted nanotubes in rats is restricted while the release of pharmacologically active S-enantiomer is greatly promoted. [ABSTRACT FROM AUTHOR]

Long-term exposures to environmental toxicants are causative factors for human health effects. DNA damages are of great interest in that they can serve as the potential biomarkers of environmental exposure and mutations. Qualitative and quantitative detection of their level in genomic DNA, are helpful for the understanding of the generation, transformation, repair and fate of DNA damages and for elucidating the mechanism underlying carcinogenesis. Methodologies based on liquid chromatography-mass spectrometry (LC-MS) have shown unique advantages in accurate and highly sensitive analysis of these structurally modified DNA damages. The present review summarizes our current knowledge on LC-MS analysis of genetic DNA damages, with special emphasis on structurally chemical DNA modifications induced by environmental exposure. Advances in LC-MS analysis and monitoring of oxidative DNA lesion, DNA adducts induced by heavy metals, persistent organic pollutants, bisphenols, fine particulate matters, aldehydes and halobenzoquinones are comprehensively summarized. • Highly sensitive LC-MS methods for DNA damages analysis. • Oxidative DNA damages, DNA adducts induced by environmental exposure. • DNA modifications caused by new emerging contaminants including PM2.5 and BPA. • Advances in DNA damage monitoring and adductomics benefited from LC-MS/MS. [ABSTRACT FROM AUTHOR]

Abstract Four DNA bases are essential biochemical elements for coding heritable life blueprint. Meanwhile, organisms utilize modifying enzymes to post chemical groups on DNA bases to regulate gene expression, chromosome structures, and transposase activity, and to defense pathogens. The researches on the biochemical modifications of DNA bases are at the cutting edge of life sciences and chemical biology. Up to date, along with fantastic progresses, liquid chromatography hyphenated with mass spectrometry (LC-MS)-based technologies become popular and powerful tools for chemical structure-dependent identification and quantification of diverse DNA modifications. Here we provided comprehensive review on LC-MS-based technologies and related pretreatment technologies for profiling of epigenetic DNA modifications, mainly focusing on innovative technologies developed for desalting, DNA digestion, and ionization for mass spectrometry detection. We also summarized the epigenetic progresses, which benefited from the development of the LC-MS methodologies and technologies, on the studies of specific DNA modifications, in particular, 5-hydroxymethylcytosine and 5-formylcytosine. Highlights • LC-MS/MS methods for detection of epigenetic DNA modifications. • DNA hydrolysis for generation of LC-MS detectable mononucleosides. • Chemical approaches for enhancing LC-MS signal. • Progresses on epigenetic DNA modifications benefited from LC-MS/MS analysis. [ABSTRACT FROM AUTHOR]

8-Hydroxydeoxyguanosine (8-OHdG) is a widely-used biomarker of oxidative DNA damages. 8-OHdG in peripheral blood leukocyte is associated with mutation and cancer risk. The level of 8-OHdG in peripheral blood leukocytes can indicate a long-term response to oxidative stress rather than that in urine. Accurate identification and quantification of leukocyte 8-OHdG are essential for understanding its mechanism of formation, repair, and biological consequences. In this study, a fast and accurate ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC–MS/MS) method was developed and validated to detect 8-OHdG in human peripheral leukocyte. DNA in blood samples were extracted and digested, then subjected onto UHPLC–MS/MS using an isocratic elution on a Zorbax Eclipse Plus C18 column (2.1 × 100 mm, 1.8 μm). Multiple reaction monitoring (MRM) mode was adopted by using [ 15 N 5 ]-8-OHdG as an internal standard. The assay was linear over the concentration range of 1.0–100 nM with R 2 = 0.999. The accuracy for spiked samples was 90.9%–94.8%, and the intra-day precision was within 3.7%. The limit of detection (LOD) is 0.30 nM and limit of quantification (LOQ) is 1.0 nM with 5 μl of sample injection. By the analysis of human leukocyte 8-OHdG (n = 121) using the developed UHPLC–MS/MS method, it demonstrates that the level of leukocyte 8-OHdG of the cancer patients group (n = 46) is significantly higher than that of the health control (n = 75). [ABSTRACT FROM AUTHOR]

• A new molecular imprinting graphene nanocomposite (PIL-MIP/GO) was synthesized. • PIL-MIP/GO has fast mass transfer, rich adsorption mechanism, and high selectivity. • A HPLC-UV method for β-agonists was designed based on PIL-MIP/GO as PT-SPE sorbent. • The method was successfully applied to detect β-agonist in swine urine. • The analytical method was sensitive, selective, accurate, nonfatal, and economical. The illegal use of β-agonists often endangers animal-derived food safety. In this study, a selective detection method for β-agonists in swine urine was established via the combination of polymeric ionic liquid-molecularly imprinted graphene oxide-miniaturized pipette tip solid-phase extraction and high-performance liquid chromatography. It is worth noting that this method relied mainly on the designed adsorbent, which presented a rich adsorption mechanism, fast mass transfer rate, and high selectivity, and was successfully utilized in the selective extraction of β-agonists from swine urine samples. The proposed method has low LOD (0.20–0.56 ng/mL), high recovery (94.9–107.9%), and high reusability (4 times, 91.9–108.8%), which indicates its high potential as a selective, sensitive, accurate, and nonfatal method for monitoring the illegal use of β-agonists in the livestock breeding stage. [ABSTRACT FROM AUTHOR]

Highlights: [•] Different functionalized chemical groups affect the dispersibility of f-SWCNTs. [•] Insignificant effects on mitochondrial activity and ROS production in MCF7 cells by f-SWCNTs. [•] Exposure induced cell membrane damage and cell apoptosis, decreased cell adhesion. [Copyright &y& Elsevier]