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BACKGROUND The clinical indications, applications, and effect of the injectable hyaluronic acid range skin quality boosters (SQBs) are different than those of filler products. Material properties are increasingly being discussed for differentiation and in connection with clinical effects and esthetic indications. AIMS The aim of this study is to evaluate whether SQB products can be differentiated from filler products by their physicochemical material properties. MATERIAL AND METHODS Physicochemical properties (extrusion force, swelling degree, rheology, and cohesivity) of two SQBs (BELR , JUVVE ) were compared with those of fillers (BELB , JUVVT ) using the same manufacturing technology. RESULTS Cohesivity was almost equal for SQBs and fillers. Few statistically significant differences in physicochemical properties were found. Properties of SQBs differed from fillers mainly in their delta of rheological properties and extrusion force. CONCLUSION In this study, physicochemical differences between SQB and filler were determined and described, supporting the presence of two categories and their different clinical indications and applications.

Atom‐transfer radical addition (ATRA) reactions have gained a strong foothold in organic synthesis by virtue of their operational simplicity, synthetic versatility, and perfect atom economy. A rich chemical space can be accessed through clever combinations of the simple starting materials. Many variations of this general motif have been reported. However, the vast majority involve the addition of an organic halide across a C=C double bond, resulting in the formation of 1,2‐bifunctional products. This report introduces a significant expansion of this general reactivity concept to give 1,3‐bifunctional adducts through the combination of 1,1‐ATRA to a carbenoid and 1,2‐ATRA to an alkyne. Both processes operate under mild conditions (RT, 5 h) with the same commercial catalyst (CoBr2, dppbz)., 2+1 ATRA: A three‐component radical addition reaction between alkyl halides, TMSCHN2, and alkynes under mild conditions (RT, 5 h) with a commercial catalyst (CoBr2, dppbz) has been developed. This constitutes a significant extension of conventional (two‐component) atom‐transfer radical addition (ATRA) reactions through the incorporation of a carbenoid precursor, which results in an overall 1,3‐functionalization.

Hit‐to‐lead optimization is a critical phase in drug discovery. Herein, we report on the fragment‐based discovery and optimization of 2‐aminopyridine derivatives as a novel lead‐like structure for the treatment of the dangerous opportunistic pathogen Pseudomonas aeruginosa. We pursue an innovative treatment strategy by interfering with the Pseudomonas quinolone signal (PQS) quorum sensing (QS) system leading to an abolishment of bacterial pathogenicity. Our compounds act on the PQS receptor (PqsR), a key transcription factor controlling the expression of various pathogenicity determinants. In this target‐driven approach, we made use of biophysical screening via surface plasmon resonance (SPR) followed by isothermal titration calorimetry (ITC)‐enabled enthalpic efficiency (EE) evaluation. Hit optimization then involved growth vector identification and exploitation. Astonishingly, the latter was successfully achieved by introducing flexible linkers rather than rigid motifs leading to a boost in activity on the target receptor and anti‐virulence potency., Growth vector identification and exploitation: Enthalpic efficiency‐driven fragment prioritization led to 2‐aminopyridines as starting points for the generation of novel pathoblockers against P. aeruginosa. Allowing flexibility in the hit optimization process facilitated successful fragment growing accompanied by a thousand‐fold boost in activity relative to the initial fragment.

Extracellular vesicles (EVs) from several body fluids, including urine, appear as promising biomarkers. Within the last decade, numerous groups have compared the efficacy of EV preparation protocols. Frequently, the efficacy of EV preparation methods is judged by the recovery of particles as estimated by conventional nanoparticle tracking analysis (NTA) or other particle quantification devices. Here, at the example of different urinary EV (uEV) preparation methods, we determined the particle yield in obtained samples with conventional NTA, analyzed their EV content by imaging flow cytometry (IFCM) and quantified the intensity of TSG101 and the contaminant protein uromodulin (UMOD) in Western blots. Our results demonstrate a correlation among CD9-positive objects detected by IFCM and TSG101 Western blot intensities, while particle numbers as determined by NTA correlated with the amount of UMOD.Consequently, our results question the reliability of conventional NTA analyses for identifying the optimal EV preparation method. Here, in our method comparison, a combination of size exclusion chromatography followed by ultra-filtration showed the highest CD9-positive object and TSG101 protein recovery, and in relation to the number of CD9-positive objects, the lowest amount of UMOD contamination.

Functional inhibitors of acid sphingomyelinase are clinically used as anti-depressants since ∼60 years. Here, we show that acid sphingomyelinase inhibition by the antidepressants amitriptyline, fluoxetine and desipramine protects from ischemia/reperfusion and elicits a profound brain remodeling response with increased angiogenesis, improved blood-brain barrier integrity, reduced brain leukocyte infiltration and increased neuronal survival. Angiogenesis is promoted by small extracellular vesicles with bona fide characteristics of exosomes, which are released from endothelial cells and which constitute an elegant target for the amplification of stroke recovery.

