Here,
we constructed a nanostructured pH/redox dual-responsive
supramolecular drug carrier with both aggregation-induced emission
(AIE) and Forster resonance energy transfer (FRET) effects, which
enabled selective drug release and monitoring drug delivery and release
processes. Taking the hyperbranched polyamide amine (H-PAMAM) with
intrinsic AIE effects as the core, poly(ethylene glycol) (PEG) was
bridged on its periphery by dithiodipropionic acid. Then, through
the host–guest interaction of PEG and α-cyclodextrin,
the supramolecular nanoparticles with AIE effects were constructed
to load the anticancer drug doxorubicin (DOX). The supramolecular
assembly has sufficiently large DOX loading due to the abundant cavities
formed by branched structures. The hyperbranched core H-PAMAM has
strong fluorescence, and the dynamic track of drug carriers and the
dynamic drug release process can be monitored by the AIE and FRET
effects between H-PAMAM and DOX, respectively. Furthermore, the introduction
of disulfide bonds and the pH sensitivity of H-PAMAM enable the achievement
of rapid selective release of loaded DOX at the tumor while remaining
stable under normal physiological conditions. In vitro cytotoxicity
indicates that the drug-loaded supramolecular assembly has a good
therapeutic effect on cancer. In addition, the H-PAMAM core is different
from the traditional AIE functional group, which has no conjugated
structure, such as a benzene ring, thereby providing better biocompatibility.
This technology will have broad applications as a new drug delivery
system.
A rapid and sensitive detection platform for GSH has been constructed by combining a MnO nanosheet with a luminescent iridium(iii) complex [Ir(Cl-phq)(Cl-phen)]. The MnO nanosheet was prepared by using a facile one-step approach and was characterized by TEM. The luminescence intensity of the detection platform responded linearly with the GSH concentration from 1 to 200 μM (R = 0.9951), and the detection limit for GSH was 0.13 μM. More importantly, practical application of the detection platform for visualizing the intracellular GSH distribution in living zebrafish has also been demonstrated.
Key message
This study validated one QTL for adult plant resistance to stripe rust, identified donor lines of the resistance allele, and demonstrated that it is different from previously named
Yr
genes.
AbstractThe spread of more virulent and aggressive races of Puccinia striiformis f. sp. tritici (Pst, causal pathogen of stripe rust) after the year 2000 has caused substantial yield losses worldwide. To find new sources of resistance, we previously performed a genome-wide association study and identified a strong QTL for adult plant resistance on the short arm of chromosome 6B (QYr.ucw-6B). In this study, we validated QYr.ucw-6B in ten biparental populations, and mapped it 0.6 cM proximal to IWA7257 and 3.9 cM distal to IWA4408. We showed that QYr.ucw-6B is located approximately 15 cM proximal to the all-stage resistance gene Yr35 and that none of the resistant lines carries the previously cloned Yr36 gene. Based on these results, QYr.ucw-6B was assigned the name Yr78. This gene was not effective against Pst at the seedling stage, suggesting that it is an adult plant resistance gene. Yr78 has been effective against Pst races present in field experiments performed in the Western USA between 2011 and 2016. Since this gene is predicted to be present at low frequency in wheat germplasm from this region, it can provide a useful tool to diversify the sources of resistance against this devastating pathogen.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-017-2946-9) contains supplementary material, which is available to authorized users.
Facing the global
health crisis caused by drug-resistant bacteria, antimicrobial peptides
and their analogues offer exciting solutions to this widespread problem.
Without additionally introducing a fluorescent probe, novel nanoengineered
peptide-grafted hyperbranched polymers (NPGHPs) are constructed for
their combined outstanding antimicrobial activity and sensitive bacterial
detection in real time. Hyperbranched polyamide amine (H-PAMAM) that
exhibits aggregation-induced emission (AIE) effects is synthesized.
Then, NPGHPs are prepared by ring-opening polymerization of α-amino
acid N-carboxyanhydrides on the periphery of the
H-PAMAM. The NPGHPs exhibit high-efficiency antibacterial properties
against a wide spectrum of bacteria, especially against Gram-negative
bacteria. On the basis of the AIE effect of NPGHPs, the interaction
between NPGHPs and Escherichia coli is explored and the fluorescence intensity of NPGHPs is dependent
on the number of E. coli present. Thus,
a method for monitoring E. coli concentration
is developed, and the detection limit is 1 × 104 CFU
mL–1. Furthermore, NPGHPs are used as fluorescent
probes to visualize antibacterial process via lighting-up bacteria.
NPGHPs can penetrate the membrane of bacteria and cause cell rupture
and apoptosis. In addition, the excellent selectivity of NPGHPs toward
bacteria over mammalian cells makes them bright prospects for clinical
applications.
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