Layer-by-Layer Engineered Superparamagnetic Polyelectrolyte Hybrid Hollow Microspheres With High Magnetic Content as Drug Delivery System

<div><p>Polyelectrolyte hybrid hollow microspheres with sandwich structure of about 450 nm have been accomplished by layer-by-layer self-assembling of two modified ferroferric oxide nanoparticles, lysine modified ferroferric oxide nanoparticles (Fe₃O₄-LYs) and citrate modified ferroferric oxide nanoparticles (Fe₃O₄-CA), as the main assembling materials via electrostatic interaction for the first time. They are superparamagnetic with saturation magnetization of 45.69 emu/g, revealing their high magnetic content of 70%. As drug delivery system, they also exhibited pH-stimuli responsive controlled release of an anticancer drug doxorubicin, following the Fickian diffusion model. Their unique structure and high magnetic content make them good candidate for targeted delivery.</p></div

Effects of drought on transcript levels of six genes encoding ASA-GSH cycle enzymes in the flag leaves, glumes, and lemmas of wheat at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.

<p>Transcripts were analyzed by qRT-PCR using <i>Tubulin</i> gene as internal control. Each value is the mean ± standard deviation of three independent measurements. Values with different letters indicated the significant differences at <i>P < 0</i>.<i>05</i> level in each stress treatment through time according to Duncan’s multiple range test.</p

Photosynthetic and ascorbate-glutathione metabolism in the flag leaves as compared to spikes under drought stress of winter wheat (<i>Triticum aestivum</i> L.)

<div><p>Ascorbate-glutathione (ASA-GSH) cycle is a major pathway of H₂O₂ scavenging and an effective mechanism of detoxification in plants. The differences in photosynthesis, chlorophyll content (Chl), relative water content (RWC), antioxidants and antioxidative enzyme activities involved in ASA-GSH metabolism were measured between the flag leaves and spike bracts (glumes and lemmas) during grain filling under drought stress. The expression of <i>APX1</i>, <i>GRC1</i>, <i>DHAR</i>, <i>MDHAR</i>, <i>GPX1</i>, and <i>GS3</i> in ASA-GSH cycle was also measured. Compared with the flag leaves, the spike bracts exhibited stable net photosynthetic rate (<i>P</i>_<i>N</i>) and chlorophyll content (Chl), a lower accumulation of reactive oxygen species (ROS), and more enhanced percentages of antioxidant enzyme activities and key enzymes gene transcription levels involved in ASA-GSH metabolism during the grain-filling stage under drought conditions. This could be the reasonable explanation for the more stable photosynthetic capacity in spikes, and the glumes and lemmas senesced later than the flag leaves at the late grain-filling stage. Also, the function of ASA-GSH cycle could not be ignored in alleviating oxidative damage by scavenging more excess ROS in spikes under drought stress.</p></div

Effects of drought stress on the ratios of GSH/GSSG (A, B, and C) and ASA/DHA (D, E, and F) of the flag leaves, glumes, and lemmas at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.

<p>All data represent means ± standard deviations (SD) of three replicates. Values with different letters indicated the significant differences at <i>P < 0</i>.<i>05</i> level in each stress treatment through time according to Duncan’s multiple range test.</p

DNA sequences of PCR primers were used for QRT-PCR determination of ASA-GSH biosynthesis-related genes in wheat.

<p>DNA sequences of PCR primers were used for QRT-PCR determination of ASA-GSH biosynthesis-related genes in wheat.</p

Effect of water deficit on antioxidant enzymes (APX, GR, DHAR, MDHAR, and GPX) activities involved in ASA-GSH metabolism in the flag leaves, glumes, and lemmas of wheat at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.

<p>All data represent means ± standard deviations (SD) of three replicates. Values with different letters indicated the significant differences at <i>P < 0</i>.<i>05</i> level in each stress treatment through time according to Duncan’s multiple range test.</p

Chlorophyll content (Chl) and relative water content (RWC) of the flag leaves (A, D), glumes (B, E), and lemmas (C, F) at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.

<p>All data represent means ± standard deviations (SD) of three replicates. Values with different letters indicated the significant differences at <i>P < 0</i>.<i>05</i> level in each stress treatment through time according to Duncan’s multiple range test.</p

Malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents of the flag leaves, glumes, and lemmas at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.

<p>Malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents of the flag leaves, glumes, and lemmas at the grain-filling stage under well-watered (WW) and water-stressed (WS) conditions.</p

C–I···π Halogen Bonding Driven Supramolecular Helix of Bilateral <i>N</i>‑Amidothioureas Bearing β‑Turns

We report the first example of C–I···π halogen bonding driven supramolecular helix in highly dilute solution of micromolar concentration, using alanine based bilateral I-substituted <i>N</i>-amidothioureas that contain helical fragments, the β-turn structures. The halogen bonding interactions afford head-to-tail linkages that help to propagate the helicity of the helical fragments. In support of this action of the halogen bonding, chiral amplification was observed in the supramolecular helix formed in acetonitrile solution. The present finding provides alternative tools in the design of self-assembling macromolecules