Small extracellular vesicles isolated from urine (uEVs) are increasingly recognized as potential biomarkers. Meanwhile, different uEV preparation strategies exist. Conventionally, the performance of EV preparation methods is evaluated by single particle quantification, Western blot, and electron microscopy. Recently, we introduced imaging flow cytometry (IFCM) as a next-generation single EV analysis technology. Here, we analyzed uEV samples obtained with different preparation procedures using nanoparticle tracking analysis (NTA), semiquantitative Western blot, and IFCM. IFCM analyses demonstrated that urine contains a predominant CD9+ sEV population, which exceeds CD63+ and CD81+ sEV populations. Furthermore, we demonstrated that the storage temperature of urine samples negatively affects the recovery of CD9+ sEVs. Although overall reduced, the highest CD9+ sEV recovery was obtained from urine samples stored at −80 °C and the lowest from those stored at −20 °C. Upon comparing the yield of the different uEV preparations, incongruencies between NTA and IFCM data became apparent. Results obtained by both NTA and IFCM were consistent with Western blot analyses for EV marker proteins, however, NTA results correlated with the amount of the impurity marker uromodulin. Despite demonstrating that the combination of ultrafiltration and size exclusion chromatography appears as a reliable uEV preparation technique, our data challenge the soundness of traditional NTA for the evaluation of different EV preparation methods.

Obtained from the right cell-type, mesenchymal stromal cell (MSC)-derived small extracellular vesicles (sEVs) promote stroke recovery. Within this process, microvascular remodeling plays a central role. Herein, we evaluated the effects of MSC-sEVs on the proliferation, migration, and tube formation of human cerebral microvascular endothelial cells (hCMEC/D3) in vitro and on post-ischemic angiogenesis, brain remodeling and neurological recovery after middle cerebral artery occlusion (MCAO) in mice. In vitro, sEVs obtained from hypoxic (1% O2), but not ‘normoxic’ (21% O2) MSCs dose-dependently promoted endothelial proliferation, migration, and tube formation and increased post-ischemic endothelial survival. sEVs from hypoxic MSCs regulated a distinct set of miRNAs in hCMEC/D3 cells previously linked to angiogenesis, three being upregulated (miR-126-3p, miR-140-5p, let-7c-5p) and three downregulated (miR-186-5p, miR-370-3p, miR-409-3p). LC/MS–MS revealed 52 proteins differentially abundant in sEVs from hypoxic and ‘normoxic’ MSCs. 19 proteins were enriched (among them proteins involved in extracellular matrix–receptor interaction, focal adhesion, leukocyte transendothelial migration, protein digestion, and absorption), and 33 proteins reduced (among them proteins associated with metabolic pathways, extracellular matrix–receptor interaction, focal adhesion, and actin cytoskeleton) in hypoxic MSC-sEVs. Post-MCAO, sEVs from hypoxic MSCs increased microvascular length and branching point density in previously ischemic tissue assessed by 3D light sheet microscopy over up to 56 days, reduced delayed neuronal degeneration and brain atrophy, and enhanced neurological recovery. sEV-induced angiogenesis in vivo depended on the presence of polymorphonuclear neutrophils. In neutrophil-depleted mice, MSC-sEVs did not influence microvascular remodeling. sEVs from hypoxic MSCs have distinct angiogenic properties. Hypoxic preconditioning enhances the restorative effects of MSC-sEVs. Supplementary Information The online version contains supplementary material available at 10.1007/s00395-021-00881-9.

An ex-situ aging study was carried out using commercial lithium-ion battery cells with lithium nickel cobalt aluminum oxide (NCA) positive electrodes and aluminum oxide (Al2O3) surface coated graphitic negative electrodes at various states of health (SOHs): 100%, 80% and 10%. The lowest SOH-value was chosen in order to understand and to quantify the aging mechanisms in lithium-ion batteries. The electrodes were analyzed by different techniques: SEM/EDX, ICP-OES, XPS, XRD and BET. Significant changes in positive and negative morphology, elemental composition and surface area were observed depending on the SOH value and the positioning of the sample in the jelly roll. We discuss in the context of well-known aging mechanisms further aging effects. The cell capacity is limited by the amount of immobilized lithium. Lithium loss of the positive electrode is directly correlated with a lithium increase of the negative electrode. The linearity of the lithium content in the electrodes is a function of SOH over the whole SOH-range while the lithium content in the electrodes is an exponential function of the porosity. Another aging effect is the degradation of the ceramic coating on the graphite and the migration of the ceramic coating from the surface of the negative electrode to the bulk.

Mesenchymal stem/stromal cells (MSCs) provide therapeutic effects in many diseases. Contrary to initial hypotheses, they act in a paracrine rather than a cellular manner. To this end, extracellular vesicles (EVs) have been found to mediate the therapeutic effects, even when harvested from MSC-conditioned cell culture supernatants. Lacking self-replicating activity and being so small that MSC-EV preparations can be sterilized by filtration, EVs provide several advantages as therapeutic agents over cellular therapeutics. At present, methods allowing EV preparation from larger volumes are scarce and regularly require special equipment. We have developed a polyethylene glycol-based precipitation protocol allowing extraction of EVs from several liters of conditioned medium. MSC-EVs prepared with this method have been successfully applied to a human graft-versus-host disease patient and to several animal models. Although the method comes with its own limitations, it is extremely helpful for the initial evaluation of EV-based therapeutic approaches. Here, we introduce the technique in detail and discuss all critical steps. © 2020 The Authors. Basic Protocol 1: Preparation of MSC-conditioned medium for scaled MSC-EV production Basic Protocol 2: PEG precipitation OF MSC-EV from MSC-conditioned medium.

