Synthesis and gelation property of amino acids-based dendronised oligomers

<div><p>The first- and second-generation dendrons constructed from alanine and aspartic acids were synthesised and further modified with a polymerisable acrylamide group at the focal point (MG1 and MG2). The corresponding dendronised oligomers were obtained by polymerisation, and then hydrolysed to afford them with multi-carboxyl groups on the periphery of branched side chains (PG1-COOH and PG2-COOH). The structures of the oligomers were characterised by ¹H NMR, Fourier transform infrared and gel permeation chromatograph, and their gelation behaviour was examined. It was found that PG1-COOH and PG2-COOH could form two-component gels, especially, PG1-COOH showed better gelation property. For example, it could gel with aliphatic primary or secondary amines in dimethylformamide and with melamine in acidic aqueous solution. Transmission electron microscopy and atomic force microscopy images showed that the gelators self-assembled into the fibrous networks.</p></div

Effects of <i>Helicoverpa armigera</i> HMGR (HaHMGR) RNA interference (RNAi) on the oviposition of <i>H.</i><i>armigera</i>.

<p>Twenty dsRNA-treated or nuclease-free water-treated females were mated with untreated males in cages (40 cm×30 cm×30 cm). The enhanced green fluorescent protein double-stranded RNA (dsEGFP) treatment group was used as a negative control. Nuclease-free water was used as a blank control. Histograms represent the average oviposition per female. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

Neighbor-joining phylogenetic tree of the amino acid sequences of HMGR by Molecular Evolutionary Genetics Analysis Software Version 4.0 (MEGA4).

<p>The branches were statistically evaluated by bootstrap analysis. All sequences were from GenBank.</p

RNAi Silencing of the HaHMG-CoA Reductase Gene Inhibits Oviposition in the <i>Helicoverpa armigera</i> Cotton Bollworm

<div><p>RNA interference (RNAi) has considerable promise for developing novel pest control techniques, especially because of the threat of the development of resistance against current strategies. For this purpose, the key is to select pest control genes with the greatest potential for developing effective pest control treatments. The present study demonstrated that the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase; HMGR) gene is a potential target for insect control using RNAi. HMGR is a key enzyme in the mevalonate pathway in insects. A complete cDNA encoding full length HMGR (encoding an 837-aa protein) was cloned from <i>Helicoverpa armigera</i> (Lepidoptera: Noctuidae). The HaHMGR (<i>H. armigera</i> HMGR) knockdown using systemic RNAi <i>in vivo</i> inhibited the fecundity of the females, effectively inhibited ovipostion, and significantly reduced vitellogenin (Vg) mRNA levels. Moreover, the oviposition rate of the female moths was reduced by 98% by silencing HaHMGR compared to the control groups. One-pair experiments showed that both the proportions of valid mating and fecundity were zero. Furthermore, the HaHMGR-silenced females failed to lay eggs (approximate 99% decrease in oviposition) in the semi-field cage performance. The present study demonstrated the potential implications for developing novel pest management strategies using HaHMGR RNAi in the control of <i>H. armigera</i> and other insect pests.</p></div

The relative expression of <i>Helicoverpa armigera</i> HMGR (HaHMGR) and vitellogenin in <i>H.</i><i>armigera</i> after injecting dsRNA.

<p>(A) Histograms represent the expression of HaHMGR after injecting HaHMGR double-stranded RNA (dsHaHMGR). (B) The expression of vitellogenin after injecting dsHaHMGR. The enhanced green fluorescent protein double-stranded RNA (dsEGFP) treatment group was used as a negative control, and nuclease-free water was used as a blank control. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

Reprogrammable, Reprocessible, and Self-Healable Liquid Crystal Elastomer with Exchangeable Disulfide Bonds

