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Synthetic multichromophore systems are of great importance in artificial light harvesting devices, organic optoelectronics, tumor imaging and therapy. Here, we introduce a promising strategy for the construction of self-assembled peptide templated dye stacks based on coupling of a de novo designed pH sensitive peptide with a cyanine dye Cy5 at its N-terminus. Microscopic techniques, in particular cryogenic TEM (cryo-TEM) and cryo-electron tomography technique (cryo-ET), reveal two types of highly ordered three-dimensional assembly structures on the micrometer scale. Unbranched compact layered rods are observed at pH 7.4 and two-dimensional membrane-like assemblies at pH 3.4, both species displaying spectral features of H-aggregates. Molecular dynamics simulations reveal that the coupling of Cy5 moieties promotes the formation of both ultrastructures, whereas the protonation states of acidic and basic amino acid side chains dictates their ultimate three-dimensional organization.

A new series of nonionic gemini amphiphiles have been synthesized in a multi-step chemoenzymatic approach by using a novel A2 B2 -type central core consisting of conjugating glycerol and propargyl bromide on 5-hydroxy isophthalic acid. A pair of hydrophilic monomethoxy poly(ethylene glycol) (mPEG) and hydrophobic linear alkyl chains (C12 /C15 ) were then added to the core to obtain amphiphilic architectures. The aggregation tendency in aqueous media was studied by dynamic light scattering, fluorescence spectroscopy and cryogenic transmission electron microscopy. The nanotransport potential of the amphiphiles was studied for model hydrophobic guests, that is, the dye Nile Red and the drug Nimodipine by using UV/Vis and fluorescence spectroscopy. Evaluation of the viability of amphiphile-treated A549 cells showed them to be well tolerated up to the concentrations studied. Being ester based, these amphiphiles exhibit stimuli-responsive sensitivity towards esterases, and a rupture of amphiphilic architecture was observed in the presence of immobilized Candida antarctica lipase (Novozym 435), thus facilitating release of the encapsulated guest from the aggregate.

Pneumolysin (PLY) is a pore-forming, cholesterol-dependent cytolysin (CDC) from Streptococcus pneumoniae, the main bacterial cause for community-acquired pneumonia. Liberation of PLY during host infection leads to strong immune activation and cytolytic cell death. Thus, inhibition of PLY could be a valuable approach to attenuate detrimental effects of hyper-inflammatory immune reactions during pneumococcal lung infection. Here, we report discovery, development, and validation of small molecule inhibitors of PLY, denominated as pore-blockers (PB). PB-1 was identified by combined screening inhibiting PLY-mediated hemolysis. PB-2 blocked pore formation with greatly improved potency as demonstrated by cryo-electron tomography. Scaffold-hopping delivered PB-3 with superior chemical stability, solubility, and a specific mode of action, characterized by an elongated residence time. It prevented human lung epithelial cells from PLY-mediated cytolysis and cell death, also during infection with Streptococcus pneumoniae. In conclusion, druglike PLY-inhibitors such as PB-3 might become valuable adjuvant options in the treatment of severe pneumococcal infections.

Divergence of chemical plant defence mechanisms within the Brassicaceae can be utilized to identify means against specialized pest insects. Using a bioassay-driven approach, we (a) screened 24 different Brassica napus cultivars, B. napus resyntheses and related brassicaceous species for natural plant resistance against feeding adults of the pollen beetle (Brassicogethes aeneus), (b) tested for gender-specific feeding resistance, (c) analysed the flower bud metabolomes by a non-targeted approach and (d) tested single candidate compounds for their antifeedant activity. (a) In no-choice assays, beetles were allowed to feed on intact plants. Reduced feeding activity was mainly observed on Sinapis alba and Barbarea vulgaris but not on B. napus cultivars. (b) Males fed less and discriminated more in feeding than females. (c) Correlation of the metabolite abundances with the beetles' feeding activity revealed several glucosinolates, phenylpropanoids, flavonoids and saponins as potential antifeedants. (d) These were tested in dual-bud-choice assays developed for medium-throughput compound screening. Application of standard compounds on single oilseed rape flower buds revealed highly deterrent effects of glucobarbarin, oleanolic acid and hederagenin. These results help to understand chemical plant defence in the Brassicaceae and are of key importance for further breeding strategies for insect-resistant oilseed rape cultivars.