Objectives In the context of cystic fibrosis, Pseudomonas aeruginosa biofilms often develop in the vicinity of airway mucus, which acts as a protective physical barrier to inhaled matter. However, mucus can also adsorb small drug molecules administered as aerosols, including antibiotics, thereby reducing their bioavailability. The efficacy of antibiotics is typically assessed by determining the MIC using in vitro assays. This widespread technique, however, does not consider either bacterial biofilm formation or the influence of mucus, both of which may act as diffusion barriers, potentially limiting antibiotic efficacy. Methods We grew P. aeruginosa biofilms in the presence or absence of human tracheal mucus and tested their susceptibility to tobramycin and colistin. Results A significant reduction of tobramycin efficacy was observed when P. aeruginosa biofilms were grown in the presence of mucus compared with those grown in the absence of mucus. Diffusion of tobramycin through mucus was reduced; however, this reduction was more pronounced in biofilm/mucus mixtures, suggesting that biofilms in the presence of mucus respond differently to antibiotic treatment. In contrast, the influence of mucus on colistin efficacy was almost negligible and no differences in mucus permeability were observed. Conclusions These findings underline the important role of mucus in the efficacy of anti-infective drugs.

Flooded lead acid batteries that had been cycled under micro-hybrid conditions at −5 °C, 3 °C, 27 °C and 60 °C were torn down and investigated by scanning electron microscopy (SEM) and sulfate analysis, both on the surface and in the bulk. The results are correlated with acid density measurements that have been published earlier [10]. As a result, it is confirmed that the extent of concentration gradients in flooded lead-acid batteries (i.e. acid stratification) is strongly dependent from temperature. Locally higher acid concentrations at stratification will be consumed by local sulfation of negative active mass during partial state of charge cycling causing premature aging of these plate areas.

A series of alkynyl aryl conjugated aldehydes and imines were prepared and their adducts with various Lewis acidic boranes have been studied via NMR, absorption, and luminescence spectroscopies in solution. The imine-B(C6F5)3 adduct showed remarkable solution stability, and was then trialled in vapochromism experiments using simple impregnated paper strips to examine the fluorescence responses.

We describe the synthesis of 1,1'- and 2,2'-bicarbazoles by oxidative homocoupling of 2- and 1-hydroxycarbazoles. The oxidative coupling using catalytic amounts of F16 PcFe can be applied to both groups of substrates. Although F16 PcFe generally provides the best yields for the synthesis of 1,1'-bicarbazoles, di-tert-butyl peroxide affords better results for the 2,2'-bicarbazoles. In our study, we have achieved the first syntheses of the biscarbalexines A-C, bisglybomine B, 2,2'-dihydroxy-7,7'-dimethoxy-3,3'-dimethyl-1,1'-bicarbazole, bispyrayafoline C, and bisisomahanine. The iron-catalyzed coupling of koenigine led to an improved synthesis of 8,8''-biskoenigine and afforded an unprecedented decacylic product. Oxidative coupling of 1-hydroxycarbazoles led to bisclausenol, and to the first total syntheses of bismurrayafoline B and D.

A series of 49 oxygenated tricyclic carbazole derivatives has been tested for inhibition of the growth of Mycobacterium tuberculosis and a mammalian cell line (vero cells). From this series, twelve carbazoles showed a significant anti-TB activity. The four most active compounds were the naturally occurring carbazole alkaloids clauszoline-M (45), murrayaline-C (41), carbalexin-C (27), and the synthetic carbazole derivative 22 with MIC90 values ranging from 1.5 to 3.7μM. The active compounds were virtually nontoxic for the mammalian cell line in the concentration range up to 50μM.

Enhanced flooded batteries were studied by means of spatially resolved Raman spectroscopy. Negative plate sulfation as an important failure mode in partial state of charge cycling was characterized. Raman spectroscopy turned out to be an appropriate method for sulfation analysis. The data were correlated with results from elementary analysis and EDX. A lead sulfate specific mapping along electrode cross-section was possible with a spatial resolution of ∼50 μm.

Current endocrine therapeutics for the estrogen-dependent disease endometriosis often lead to considerable side-effects as they act by reducing estrogen action systemically. A more recent approach takes advantage of the fact that the weak estrogen estrone (E1) which is abundant in the plasma, is activated in the target cell to the highly estrogenic estradiol (E2) by 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). 17β-HSD1 is overexpressed in endometriosis and thus a promising target for the treatment of this disease, with the prospect of less target-associated side-effects. Potent inhibitors from the class of bicyclic substituted hydroxyphenylmethanones with sulfonamide moiety recently described by us suffered from high molecular weight and low selectivity over 17βHSD2, the physiological adversary of 17β-HSD1. We describe the structural optimizations leading to the discovery of (5-(3,5-dichloro-4-methoxyphenyl)thiophen-2-yl)(2,6-difluoro-3-hydroxyphenyl)methanone 20, which displayed a sub-nanomolar IC50 towards 17β-HSD1 as well as high selectivity over the type 2 enzyme, the estrogen receptors α and β and a range of hepatic CYP enzymes. The compound did neither show cellular toxicity, nor PXR activation nor mutagenicity in the AMES II assay. Additional favourable pharmacokinetic properties (rat) make 20 a suitable candidate for proof-of-principle studies using xenotransplanted immunodeficient rats.