A liquid crystal elastomer (LCE) can be regarded as an integration of mesogenic molecules into a polymer network. The LCE can generate large mechanical actuation when subjected to various external stimuli. Recently, it has been extensively explored to make artificial muscle and multifunctional devices. However, in the commonly adopted two-step crosslinking method for synthesizing monodomain LCEs, the LCE needs to be well-cross-linked in the first step before stretching, which increases the disorder of mesogenic molecules in the final state of the LCE and makes it very challenging to fabricate the LCE of complex shapes. In this article, we developed a new LCE with disulfide bonds, which can be reprogrammed from the polydomain state to the monodomain state either through heating or UV illumination, owing to the rearrangement of the polymer network induced by the metathesis reaction of disulfide bonds. In addition, the newly developed LCE can be easily reprocessed and self-healed by heating. Because of the excellent reprogrammability as well as reprocessability of the LCE, we further fabricated LCE-based active micropillar arrays through robust imprint lithography, which can be hardly achieved using the LCE prepared previously. Finally, we showed an excellent long-term durability of the newly developed LCE

Effect of dsHaHMGR on fecundity, larval production and number of spermatophores in <i>Helicoverpa armigera</i>.

<p>Two-day-old female pupae were treated with 1 µg of HaHMGR double-stranded RNA (dsHaHMGR) or enhanced green fluorescent protein double-stranded RNA (dsEGFP) (negative control). One female treated with dsRNA (dsHaHMGR or dsEGFP) was paired with an untreated male in a small cage (N = 30). Values are expressed in absolute terms as a percentage or as the mean ± SD. Values with the same letter are not significantly different at the <i>P</i>>0.05 level (ANOVA followed by Tukey’s post-hoc test).</p

APN induces autophagy in macrophage through Akt-FOXO3a pathway.

<p>A, Western blot shows the protein level of p-Akt, Akt, p-FOXO3a, FOXO3a in macrophages stimulated with phosphate buffered saline, APN, Akt agonist (740Y-P) or with APN in combination with 740Y-P. B, Western blot shows the protein level of PTEN, p-mTOR, mTOR in macrophages stimulated with phosphate buffered saline, APN, Akt agonist (740Y-P) or with APN in combination with 740Y-P. C, Quantitative analysis of p-Akt/Akt ratio, p-FOXO3a/FOXO3a ratio and p-mTOR/mTOR ratio in macrophages stimulated with phosphate buffered saline, APN, and APN in combination with 740Y-P, respectively. n = 6 per group. *P<0.05 versus macrophage treated with saline. D, Quantification of the optical density of PTEN in each groups. n = 6 per group. *P<0.05 versus macrophage treated with saline.</p

APN exacerbates macrophage autophagy in vitro.

<p>A and B respectively show the representative western blot and quantitative analysis of LC3 protein level in VSMC and macrophage stimulated with or without APN (5 μg/ml). n = 6 per group. *P<0.05 versus macrophage without APN. C and D respectively show the western blot and quantitative analysis of P62 and Beclin 1 protein level in macrophage treated with or without APN (5 μg/ml). n = 6 per group. *P<0.05 versus macrophage without APN.</p

An Enzyme-Responsive Nanogel Carrier Based on PAMAM Dendrimers for Drug Delivery

G4 PAMAM dendrimer molecules were modified via covalently conjugating RGDC, RAADyC, and PEG chains on the periphery (<b>Mac-1</b>), by which a nanogel drug carrier with enzyme-sensitivity (<b>NG-1</b>) was constructed through an oxidation reaction by using NaIO₄ to initiate the chemical cross-link of the functional groups on the periphery of dendrimers. <b>Mac-1</b> and <b>NG-1</b> both had a spherelike shape with a relatively uniform size of 20 nm for <b>Mac-1</b> and 50 nm for <b>NG-1</b> as evidenced by TEM, SEM, and DLS measurements. <b>NG-1</b> showed much higher drug loading capacity as compared with that of <b>Mac-1</b> although the cavities in the dendritic structure were used to encapsulate drug molecules as reported in many literatures. In addition, the size of <b>NG-1</b> with embedded doxorubicin hydrochloride (DOX) decreased significantly to 15 nm in the presence of elastase, which indicated the decomposition of the nanogel triggered by enzyme, leading to drug release in a sustained manner <i>in vitro</i>. The <b>NG-1</b> carrier was noncytotoxic and biocompatible, and it achieved the same cytotoxicity as free DOX when the drug molecules were loaded inside. From confocal images, the penetrative process of DOX from nanogel could be clearly observed in 8 h. Such a dendrimer-based nanogel may be a potential nanocarrier for drug delivery in cancer therapy