Flexible multivalent 3D nanosystems that can deform and adapt onto the virus surface via specific ligand–receptor multivalent interactions can efficiently block virus adhesion onto the cell. We here report on the synthesis of a 250 nm sized flexible sialylated nanogel that adapts onto the influenza A virus (IAV) surface via multivalent binding of its sialic acid (SA) residues with hemagglutinin spike proteins on the virus surface. We could demonstrate that the high flexibility of sialylated nanogel improves IAV inhibition by 400 times as compared to a rigid sialylated nanogel in the hemagglutination inhibition assay. The flexible sialylated nanogel efficiently inhibits the influenza A/X31 (H3N2) infection with IC50 values in low picomolar concentrations and also blocks the virus entry into MDCK‐II cells., Fighting influenza: Through the combination of flexibility and multivalent binding, a sialylated nanogel is able to bind and adapt onto the influenza A virus surface. The resulting flexible nanogel efficiently blocks the virus binding onto the cell and inhibits infection at low pm concentrations.

A series of six novel disulfide-bond-linked Gemini amphiphiles have been synthesized using polyethylene glycol (PEG) as hydrophilic units and alkoxy aryl moieties as hydrophobic units. The self-assembling behaviour of the resulting amphiphiles was studied using fluorescence spectroscopy and dynamic light scattering (DLS). The inner hydrophobic core with an alkyl and fluoroalkyl chain aggregates differently in aqueous medium as evidenced by a cryo-TEM study. Also they are found to be capable of encapsulating a lipophilic guest. The encapsulation behaviour was studied using Nile red as a model hydrophobic dye and extended further by including curcumin and an anti-cancerous drug doxorubicin. Furthermore, for biological evaluation, their cytotoxicity and cellular uptake were studied. The presence of stimuli responsive disulfide linkages and the ester functionality provides the possibility of redox responsive and enzymatic release of the encapsulated cargo, which was studied by using various concentrations of glutathione (GSH) and an immobilized lipase Novozym 435.

The introduction of stereogenic centers in supramolecular building blocks is used to unveil subtle changes in supramolecular structure and dynamics over time. Three stereogenic centers based on deuterium atoms were introduced in the side chains of a benzene-1,3,5-tricarboxamide (BTA) resulting in a supramolecular polymer in water that at first glance has a structure and dynamics identical to its achiral counterpart. Using three different techniques, the properties of the double helical polymers are compared after 1 day and 4 weeks. An increase in helical preference is observed over time as well as a decrease in the helical pitch and monomer exchange dynamics. It is proposed that the polymer of the chiral monomer needs time to arrive at its maximal preference in helical bias. These results indicate that the order and tight packing increase over time, while the dynamics of this supramolecular polymer decrease over time, an effect that is typically overlooked but unveiled by the isotopic chirality.

The rational design of perfluorinated amphiphiles to control the supramolecular aggregation in an aqueous medium is still a key challenge for the engineering of supramolecular architectures. Here, the synthesis and physical properties of six novel non-ionic amphiphiles are presented. The effect of mixed alkylated and perfluorinated segments in a single amphiphile is also studied and compared with only alkylated and perfluorinated units. To explore their morphological behavior in an aqueous medium, dynamic light scattering (DLS) and cryogenic transmission electron microscopy/electron microscopy (cryo-TEM/EM) measurements are used. The assembly mechanisms with theoretical investigations are further confirmed, using the Martini model to perform large-scale coarse-grained molecular dynamics simulations. These novel synthesized amphiphiles offer a greater and more systematic understanding of how perfluorinated systems assemble in an aqueous medium and suggest new directions for rational designing of new amphiphilic systems and interpreting their assembly process.