Estrogens are the major female sex steroid hormones, estradiol (E2) being the most potent form in humans. Disturbing the balance between E2 and its weakly active oxidized form estrone (E1) leads to diverse types of estrogen-dependent diseases such as endometriosis or osteoporosis. 17β-Hydroxysteroid dehydrogenase type 1 (17β-HSD1) catalyzes the biosynthesis of E2 by reduction of E1 while the type 2 enzyme catalyzes the reverse reaction. Thus, 17β-HSD1 and 17β-HSD2 are attractive targets for treatment of estrogen-dependent diseases. Recently, we reported the first proof-of-principle study of a 17β-HSD2 inhibitor in a bone fracture mouse model, using subcutaneous administration. In the present study, our aim was to improve the in vitro ADME profile of the most potent 17β-HSD1 and 17β-HSD2 inhibitors described so far. The optimized compounds show strong and selective inhibition of both the human enzymes and their murine orthologs. In addition, they display good metabolic stability in human liver microsomes (S9 fraction), low in vitro cytotoxicity as well as better aqueous solubility and physicochemical properties compared to the lead compounds. These achievements make the compounds eligible for testing in preclinical in vivo animal model studies on the effects of inhibition of 17β-HSD1 and 17β-HSD2.

Current therapies of steroid hormone-dependent diseases predominantly alter steroid hormone concentrations (or their actions) in plasma, in target and nontarget tissues alike, rather than in target organs only. Targeted therapy through the inhibition of steroidogenic enzymes may pose an attractive alternative with much less side effects. Here, we describe the design of a nanomolar potent 17β-hydroxysteroid dehydrogenase type 2 (17β-HSD2) inhibitor (compound 15) and successful targeted intracrine therapy in a mouse bone fracture model. Blockade of 17β-HSD2 in bone is thought to increase intracellular estradiol (E2) and testosterone (T), which thereby inhibits bone resorption by osteoclasts and stimulates bone formation by osteoblasts, respectively. Administration of compound 15 in the mouse fracture model strongly increases the mechanical stability of the healing fractured bone because of a larger periosteal callus with newly formed bone without changing the plasma E2 and T concentrations. Steroidogenic 17β-HSD2 inhibition thus enables targeted intracrine therapy.

In article number 2004369, Martin Empting and colleagues describe a new generation of dual‐loaded nanoparticles enabling efficient eradication of Pseudomonas aeruginosa biofilms. The squalene‐based nanocarrier facilitates co‐delivery of a novel pathogenspecific Quorum Sensing Inhibitor (QSI) together with the standard‐of‐care antibiotic tobramycin. The QSI itself shows high anti‐virulence efficacy, favorable DMPK and no overt safety pharmacology. When applied as the nanoparticle formulation the QSI potentiates biofilm eradication capabilities of tobramycin by at least 32‐fold. [Image: see text]

Pseudomonas aeruginosa (PA) infections can be notoriously difficult to treat and are often accompanied by the development of antimicrobial resistance (AMR). Quorum sensing inhibitors (QSI) acting on PqsR (MvfR) – a crucial transcriptional regulator serving major functions in PA virulence – can enhance antibiotic efficacy and eventually prevent the AMR. An integrated drug discovery campaign including design, medicinal chemistry‐driven hit‐to‐lead optimization and in‐depth biological profiling of a new QSI generation is reported. The QSI possess excellent activity in inhibiting pyocyanin production and PqsR reporter‐gene with IC50 values as low as 200 and 11 × 10−9 m, respectively. Drug metabolism and pharmacokinetics (DMPK) as well as safety pharmacology studies especially highlight the promising translational properties of the lead QSI for pulmonary applications. Moreover, target engagement of the lead QSI is shown in a PA mucoid lung infection mouse model. Beyond that, a significant synergistic effect of a QSI‐tobramycin (Tob) combination against PA biofilms using a tailor‐made squalene‐derived nanoparticle (NP) formulation, which enhance the minimum biofilm eradicating concentration (MBEC) of Tob more than 32‐fold is demonstrated. The novel lead QSI and the accompanying NP formulation highlight the potential of adjunctive pathoblocker‐mediated therapy against PA infections opening up avenues for preclinical development., The discovery and profiling of a novel Pseudomonas aeruginosa‐targeting Quorum Sensing Inhibitor (QSI) with high anti‐virulence efficacy, favorable DMPK and no overt safety pharmacology is reported. The in vivo target engagement of the lead QSI in a mucoid lung‐infection mouse model is demonstrated. Importantly, the application of a state‐of‐the‐art squalene‐based nanocarrier formulation boosts tobramycin susceptibility of biofilms.

