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The emergence and spread of antibiotic-resistant Neisseria gonorrhoeae has led to difficulties in treating patients, and novel strategies to prevent and treat this infection are urgently needed. Here, we examined 21 different nanomaterials for their potential activity against N. gonorrhoeae (ATCC 49226). Silver nanoparticles (Ag NPs, 120 nm) showed the greatest potency for reducing N. gonorrhoeae colony formation (MIC: 12.5 µg/ml) and possessed the dominant influence on the antibacterial activity with their properties of the nanoparticles within a concentration range that did not induce cytotoxicity in human fibroblasts or epithelial cells. Electron microscopy revealed that the Ag NPs significantly reduced bacterial cell membrane integrity. Furthermore, the use of clinical isolates of multidrug-resistant N. gonorrhoeae showed that combined treatment with 120 nm Ag NPs and cefmetazole produced additive effects. This is the first report to screen the effectiveness of nanomaterials against N. gonorrhoeae, and our results indicate that 120 nm Ag NPs deliver low levels of toxicity to human epithelial cells and could be used as an adjuvant with antibiotic therapy, either for topical use or as a coating for biomaterials, to prevent or treat multidrug-resistant N. gonorrhoeae.

Programmable surface-patterned functional DNA density is achieved via manipulation of molecular-level defects through chemical lift-off lithography. Artificial SAM defects are well-tunable by a contact-induced reaction, enabling molecular environment guidance and DNA insertion to be spatially and quantitatively addressable. This straightforward molecular density control creates an advanced avenue toward fabricating multiplexed bioactive substrates.

Phthalates are considered endocrine disruptors. Our study assessed the gender-specific effects of phthalate exposure on thyroid function in children. In total, 189 Taiwanese children were enrolled in the study. One-spot urine and blood samples were collected for analyzing 12 phthalate metabolites in urine and thyroid hormones. The association between urinary phthalate metabolites and serum thyroid hormones was determined using a generalized linear model with a log link function; the children were categorized into groups for analysis according to the 33rd and 66th percentiles. The data were stratified according to gender and adjusted for a priori defined covariates. In girls, a positive association existed between urinary di-2-ethylhexyl phthalate (DEHP) metabolites (mono-(2-ethylhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-(2-ethyl-5-hydroxyhexyl) phthalate) and free thyroxine (T4). In boys, urinary dibutyl phthalate (DBP) metabolites (mono-i-butyl phthalate and mono-n-butyl phthalate) were positively associated with free triiodothyronine (T3). After categorizing each exposure into three groups, urinary DEHP metabolites were positively associated with free T3 levels in boys. Our results suggested that DEHP is associated with free T4 in girls and that DBP is associated with free T3 in boys. Higher DEHP metabolite concentrations exerted larger effects on free T3 in boys. These results reveal the gender-specific relationships between phthalate metabolites and thyroid hormones.

The classical alkanethiol post-passivation can prevent nonspecific binding of nucleotide bases onto supporting substrates and help aptamers transition from a "lying down" to a "standing up" orientation. However, the surface probes display lower binding affinity towards targets than those in bulk solutions due to unsatisfied hybridization spaces on the alkanethiol passivated substrate. To overcome this challenge, an artificial defect-rich matrix possessing an aptamer "self-standing" property created by chemical lift-off lithography (CLL) is demonstrated. This approach provided artificial defects on a hydroxyl-terminated alkanethiol self-assembled monolayer (SAM), which allowed the insertion of thiolated aptamers. The diluted surface molecular environment assisted aptamers not only to "self-stand" on the surface, but also to separate from each other, providing a suitable surface aptamer density and sufficient space for capturing targets. With this approach, the binding affinity of the aptamer towards a target was comparable to solution-type probes, showing higher recognition efficiency than that in conventional methods.

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