Main conclusion Elms, which have received insect eggs as a ‘warning’ of larval herbivory, enhance their anti-herbivore defences by accumulating salicylic acid and amplifying phenylpropanoid-related transcriptional and metabolic responses to hatching larvae. Abstract Plant responses to insect eggs can result in intensified defences against hatching larvae. In annual plants, this egg-mediated effect is known to be associated with changes in leaf phenylpropanoid levels. However, little is known about how trees—long-living, perennial plants—improve their egg-mediated, anti-herbivore defences. The role of phytohormones and the phenylpropanoid pathway in egg-primed anti-herbivore defences of a tree species has until now been left unexplored. Using targeted and untargeted metabolome analyses we studied how the phenylpropanoid pathway of Ulmus minor responds to egg-laying by the elm leaf beetle and subsequent larval feeding. We found that when compared to untreated leaves, kaempferol and quercetin concentrations increased in feeding-damaged leaves with prior egg deposition, but not in feeding-damaged leaves without eggs. PCR analyses revealed that prior insect egg deposition intensified feeding-induced expression of phenylalanine ammonia lyase (PAL), encoding the gateway enzyme of the phenylpropanoid pathway. Salicylic acid (SA) concentrations were higher in egg-treated, feeding-damaged leaves than in egg-free, feeding-damaged leaves, but SA levels did not increase in response to egg deposition alone—in contrast to observations made of Arabidopsis thaliana. Our results indicate that prior egg deposition induces a SA-mediated response in elms to feeding damage. Furthermore, egg deposition boosts phenylpropanoid biosynthesis in subsequently feeding-damaged leaves by enhanced PAL expression, which results in the accumulation of phenylpropanoid derivatives. As such, the elm tree shows similar, yet distinct, responses to insect eggs and larval feeding as the annual model plant A. thaliana.

Polyacetylenes (PAs) are a large group of bioactive phytochemicals, which are primarily produced by higher plants of the families Apiaceae and Araliaceae. Especially aliphatic C17-polyacetylenes of the falcarinol-type such as falcarinol (FaOH) and falcarindiol (FaDOH) are known for their numerous positive effects on human health. In this study we investigate the potential of carrot hairy root cultures for production of PAs. Three individual plants of seven differently coloured carrot cultivars were used for the development of hairy root cultures by transformation of root discs with the wild-type Rhizobium rhizogenes strain 15834. A total of 51 individual hairy root (HR) lines were obtained and quantitatively analysed together with root, petiole and leaf tissue samples for FaOH and FaDOH. Among the five tissues sampled from the donor plants, root periderm samples generally exhibited the highest PA levels with FaDOH as prevailing PA and large differences between cultivars. In comparison to periderm tissue, FaOH levels were highly increased in HR lines of all cultivars. In contrast, FaDOH levels were not significantly altered. Considering the low to moderate PA concentration in root and leaf tissues of the orange cultivars there was an up to more than 10-fold increase of the FaOH concentration in HRs of these genotypes. Within this study a reproducible method for Rrhi-mediated transformation of carrot root discs was applied which provides an efficient tool to assess the function of candidate genes involved in the biosynthesis of key PAs in carrot but might be used in future also for the large-scale production of falcarinol-type PAs.

The mechanical properties of nanoparticles, especially those designed for biomedical purposes, have a large impact on their performance and have been scarcely studied. Thermoresponsive polymer-base...