Anticalins engineered for high affinity and specificity towards the central VFFAED epitope in Aβ peptides potently inhibit their aggregation, thus providing novel reagents to study the molecular pathology of Alzheimer's disease (AD) and alternative drug candidates compared with current biopharmaceutical treatments., Amyloid beta (Aβ) peptides, in particular Aβ42 and Aβ40, exert neurotoxic effects and their overproduction leads to amyloid deposits in the brain, thus constituting an important biomolecular target for treatments of Alzheimer's disease (AD). We describe the engineering of cognate Anticalins as a novel type of neutralizing protein reagent based on the human lipocalin scaffold. Phage display selection from a genetic random library comprising variants of the human lipocalin 2 (Lcn2) with mutations targeted at 20 exposed amino acid positions in the four loops that form the natural binding site was performed using both recombinant and synthetic target peptides and resulted in three different Anticalins. Biochemical characterization of the purified proteins produced by periplasmic secretion in Escherichia coli revealed high folding stability in a monomeric state, with Tm values ranging from 53.4°C to 74.5°C, as well as high affinities for Aβ40, between 95 pM and 563 pM, as measured by real-time surface plasmon resonance analysis. The central linear VFFAED epitope within the Aβ sequence was mapped using a synthetic peptide array on membranes and was shared by all three Anticalins, despite up to 13 mutual amino acid differences in their binding sites. All Anticalins had the ability–with varying extent–to inhibit Aβ aggregation in vitro according to the thioflavin-T fluorescence assay and, furthermore, they abolished Aβ42-mediated toxicity in neuronal cell culture. Thus, these Anticalins provide not only useful protein reagents to study the molecular pathology of AD but they also show potential as alternative drug candidates compared with antibodies.

The aging of graphite anodes in prismatic lithium ion cells during a low temperature pulse charging regime was studied by electrical tests and post-mortem analysis. The capacity decrease and impedance increase mainly occurs in the beginning of cycling and lithium plating was identified as the major aging mechanism. The degradation and the local states of charge show an inhomogeneous distribution over the anode, which is confirmed from spatially resolved XRD studies and SEM combined with EDX performed on electrode cross sections. Comparing a charged cell with a discharged cell reveals that ca. 1/3 of the lithium is plated reversibly at the given SOH of 60%. It is proposed that high charge rates at low temperatures induce inhomogeneities of temperature and anode utilization resulting in inhomogeneous aging effects that accumulate over lifetime.

After completion of an exploration well, sandstones of the Exter Formation were hydraulically tested to determine the hydraulic properties and to evaluate chemical and microbial processes caused by drilling and water production. The aim was to determine the suitability of the formation as a reservoir for aquifer thermal energy storage. The tests revealed a hydraulic conductivity of 1–2 E-5 m/s of the reservoir, resulting in a productivity index of 0.6–1 m3/h/bar. A hydraulic connection of the Exter Formation to the overlaying, artesian “Rupelbasissand” cannot be excluded. Water samples were collected for chemical and microbiological analyses. The water was similarly composed as sea water with a maximum salinity of 24.9 g/L, dominated by NaCl (15.6 g/L Cl and 7.8 g/L Na). Until the end of the tests, the water was affected by drilling mud as indicated by the high pH (8.9) and high bicarbonate concentration (359 mg/L) that both resulted from the impact of sodium carbonate (Na2CO3) additives. The high amount of dissolved organic matter (> 58 mg/L) and its molecular-weight distribution pattern indicated that residues of cellulose, an ingredient of the drilling mud, were still present at the end of the tests. Clear evidence of this contamination gave the measured uranine that was added as a tracer into the drilling mud. During fluid production, the microbial community structure and abundance changed and correlated with the content of drilling mud. Eight taxa of sulfate-reducing bacteria, key organisms in processes like bio-corrosion and bio-clogging, were identified. It can be assumed that their activity will be affected during usage of the reservoir.

Seit der Beschreibung, dass sich mesenchymale Stamm- bzw. Stromazellen (MSC) des Menschen in verschiedene Zelltypen differenzieren konnen bzw. immunmodulierende Effekte vermitteln, sind sie in mehr als 500 beim NIH registrierten Studien zur Behandlung verschiedenster Erkrankungen eingesetzt worden. Allem Anschein nach erzielen sie ihre therapeutische Wirkung jedoch nicht wie lange angenommen durch die Integration in betroffene Gewebe, sondern durch die Freisetzung parakriner Faktoren, insbesondere durch extrazellulare Vesikel (EV) wie Exosomen und Mikrovesikel. EV stellen extrazellulare Organellen dar, die sehr spezifisch interzellulare Kommunikation auch uber grosere Distanzen hinweg vermitteln, von verschiedensten Zellen abgegeben werden und in samtlichen Korperflussigkeiten nachweisbar sind. Sie besitzen einen heterogenen Gehalt an Lipiden, Proteinen und nicht kodierenden RNA-Molekulen. Als nicht selbstreplizierende Einheiten, die sich steril filtrieren lassen, weisen sie fur therapeutische Anwendungen prinzipiell nennenswerte Vorteile gegenuber Zellen auf. Neben verschiedenen praklinischen Modellen wurden aus MSC-Kulturuberstanden gewonnene EV bereits in einem ersten individuellen Heilversuch zur Behandlung einer steroidrefraktaren Graft-versus-Host-Disease (GvHD)-Patientin eingesetzt. Sowohl in den bislang durchgefuhrten praklinischen Versuchen als auch in der behandelten GvHD-Patientin liesen sich nach MSC-EV-Applikation vielversprechende therapeutische Effekte beobachten, ohne erkennbare Nebenwirkungen hervorzurufen. MSC-EV erfullen somit allem Anschein nach wichtige Voraussetzungen, um als neues Behandlungsmittel in der Immuntherapie und der regenerativen Medizin in Betracht gezogen zu werden.

