Characterization of 1,4-dioxane degrading microbial community enriched from uncontaminated soil.

1,4-Dioxane is a contaminant of emerging concern that has been commonly detected in groundwater. In this study, a stable and robust 1,4-dioxane degrading enrichment culture was obtained from uncontaminated soil. The enrichment was capable to metabolically degrade 1,4-dioxane at both high (100 mg L-1) and environmentally relevant concentrations (300 µg L-1), with a maximum specific 1,4-dioxane degradation rate (qmax) of 0.044 ± 0.001 mg dioxane h-1 mg protein-1, and 1,4-dioxane half-velocity constant (Ks) of 25 ± 1.6 mg L-1. The microbial community structure analysis suggested Pseudonocardia species, which utilize the dioxane monooxygenase for metabolic 1,4-dioxane biodegradation, were the main functional species for 1,4-dioxane degradation. The enrichment culture can adapt to both acidic (pH 5.5) and alkaline (pH 8) conditions and can recover degradation from low temperature (10°C) and anoxic (DO < 0.5 mg L-1) conditions. 1,4-Dioxane degradation of the enrichment culture was reversibly inhibited by TCE with concentrations higher than 5 mg L-1 and was completely inhibited by the presence of 1,1-DCE as low as 1 mg L-1. Collectively, these results demonstrated indigenous stable and robust 1,4-dioxane degrading enrichment culture can be obtained from uncontaminated sources and can be a potential candidate for 1,4-dioxane bioaugmentation at environmentally relevant conditions. KEY POINTS: •1,4-Dioxane degrading enrichment was obtained from uncontaminated soil. • The enrichment culture could degrade 1,4-dioxane to below 10 µg L-1. •Low Ks and low cell yield of the enrichment benefit its application in bioremediation.

Hybrid Poly(AMPS-CS)-Au Microneedle Arrays to Enrich Metabolites from Skin for Early Disease Diagnosis.

Recently, some metabolites in skin interstitial fluid (SIF) have become emerging re×sources for early disease diagnosis. However, their low level in SIF and difficulty to sampling are the biggest obstacle to further potential application. Here, a swellable microneedle array patch (MNAP) with high mechanical strength is presented, and the rapid enrichment of positively charged metabolites is achieved. The MNAP is fabricated by poly (chondroitin sulfate-acrylamido-2-methylpropane sulfonic acid)-gold nanoparticles (GNPs) composites via a micro-molding. The negatively charged copolymer hydrogel not only enrich positively charged metabolites, but also provide swellable capacity. The in situ synthesis of GNPs in the process of copolymerization make the GNPs cross-link to the hydrogel, which further enhance the MNAP mechanical strength and enrichment efficiency for positively charged metabolites. By using the MNAP, around 5 mg SIF in 10 min from the high fat/cholecalciferol/methimazole-induced atherogenesis rat is extracted and 23 metabolites including 13 quaternary ammonium cationic compounds can be detected and quantified by using a LC-QTOF-MS. Dysregulated L-carnitine and choline metabolism are discovered a week earlier in the SIF than in the serum, achieving early diagnosis of the metabolism syndrome disease. This MNAP also helps users complete home sampling for early disease diagnosis and monitoring.

Dendritic cells reprogrammed by CEA messenger RNA loaded multi-functional silica nanospheres for imaging-guided cancer immunotherapy.

The application and understanding of dendritic cell (DC) based immune cancer therapy are largely hindered by insufficient or improper presentation of antigens and the inability to track the homing of reprogrammed DCs to draining lymph nodes in real-time. To tackle these challenges, multi-functional and hierarchically structured silica nanospheres are rationally designed and fabricated, which encapsulate quantum dots to permit near infrared deep tissue imaging and are loaded with carcinoembryonic antigen messenger RNA (CEAmRNA) to enable stable and abundant antigen expression in DCs. After being injected into animals and inducing an antigen-specific immune response, the homing process of reprogrammed labelled DCs from peripheral tissues to draining lymph nodes can be simultaneously and precisely tracked. Significant inhibition of tumor growth is achieved via strong antigen-specific immune responses including induced DC maturation, enhanced T cell proliferation and cytotoxic T lymphocyte (CTL)-mediated responses. Both in vitro and in vivo experiments demonstrate the high effectiveness of this new strategy of imaging-guided cancer immunotherapy by using reprogrammed DCs as immunotherapeutic and tracking agents.