Adsorption of DNA by using polydopamine modified magnetic nanoparticles based on solid-phase extraction.

A polydopamine magnetic composite (PDA@Fe3O4) was prepared for the extraction of human genomic DNA and characterized by transmission electron microscopy, X-ray diffraction, FT-IR spectrometer, zeta potential and vibrating sample magnetometry. PDA@Fe3O4 based on magnetic solid phase extraction (MSPE) method have highly efficient capture of genomic deoxyribonucleic acid (DNA)and gene fragments ranging from about 100 bp to 200 bp. Compared with commercial beads (Shenggong, China) and spin column nucleic acid extraction kit (Tiangen, China), the PDA coated magnetic nanoparticles display superior genomic DNA extraction capacity (116 mg/g) and yield (90.2%). The isolation protocol used the solutions (composed of PEG and NaCl) with a specific pH for the binding and release of DNA. The procedure can be attributed to the charge switch of amino and hydroxyl groups on surface of the magnetic particle. The extracted DNA with high quality (A260/A280 = 1.82 ±â€¯0.04) can be directly used as template for polymerase chain reaction (PCR) followed by agarose gel electrophoresis. The results showed the new composite to be an ideal adsorbent for separation of DNA which had the advantage of its low cost, high extraction capacity and yield.

Effect of leaves damaged by Dendrolimus punctatus and insect frass on soil priming effect.

Insect herbivory in the forest canopy leads to a large amount of damaged leaves and frass input to soil, with consequence on soil carbon cycle. However, the influence of damaged leaves and frass from insect canopy herbivory on the soil priming effect is unclear. We examined the effects of leaf litter, leaf damage caused by Dendrolimus punctatus, and insect frass on soil priming effect by using the 13C natural abundance technique. The results showed that the addition of leaf litter, damaged leaves, and frass significantly increased native soil organic carbon mineralization, producing a positive priming effect. Moreover, significant differences were observed among treatments. The accumulative priming effect induced by frass was the largest, followed by damaged leaves, and that of leaf litter was the smallest. The priming effect was positively correlated with total P, condensed tannin, total phenolic content, and the ratio of condensed tannin to P (condensed tannin/P), and negatively correlated with C/N, lignin/N, C/P, and lignin/P in the early stage of incubation. There was a significant negative correlation between the priming effect and lignin content in the later stage of incubation. Our results indicated that damaged leaves and frass increased the magnitude of positive priming effect, which was influenced by different factors at different incubation stages. Our results would strengthen the understanding in the effects of insect herbivory on soil carbon cycling in forests, and improve the accuracy of the assessment of its effects on forest carbon sink.

Disrupted microbiota-barrier-immune interaction in phthalates-mediated barrier defect in the duodenum.

As one of the most used phthalates, Di (2-ethylhexyl) phthalate (DEHP) is a widespread environmental contaminant. Extremely persistent plastic can enter the food chain of animals through the aquatic environment, affect metabolic pathways and cause damage to the digestive system. But the molecular mechanism of its toxic effects on the duodenum in birds has not been elucidated. To investigate the toxicity of phthalates in the duodenum, quails were gavaged with 250, 500, and 750 mg/kg doses of DEHP for 45 days, and water and oil control groups were retained. This study revealed that subchronic exposure to DEHP could lead to duodenal barrier defect in quail. The damage to duodenum was reflected in a reduction in V/C and tight junction proteins. Moreover, DEHP also led to a breakdown of antimicrobial defenses through the flora derangement, which acted as a biological barrier. The massive presence of Lipopolysaccharide (LPS) led to the activation of TLR4 receptors. In addition, DEHP activated oxidative stress, which synergized the inflammatory response induced by the TLR4-NFκB pathway, and further promoted duodenum damage. This study provides a base for the further effect of phthalates on the microbiota-barrier-immune interaction.

Multifunctional cotton non-woven fabrics coated with silver nanoparticles and polymers for antibacterial, superhydrophobic and high performance microwave shielding.

Multifunctional cotton fabrics have attracted significant attention as next-generation wearable materials. Herein, we report a facile method for the fabrication of flexible and wearable cotton fabrics with ultra-high electromagnetic interference (EMI) shielding, antibacterial, and superhydrophobic properties. Cotton fabrics were first coated chemically with silver nanoparticles using polydopamine as adhesive and then with hydrophobic polydimethylsiloxane or polyimide. The introduction of polydopamine significantly increased the bond between silver nanoparticles and cotton fibers, thereby preventing silver nanoparticles from falling off the surface. The composite fabrics exhibited a high conductivity of ~1000 S/cm, and their EMI shielding effectiveness increased up to ~110 dB. The composite fabrics exhibited excellent self-cleaning performance and acid-alkali corrosion resistance because of their superhydrophobicity. Notably, the fabric composites showed a significant antibacterial action against Staphylococcus aureus and Escherichia coli.