Reversed‐phase high‐performance liquid chromatography (RP‐HPLC) has been carried out for a series of unsubstituted polycyclic aromatic hydrocarbons (PAHs) and the corresponding ethynyl, 1,3‐butadiynyl, and 1,3,5‐hexatriynyl derivatives. Theoretical values of the isotropic polarizability and several polarity descriptors have been computed for each compound by using semiempirical models and density functional theory (DFT), with the aim of evaluating linear functions as quantitative structure–retention relationships (QSRRs). The polarity has been described by using either the permanent electric dipole moment, the subpolarity, or a topological electronic index. Three types of partial atomic charges have been used to calculate the subpolarity and a topological index. The choice of the theoretical model, of the polarity descriptor, and of the partial atomic charges is discussed and the resulting QSRRs are compared. Calculating the retention times from the polarizability and the topological electronic index (AM1, PM3, or DFT‐B3LYP/6–31+G(d,p)) gives the best agreement with the experimental values.

A methodology is presented to quantify acid stratification in flooded lead acid batteries and compare different types of batteries regardless of their design features and size by means of the proposed “stratifiability index”. This index describes to what degree acid stratification develops in flooded lead acid batteries. Different test procedures are proposed which induce severe acid stratification within 48 h and lead to significantly different degrees of acid stratification. The test procedures are intended to assist in the development and selection of batteries which are less prone to develop severe acid stratification.

Hyperpolarization activated and cyclic nucleotide-gated (HCN) ion channels as well as cyclic nucleotide-gated (CNG) ion channels are essential for the regulation of cardiac cells, neuronal excitability, and signaling in sensory cells. Both classes are composed of four subunits. Each subunit comprises a transmembrane region, intracellular N- and C-termini, and a C-terminal cyclic nucleotide-binding domain (CNBD). Binding of cyclic nucleotides to the CNBD promotes opening of both CNG and HCN channels. In case of CNG channels, binding of cyclic nucleotides to the CNBD is sufficient to open the channel. In contrast, HCN channels open upon membrane hyperpolarization and their activity is modulated by binding of cyclic nucleotides shifting the activation potential to more positive values. Although several high-resolution structures of CNBDs from HCN and CNG channels are available, the gating mechanism for murine HCN2 channel, which leads to the opening of the channel pore, is still poorly understood. As part of a structural investigation, here, we report the complete backbone and side chain resonance assignments of the murine HCN2 CNBD with part of the C-linker.

A Buchwald–Hartwig amination and palladium(II)-catalyzed oxidative cyclization reaction sequence provided efficient access to a series of oxygenated tricyclic carbazoles. In the present work, this approach was applied to the total syntheses of the naturally occurring carbazole alkaloids 2-hydroxy-7-methylcarbazole, glycozolicine, mukoline, mukolidine, sansoakamine, glycozolidine, clausine-H (clauszoline-C), clausine-K (clauszoline-J), and methyl 2-hydroxy-7-methoxycarbazole-3-carboxylate, which was originally proposed as the structure of clausine-TY. The synthesis of the latter led to the structural reassignment of clausine-TY.

We report the first total synthesis of murrastifoline B and an improved route to murrastifoline F using a twofold palladium-catalyzed Buchwald–Hartwig amination as key step. The mono­meric carbazole and the biaryl precursor are also prepared via ­palladium-catalyzed coupling reactions.

Typically, SNAr reactions at 4-chloro-2-methylthiopyrimidine are carried out employing DMF and sodium hydride under inert gas as well as prolonged reaction times. Herein, we describe a mild and rapid microwave-assisted synthesis to achieve 4-substituted 2-methylthiopyrimidnes from the corresponding chlorine precursor. Moderate to excellent yields were obtained in a green chemistry fashion requiring only few minutes of reaction time.

Background & Aim Human mesenchymal stem/stromal cells (MSCs) have been applied in more than 900 NIH-registered clinical trials with different outcomes. In a proportion of studies pro-regenerative and/or immunomodulatory therapeutic effects were observed. Against the initial assumption, preclinical data demonstrated that – if functional - MSCs act in a paracrine rather than in a cellular manner. Efforts to search for the active paracrine components ended in the identification of extracellular vesicle (EVs). Indeed, in several preclinical models EVs harvested from MSC conditioned media exerted comparable therapeutic effects than the MSCs themselves. Methods, Results & Conclusion EVs released by virtually all cell types represent a heterogenous population of vesicles of different origin, including exosomes (70-150 nm), microvesicles (100-1000 nm), and apoptotic bodies (> 500 nm). Classically, they are prepared by differential centrifugation. Due to volume restricitions during ultracentrifugation only smaller amounts of EV containing liquids can be processed with this method. To efficiently translate MSC-EVs into the clinics, they need to be produced in a scaled manner. Previously, we established and successfully used a polyehtylen glycol (PEG) precipitation procedure allowing to process up to 10 l conditioned medium. Intending to further scale the MSC-EV production, optimally in a closed system, we have started to optimize tangential flow filtration (TFF) protocols, in principal being scalable up to several 1000 litres. At first, we compared different TFF devices and selected the holofiber-based TFF system. Although EVs can efficiently be prepared from serum-free conditioned media, the processing of serum or human platelet lysate (hPL) containing conditioned media remains challenging. The high protein content of serum and hPL supplemented media quickly results in protein aggregate formation and clogging of the pores of the TFF system, which negatively affect the EV purification process. Currently, by changing flow rates and and re-addition of buffers, we optimize the TFF protocols to enable us obtaining MSC-EV preparations with comparable purities than with the PEG method.