Nonhost resistance of Arabidopsis thaliana against Phytophthora infestans, a filamentous eukaryotic microbe and the causal agent of potato late blight, is based on a multilayered defense system. Arabidopsis thaliana controls pathogen entry through the penetration-resistance genes PEN2 and PEN3, encoding an atypical myrosinase and an ABC transporter, respectively, required for synthesis and export of unknown indole compounds. To identify pathogen-elicited leaf surface metabolites and further unravel nonhost resistance in Arabidopsis, we performed untargeted metabolite profiling by incubating a P. infestans zoospore suspension on leaves of WT or pen3 mutant Arabidopsis plants. Among the plant-secreted metabolites, 4-methoxyindol-3- yl-methanol and S-(4-methoxy-indol-3-yl-methyl) cysteine were detected in spore suspensions recollected from WT plants, but at reduced levels from the pen3 mutant plants. In both whole-cell and microsome-based assays, 4-methoxyindol-3-yl- methanol was transported in a PEN3-dependent manner, suggesting that this compound is a PEN3 substrate. The syntheses of both compounds were dependent on functional PEN2 and phytochelatin synthase 1. None of these compounds inhibited mycelial growth of P. infestans in vitro. Of note, exogenous application of 4- methoxyindol-3-yl methanol slightly elevated cytosolic Ca2+ levels and enhanced callose deposition in hydathodes of seedlings treated with a bacterial pathogen- associated molecular pattern (PAMP), flagellin (flg22). Loss of flg22-induced callose deposition in leaves of pen3 seedlings was partially reverted by the addition of 4- methoxyindol-3-yl methanol. In conclusion, we have identified a specific indole compound that is a substrate for PEN3 and contributes to the plant defense response against microbial pathogens.

The adsorption of three different polycations at the negatively charged surface of tubular J-aggregates of the amphiphilic cyanine dye 3,3′-bis(2-sulfopropyl)-5,5′,6,6′-tetrachloro-1,1′-dioctylbenzimidacarbocyanine (C8S3) is investigated by means of cryogenic electron microscopy and optical absorption spectroscopy. All three polycations could be adsorbed at the tubular aggregates without flocculation or precipitation when added in molar amounts of monomers sufficiently smaller than that of the dye molecules. It is found that preferably, a minority of aggregates is coated by the polycations while a majority of aggregates is left uncoated. For the coated aggregates, the adsorption leads to charge reversal of the aggregate surface as supported by zeta potential measurements. The morphology of the coating differs significantly for the three polycations: The branched polycation polyethylenimine (PEI) attaches to the tubular aggregate by hit-and-stick adsorption of the coiled state in solution forming irregular clot-like coatings; the flexible and weakly cationic poly (allylamine hydrochloride) (PAH) forms a more homogeneous coating but destroys the integrity of the dye aggregate; the more hydrophobic and strong polycation poly (diallyldimethylammonium chloride) (PDADMAC) forms a thin and homogeneous layer, supposedly by wrapping around the tubular aggregate. For the latter growth of a second double layer of dyes is observed for the aggregates. The different morphologies of the coating layers are explained by the details of the chemical structure of the polycations. The possible adsorption of polyelectrolytes at these amphiphilic tubular structures, stabilized by means of hydrophobic forces, is far from obvious and demonstrates an applicable route to the build-up of more complex nanostructures in solution by means of a self-assembly process.

An understanding of the interactions of 2D nanomaterials with pathogens is of vital importance to developing and controlling their antimicrobial properties. In this work, the interaction of functionalized graphene with tunable hydrophobicity and bacteria is investigated. Poly(ethylene glycol)- block-(poly- N-isopropylacrylamide) copolymer (PEG- b-PNIPAM) with the triazine joint point was attached to the graphene surface by a nitrene [2 + 1] cycloaddition reaction. By thermally switching between hydrophobic and hydrophilic states, functionalized graphene sheets were able to bind to bacteria. Bacteria were eventually disrupted when the functionality was switched to the hydrophobic state. On the basis of measuring the different microscopy methods and a live/dead viability assay, it was found that Escherichia coli ( E. coli) bacteria are more susceptible to hydrophobic interactions than B. cereus bacteria, under the same conditions. Our investigations confirm that hydrophobic interaction is one of the main driving forces at the presented graphene/bacteria interfaces and promotes the antibacterial activity of graphene derivatives significantly.