Efficient scald-preventing enabled by robust polyester fabrics with hot water repellency and water impalement resistance.

Scald is a kind of common injury for human beings caused by contacting with hot liquids and/or vapor. Herein, we report the preparation of an advanced fabric for efficient scald-preventing by dip-coating a common polyester fabric in a hexadecyl polysiloxane (HD-POS) aqueous suspension, which was synthesized via a waterborne and nonfluorinated approach. Thanks to the hierarchical micro-/nanostructure of the fabric, stable bonding of the compact HD-POS layer on the polyester microfibers, and inherent high stability and elasticity of HD-POS, the fabric features excellent hot water repellency even for dynamic boiling water with a high water impalement resistance of up to 5 grades according to the water repellency grade test. In addition, the fabric shows extraordinary mechanical stability, e.g., its superhydrophobicity remained nearly unchanged after 200 cycles washing, 10,000 cycles Martindale abraison or 1000 cycles 100% streching and releasing. It also exhibits superior environmental robustness (117 d outdoor test) and chemical robustness (7 d immersion in 1 M HCl or NaOH solution, 60 min ultrosonication in both water and anchol immersion) in various harsh conditions. By applying as an advanced fabric for efficient scald-preventing, it can avoid direct contact of hot water and vapor with rat skin by preventing penetration of hot water and most of vapor. It could also significantly reduce heat conduction and radiation to rat skin by reducing contact time of hot water with the fabric (decreased 10 s more quickly than the pristine fabric to 60 °C when encountering 100 mL of 92 °C water). As a result, the fabric in contact with the skin keeps dry and the fabric temperature is much lower than that of the pristine fabric once encountering hot water, thus showing great potentials as an advanced fabric for efficient scald-preventing applications.

Magnetic resonance imaging of osteosarcoma using a bis(alendronate)-based bone-targeted contrast agent.

Magnetic resonance (MR) is currently used for diagnosis of osteosarcoma but not well even though contrast agents are administered. Here, we report a novel bone-targeted MR imaging contrast agent, Gd2-diethylenetriaminepentaacetate-bis(alendronate) (Gd2-DTPA-BA) for the diagnosis of osteosarcoma. It is the conjugate of a bone cell-seeking molecule (i.e., alendronate) and an MR imaging contrast agent (i.e., Gd-DTPA). Its physicochemical parameters were measured, including pKa, complex constant, and T1 relaxivity. Its bone cell-seeking ability was evaluated by measuring its adsorption on hydroxyapatite. Hemolysis was investigated. MR imaging and biodistribution of Gd2-DTPA-BA and Gd-DTPA were studied on healthy and osteosarcoma-bearing nude mice. Gd2-DTPA-BA showed high adsorption on hydroxyapatite, the high MR relaxivity (r1) of 7.613mM-1s-1 (2.6 folds of Gd-DTPA), and no hemolysis. The MR contrast effect of Gd2-DTPA-BA was much higher than that of Gd-DTPA after intravenous injection to the mice. More importantly, the MR imaging of osteosarcoma was significantly improved by Gd2-DTPA-BA. The signal intensity of Gd2-DTPA-BA reached 120.3% at 50min, equal to three folds of Gd-DTPA. The bone targeting index (bone/blood) of Gd2-DTPA-BA in the osteosarcoma-bearing mice was very high to 130 at 180min. Furthermore, the contrast enhancement could also be found in the lung due to metastasis of osteosarcoma. Gd2-DTPA-BA plays a promising role in the diagnoses of osteosacomas, including the primary bone tumors and metastases.

Improving oral bioavailability of metformin hydrochloride using water-in-oil microemulsions and analysis of phase behavior after dilution.

Microemulsions show significant promise for enhancing the oral bioavailability of biopharmaceutics classification system (BCS) class II drugs, but how about class III drugs remains unclear. Here we employed metformin hydrochloride (MET) as the model drug and prepared drug-loaded water-in-oil (W/O) microemulsions selecting different hydrophile-lipophile balance (HLB) surfactant systems, using HLB 8 as a cut-off. We examined the phase behaviors of microemulsions after dilution and attempted to correlate these behaviors to drug oral bioavailability. ME-A, including a lower content of surfactants (35%), underwent a transition of W/O emulsion and then became a stable O/W emulsion in a light milky appearance; ME-B, in contrast, introducing a higher content of surfactants (45%), still remained transparent or semitransparent upon dilution. Unexpectedly, ME-A showed significantly higher oral bioavailability, which can be reduced by blocking the lymphatic absorption pathway. Comparatively, the AUC of ME-B is lower, close to MET solution. Both microemulsions behaved similarly in intestinal perfusion test because of the dilution before perfusion, lacking of the important phase transition of W/O emulsion. These findings suggest that W/O microemulsions improve oral bioavailability of BCS class III drug by promoting lymphatic absorption. Analyzing the phase behavior of microemulsions after dilution may help predict the drug oral bioavailability and optimize formulations.