Background & Aim Extracellular vesicles (EVs), such as exosomes and microvesicles, are shed by all cell types and found in all body fluids. EVs transmit specific information from their cells of origin to specific target cells and are key factors in a novel form of intercellular communication. Depending on their origin, EVs can modulate immune responses and either act proinflammatory (e.g. mature DC-EVs) or anti-inflammatory (e.g. mesenchymal stem cell (MSC) and many tumor cell-derived EVs). Methods, Results & Conclusion Aiming to analyze immune-modulating properties of EVs from different sources, in vitro, we established a novel form of a mixed lymphocyte reaction (MLR) assay. Here, human peripheral blood-derived mononuclear cells (MNCs) were pooled from up to 12 different healthy donors warranting high cross-reactivity, even following an optimized freezing and thawing procedure. After thawing, mixed MNCs are cultured for 5 days in the absence or presence of EVs. Thereafter, cell morphologies are documented and cells are phenotypically characterized by flow cytometry. By analyzing the expression of a collection of different lineage and activation markers, we selected a panel of antigens apparently being regulated by therapeutically active MSC-EVs. For example we observed that in the presence of active MSC-EVs more CD14+ (monocytes) and CD56+ (natural killer cells) are recovered from the MLR than in corresponding control samples. In contrast, in the presence of active MSC-EVs contents of CD4+ and CD8+ T cells got slightly decreased. Focusing on T cells, we learned that active MSC-EVs reduced the content of CD4 and CD8 T cells expressing T cell activation markers like CD54 and CD25. Currently, we compare the immunomodulatory capabilities of EVs of different cell types. Furthermore, we proceed in optimizing the marker panel to distinguish immune cell subtypes such as the different types of CD4+ cell types (T 1, T 2, T 17 and T).

Neue Fahrzeugtechnologien mit Mikro-Hybrid-Konzepten, die uber Start-Stopp-Funktion und regeneratives Bremsen verfugen, stellen erhohte Anforderungen an die Blei-Saure-Starterbatterie. Die sich wahrend der Start-Stopp-Zyklen im Fahrzeug bei Batterien mit flussigen Elektrolyten einstellende inhomogene Sauredichteverteilung fuhrt zu einer inhomogenen Stromverteilung. Passive Mischelemente zeigen hohe Wirksamkeit beim Ausgleich von Sauredichteunterschieden innerhalb des Elektrolyten. Zur Beurteilung der Wirksamkeit von Mischelementen im Fahrzeugbetrieb wurden weiterentwickelte Blei-Saure-Nassbatterien in Fahrzeugen gealtert. Dabei wurden Innenwiderstandsverlaufe und Ladezustandsanderungen verfolgt. Die Untersuchung zeigte, dass sich passive Mischelemente fur den Einsatz in Fahrzeugen mit Start-Stopp-Funktion eignen. New automotive technologies such as micro hybrid solutions that come with a start-stop and a regenerative breaking system place higher demands on the lead acid starter battery. The inhomogeneous acid density distribution that occurs with batteries comprising flooded electrolyte during the start-stop cycles of the vehicle results in an inhomogeneous current distribution. Passive mixing elements can be used to counterbalance the different acid densities within the electrolyte. This approach is highly effective. Flooded lead-acid batteries were improved and aged in the vehicle to assess the effectiveness of mixing elements during vehicle operation. The internal resistance and changes of the state of charge were evaluated. The investigation showed that passive mixing elements can be used for vehicles with a start-stop system.

In micro-hybrid vehicles, the starter battery is subject to heavy cyclic loads. Results of these cyclic loads are vertical concentration gradients (acid stratification). For this study, it was analyzed systematically how different temperatures influence the formation and reduction of acid stratification. To this end, flooded lead-acid batteries were cycled during a cycle test with 17.5% depth of discharge at −5 °C, 3 °C, 27 °C, and 60 °C. To determine the extent of acid stratification caused by the cycling, the acid density values of the test batteries cycled at four different temperatures were measured using acid density monitoring. The acid densities were measured hourly in 0%, 15%, 30%, 45%, 60%, 80%, and 100% sections in the direction of the perpendicular z-axis of the battery. The measurements showed that the extent of acid concentration gradients is dependent on the temperature, with acid stratification caused by an uneven distribution of current over the height of the plates. Furthermore, it was established that battery discharging as well as battery charging causes an inhomogeneous acid density distribution in the battery electrolyte.

Micro-hybrid vehicles with stop–start function and regenerative braking lead to higher requirements on flooded lead-acid batteries. A promising approach to improve the cycleability of flooded lead-acid batteries is the use of carbon additives in the negative active mass. In this study different carbons (carbon blacks and a lamp black) were studied by transmission electron microscopy and Raman spectroscopy. Furthermore, batteries containing carbon blacks and lamp black in the negative active material were cycled with 17.5% depth of discharge. Morphology, surface functionalisation, and the degree of order were correlated with the cycle life. In cycling tests, batteries with highly ordered carbon blacks increase the lifetime of the corresponding battery by up to a factor of two.