Enhanced resistance in barley (Hordeum vulgare) against pathogens, such as the powdery mildew-causing fungus Blumeria graminis f. sp. hordei, is of high importance. The beneficial effects of bacterial quorum sensing molecules on resistance and plant growth have been shown in different plant species. Here, we present the effects of the N-3-oxotetradecanoyl-l-homoserine lactone (oxo-C14-HSL) on the resistance of different barley genotypes. Genetically diverse accessions of barley were identified and exposed to the beneficial, oxo-C14-HSL-producing bacterium Ensifer meliloti or the pure N-acyl homoserine lactone (AHL) molecule. Metabolic profiling along with expression analysis of selected genes and physiological assays revealed that the capacity to react varies among different barley genotypes. We demonstrate that upon pretreatment with AHL molecule, AHL-primable barley genotype expresses enhanced resistance against B. graminis f. sp. hordei. We further show that pretreatment with AHL correlates with stronger activation of barley MAP kinases and regulation of defense-related PR1 and PR17b genes after a subsequent treatment with chitin. Noticeable was the stronger accumulation of lignin. Our results suggest that appropriate genetic background is required for AHL-induced priming. At the same time, they bear potential to use these genetic features for new breeding and plant protection approaches.

2D nanomaterials have garnered widespread attention in biomedicine and bioengineering due to their unique physicochemical properties. However, poor functionality, low solubility, intrinsic toxicity, and nonspecific interactions at biointerfaces have hampered their application in vivo. Here, biocompatible polyglycerol units are crosslinked in two dimensions using a graphene‐assisted strategy leading to highly functional and water‐soluble polyglycerols nanosheets with 263 ± 53 nm and 2.7 ± 0.2 nm average lateral size and thickness, respectively. A single‐layer hyperbranched polyglycerol containing azide functional groups is covalently conjugated to the surface of a functional graphene template through pH‐sensitive linkers. Then, lateral crosslinking of polyglycerol units is carried out by loading tripropargylamine on the surface of graphene followed by lifting off this reagent for an on‐face click reaction. Subsequently, the polyglycerol nanosheets are detached from the surface of graphene by slight acidification and centrifugation and is sulfated to mimic heparin sulfate proteoglycans. To highlight the impact of the two‐dimensionality of the synthesized polyglycerol sulfate nanosheets at nanobiointerfaces, their efficiency with respect to herpes simplex virus type 1 and severe acute respiratory syndrome corona virus 2 inhibition is compared to their 3D nanogel analogs. Four times stronger in virus inhibition suggests that 2D polyglycerols are superior to their current 3D counterparts., A 2D hyperbranched polyglycerol and its sulfated counterpart are synthesized using a graphene‐assisted strategy. The synthesized 2D polymers are used to inhibit the infection by severe acute respiratory syndrome corona virus 2 and show an inhibitory concentration as low as 3 nm.

A new series of nonionic gemini amphiphiles have been synthesized in a multi-step chemoenzymatic approach by using a novel A

International audience; The development of tailorable and biocompatible three-dimensional (3D) substrates or molecular networks that reliably mimic the extracellular matrix (ECM) and influence cell behavior and growth in vitro is of increasing interest for cell-based applications in the field of tissue engineering and regenerative medicine. In this context, we present a novel coiled coilbased peptide that self-assembles into a 3D-$\alpha$-helical fibril network and functions as a selfsupporting hydrogel. By functionalizing distinct coiled-coil peptides with cellular binding motifs (RGD) or carbohydrate ligands (mannose), and by utilizing the multivalency and modularity of coiled-coil assemblies, tailored artificial ECMs are obtained. Fibrillar network and ligand density, as well as ligand composition can readily be adjusted by changes in water content or peptide concentrations, respectively. Mesoscopic structure of these networks was assessed by rheology and small-angle neutron scattering experiments. Initial cell viability studies using NIH/3T3 cells showed comparable or even superior cell viability using the presented artificial ECMs, compared to commercially available 3D-cell culture scaffold Matrigel®. The herein reported approach presents a reliable (low batch-to-batch variation) and modular pathway towards biocompatible and tailored artificial ECMs.

Summary As mammals evolved with exposure to particular diets, naturally abundant compounds may have become part of the set of environmental co-determinants that shaped brain structure and function. Here we investigated whether bioactive factors found in apples directly affect hippocampal neurogenesis in the adult mouse. We found that quercetin, the most abundant flavanol in apple peel, was anti-proliferative at high concentrations but pro-neurogenic at low concentrations. This was confirmed in vivo, with intraperitoneally delivered quercetin promoting survival and neuronal differentiation, without affecting proliferation. Using a bioassay-guided fractionation approach we also identified additional pro-neurogenic compounds in apple flesh that were not related to flavonoids. We found that 3,5-dihydroxybenzoic acid significantly increased neural precursor cell proliferation and neurogenesis. This work shows that both flavonoids and 3,5-dihydroxybenzoic acid are pro-neurogenic, not only by activating precursor cell proliferation but also by promoting cell-cycle exit, cellular survival, and neuronal differentiation., Graphical Abstract, Highlights • Quercetin promotes hippocampal precursor cell survival and differentiation • Quercetin induces endogenous antioxidants and the AKT pathway • Apple juice supplementation has no effect on adult neurogenesis or learning • 3,5-Dihydroxybenzoic acid increases precursor cell proliferation and neurogenesis, In this article, Kempermann and colleagues show that quercetin, the most abundant flavonoid in apple peel, promotes hippocampal neurogenesis in the adult mouse brain. They also identify 3,5-dihydroxybenzoic acid as another pro-neurogenic compound found in apple flesh.

Introduction Wheat (Triticum aestivum) it is one of the most important staple food crops worldwide and represents an important resource for human nutrition. Besides starch, proteins and micronutrients wheat grains accumulate a highly diverse set of phytochemicals. Objectives This work aimed at the development and validation of an analytical workflow for comprehensive profiling of semi-polar phytochemicals in whole wheat grains. Method Reversed-phase ultra-high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC/ESI-QTOFMS) was used as analytical platform. For annotation of metabolites accurate mass collision-induced dissociation mass spectra were acquired and interpreted in conjunction with literature data, database queries and analyses of reference compounds. Results Based on reversed-phase UHPLC/ESI-QTOFMS an analytical workflow for comprehensive profiling of semi-polar phytochemicals in whole wheat grains was developed. For method development the extraction procedure and the chromatographic separation were optimized. Using whole grains of eight wheat cultivars a total of 248 metabolites were annotated and characterized by chromatographic and tandem mass spectral data. Annotated metabolites comprise hydroquinones, hydroxycinnamic acid amides, flavonoids, benzoxazinoids, lignans and other phenolics as well as numerous primary metabolites such as nucleosides, amino acids and derivatives, organic acids, saccharides and B vitamin derivatives. For method validation, recovery rates and matrix effects were determined for ten exogenous model compounds. Repeatability and linearity were assessed for 39 representative endogenous metabolites. In addition, the accuracy of relative quantification was evaluated for six exogenous model compounds. Conclusions In conjunction with non-targeted and targeted data analysis strategies the developed analytical workflow was successfully applied to discern differences in the profiles of semi-polar phytochemicals accumulating in whole grains of eight wheat cultivars.

Low biodegradability of graphene derivatives and related health risks are the main limiting factors for their in vivo biomedical applications. Here, we present the synthesis of enzyme-functionalized graphene sheets with self-degrading properties under physiological conditions and their applications in tumor therapy. The synergistic enzyme cascade glucose oxidase and myeloperoxidase are covalently conjugated to the surface of graphene sheets and two-dimensional (2D) platforms are obtained that can produce sodium hypochlorite from glucose. The enzyme-functionalized graphene sheets with up to 289 nm average size are degraded into small pieces (≤40 nm) by incubation under physiological conditions for 24 h. Biodegradable graphene sheets are further loaded with doxorubicin and their ability for tumor therapy is evaluated in vitro and in vivo. The laser-triggered release of doxorubicin in combination with the enzymatic activity of the functionalized graphene sheets results in a synergistic antitumor activity. Taking advantage of their neutrophil-like activity, fast biodegradability, high photo- and chemotherapeutic effects, the novel two-dimensional nanoplatforms can be used for tumor therapeutic applications.

As mammals evolved exposed to particular diets, naturally abundant compounds may have become part of the set of environmental co-determinants that shaped brain structure and function. Here we investigated whether bioactive factors found in apples directly affect hippocampal neural stem cells and promote neurogenesis in the adult mouse. Whereas the consumption of apple juice per se neither altered adult hippocampal neurogenesis nor improved learning and memory, we did find specific direct effects of apple-derived factors on neural stem cell survival and differentiation. Our results revealed that quercetin, the most abundant flavanol in apple peel, was anti-proliferative at high concentrations but acted pro-neurogenically at low concentrations. This was confirmed in vivo, with intraperitoneally-delivered quercetin promoting survival and neuronal differentiation, without affecting proliferation, likely via the PI3 kinase-Akt and Nrf2-Keap1 pathways, respectively. Using a bio-assay-guided fractionation approach with high-resolution collision induced dissociation mass spectroscopy, we also identified additional pro-neurogenic compounds in apple flesh that were not related to flavonoids. In particular, we found that 3,5-dihydroxybenzoic acid, a weak agonist to the lactate receptor, significantly increased both in vitro and in vivo neural precursor cell proliferation and neurogenesis. Altogether, this work shows that both flavonoids and 3,5-dihydroxybenzoic acid are pro-neurogenic, not only by activating precursor cell proliferation but also through promoting cell cycle exit, cellular survival, and neuronal differentiation.

Newer non-ionic amphiphiles have been synthesized using biocompatible materials and by following a greener approach i.e., D-glucitol has been used as a template, and hydrophobic and hydrophilic segments were incorporated on it by using click chemistry. The hydrophilic segments in turn were prepared from glycerol using an immobilized Candida antarctica lipase (Novozym-435)-mediated chemoenzymatic approach. Surface tension measurements and dynamic light scattering studies reflect the self-assembling behavior of the synthesized amphiphilic architectures in the aqueous medium. The results from UV-Vis and fluorescence spectroscopy establish the encapsulation of guests in the hydrophobic core of self-assembled amphiphilic architectures. The results of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay indicate that the amphiphiles are well tolerated by the used A549 cell lines at all tested concentrations.

Newer non-ionic amphiphiles have been synthesized using biocompatible materials and by following a greener approach i.e., D-glucitol has been used as a template, and hydrophobic and hydrophilic segments were incorporated on it by using click chemistry. The hydrophilic segments in turn were prepared from glycerol using an immobilized Candida antarctica lipase (Novozym-435)-mediated chemoenzymatic approach. Surface tension measurements and dynamic light scattering studies reflect the self-assembling behavior of the synthesized amphiphilic architectures in the aqueous medium. The results from UV-Vis and fluorescence spectroscopy establish the encapsulation of guests in the hydrophobic core of self-assembled amphiphilic architectures. The results of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay indicate that the amphiphiles are well tolerated by the used A549 cell lines at all tested concentrations.

Two core–shell nanoparticles with polyglycerol shells and sp3 carbon cores with different flexibilities (soft dendritic polyethylene and hard nanodiamond) were synthesized, their encapsulation capacities were compared, and their ability to transport into tumor cells was investigated. The nanocarrier with a soft core was superior to the hard one.

This report describes the synthesis, structure, and O

Increasing air and soil temperatures and changes in precipitation patterns as consequences of climate change will affect crop production in agricultural ecosystems. The combined effects of soil warming and altered precipitation on the productivity and product quality of oil crops are not yet well studied. Winter oilseed rape (OSR) (Brassica napus L., cv. Mercedes) was field-grown under elevated soil temperature (+2.5 &deg, C), reduced precipitation amount (&minus, 25%), reduced precipitation frequency (&minus, 50%) both separately and in combination in order to investigate effects on crop development, seed yield, and seed quality. Soil warming accelerated crop development during early plant growth and during spring. At maturity, however, plants in all treatments were similar in quantitative (aboveground biomass, seed yield) and qualitative (protein and oil content, amino acids, fatty acids) parameters. We observed the long-term effects of the precipitation manipulation on leaf size, leaf senescence and biomass allocation. Seed yield was not affected by the altered climatic factors, perhaps due to adaptation of soil microorganisms to permanent soil warming and to relatively wet conditions during the seed-filling period. Overall, OSR performed well under moderate changes in soil temperature and precipitation patterns, thus, we observed stable seed yield without negative impacts on nutritive seed quality.

The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process., F for formation: This study introduces systematic fluorination as a tool to investigate the nature of amyloid formation as shown for the model peptide NFGAIL. Modulation of hydrophobicity and the σ‐framework of the Phe residue trough fluorine and iodine led to different amyloid folding kinetics. TEM and SAXS studies revealed the presence of amyloid fibrils.

The syntheses of novel amphiphilic 5,5′,6,6′‐tetrachlorobenzimidacarbocyanine (TBC) dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. For the achiral meso form, a new synthetic route towards asymmetric cyanine dyes was established. All compounds form J aggregates in water, the optical properties of which were characterised by means of spectroscopic methods. The supramolecular structure of the aggregates is investigated by means of cryo‐transmission electron microscopy, cryo‐electron tomography and AFM, revealing extended sheet‐like aggregates for chiral enantiomers and nanotubes for the mesomer, respectively, whereas the conformer forms predominately needle‐like crystals. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry, which in the case of enantiomers enables the formation of extended hydrogen‐bond chains by the hydroxyl functionalities. In case of the achiral meso form, however, such chains turned out to be sterically excluded., Sheets and tubes: The syntheses of amphiphilic 5,5′,6,6′‐tetrachlorobenzimidacarbocyanine dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry.

Multivalent interactions at biological interfaces occur frequently in nature and mediate recognition and interactions in essential physiological processes such as cell-to-cell adhesion. Multivalency is also a key principle that allows tight binding between pathogens and host cells during the initial stages of infection. One promising approach to prevent infection is the design of synthetic or semisynthetic multivalent binders that interfere with pathogen adhesion1–4. Here, we present a multivalent binder that is based on a spatially defined arrangement of ligands for the viral spike protein haemagglutinin of the influenza A virus. Complementary experimental and theoretical approaches demonstrate that bacteriophage capsids, which carry host cell haemagglutinin ligands in an arrangement matching the geometry of binding sites of the spike protein, can bind to viruses in a defined multivalent mode. These capsids cover the entire virus envelope, thus preventing its binding to the host cell as visualized by cryo-electron tomography. As a consequence, virus infection can be inhibited in vitro, ex vivo and in vivo. Such highly functionalized capsids present an alternative to strategies that target virus entry by spike-inhibiting antibodies5 and peptides6 or that address late steps of the viral replication cycle7. Phage capsids modified with spatially defined patterns of host cell ligands can act as multivalent binders for the influenza A virus to prevent viral infection.

Multicomponent self-assembly of peptides is a powerful strategy to fabricate novel functional materials with synergetic properties that can be used for several nanobiotechnological applications. In the present study, we used a coassembly strategy to generate an injectable ultrashort bioactive peptide hydrogel formed by mixing a dipeptide hydrogelator with a macrophage attracting short chemotactic peptide ligand. Coassembly does not impede hydrogelation as shown by cryo-transmission electron microscopy (cryo-TEM), scanning electron microscopy, and rheology. Biocompatibility was shown by cytotoxicity assays and confocal microscopy. The hydrogels release the entrapped skin antibiotic ciprofloxacin, among others, in a slow and continuous manner. Such bioinspired advanced functional materials can find applications as wound dressing materials to treat chronic wound conditions like diabetic foot ulcer.