Using a palladium(II)-catalysed oxidative cyclisation as key step, we describe a highly efficient total synthesis of a series of naturally occurring 1,6-dioxygenated carbazole alkaloids: clausenine, 6-methoxymurrayanine, clausenol, clausine G, clausine I, clausine Z and methyl 1,6-dihydroxy-9H-carbazole-3-carboxylate.

A systematic study of room temperature 57 Fe-Mossbauer spectra has been undertaken in the quasi-ternary system La 0.8 Sr 0.2 (Mn,Fe,Co)O 3 . The spectra exhibit a wide variety from simple to complex line shapes due to varying magnetic and/or quadrupolar interactions. Most samples are non-magnetic and show a linear variation of isomer shift vs. formal oxidation state. Magnetism seems to depend on a critical amount of Fe 3+ –Fe 3+ interactions. A magnetic phase diagram of the system at room temperature is presented.

Extracellular vesicles (EVs) provide a complex means of intercellular signalling between cells at local and distant sites, both within and between different organs. According to their cell-type specific signatures, EVs can function as a novel class of biomarkers for a variety of diseases, and can be used as drug-delivery vehicles. Furthermore, EVs from certain cell types exert beneficial effects in regenerative medicine and for immune modulation. Several techniques are available to harvest EVs from various body fluids or cell culture supernatants. Classically, differential centrifugation, density gradient centrifugation, size-exclusion chromatography and immunocapturing-based methods are used to harvest EVs from EV-containing liquids. Owing to limitations in the scalability of any of these methods, we designed and optimised a polyethylene glycol (PEG)-based precipitation method to enrich EVs from cell culture supernatants. We demonstrate the reproducibility and scalability of this method and compared its efficacy with more classical EV-harvesting methods. We show that washing of the PEG pellet and the re-precipitation by ultracentrifugation remove a huge proportion of PEG co-precipitated molecules such as bovine serum albumine (BSA). However, supported by the results of the size exclusion chromatography, which revealed a higher purity in terms of particles per milligram protein of the obtained EV samples, PEG-prepared EV samples most likely still contain a certain percentage of other non-EV associated molecules. Since PEG-enriched EVs revealed the same therapeutic activity in an ischemic stroke model than corresponding cells, it is unlikely that such co-purified molecules negatively affect the functional properties of obtained EV samples. In summary, maybe not being the purification method of choice if molecular profiling of pure EV samples is intended, the optimised PEG protocol is a scalable and reproducible method, which can easily be adopted by laboratories equipped with an ultracentrifuge to enrich for functional active EVs. CA Giebel

The aim of our study was to modify the basis compound ss-TaON, which crystallizes in the monoclinic baddeleyite-type, by incorporation of appropriate dopant ions, in order to obtain anion-deficient cubic fluorite-type phases, which are of interest as solids with mobile nitrogen ions. For this purpose, scandium-doped tantalum oxide nitrides were prepared by ammonolysis of amorphous oxide precursors. An unexpected variety of phases with different structural features was observed: bixbyite-type phases of general composition Sc{sub x}Ta{sub 1-x}(O,N){sub y} with 0.33{

The efficient green phosphor Ba(3)Si(6)O(12)N(2):Eu(2+) and its solid-solution series Ba(3-x)Sr(x)Si(6)O(12)N(2) (with x approximately = 0.4 and 1) were synthesized in a radio-frequency furnace under nitrogen atmosphere at temperatures up to 1425 degrees C. The crystal structure (Ba(3)Si(6)O(12)N(2), space group P3 (no. 147), a = 7.5218(1), c = 6.4684(1) A, wR2 = 0.048, Z = 1) has been solved and refined on the basis of both single-crystal and powder X-ray diffraction data. Ba(3)Si(6)O(12)N(2):Eu(2+) is a layer-like oxonitridosilicate and consists of vertex-sharing SiO(3)N-tetrahedra forming 6er- and 4er-rings as fundamental building units (FBU). The nitrogen atoms are connected to three silicon atoms (N3), while the oxygen atoms are either terminally bound (O1) or bridge two silicon atoms (O2) (numbers in superscripted square brackets after atoms indicate the coordination number of the atom in question). Two crystallographically independent Ba(2+) sites are situated between the silicate layers. Luminescence investigations have shown that Ba(3)Si(6)O(12)N(2):Eu(2+) exhibits excellent luminescence properties (emission maximum at approximately 527 nm, full width at half maximum (FWHM) of approximately 65 nm, low thermal quenching), which provides potential for industrial application in phosphor-converted light-emitting diodes (pc-LEDs). In-situ high-pressure and high-temperature investigations with synchrotron X-ray diffraction indicate decomposition of Ba(3)Si(6)O(12)N(2) under these conditions. The band gap of Ba(3)Si(6)O(12)N(2):Eu(2+) was measured to be 7.05+/-0.25 eV by means of X-ray emission spectroscopy (XES) and X-ray absorption near edge spectroscopy (XANES). This agrees well with calculated band gap of 6.93 eV using the mBJ-GGA potential. Bonding to the Ba atoms is highly ionic with only the 4p(3/2) orbitals participating in covalent bonds. The valence band consists primarily of N and O p states and the conduction band contains primarily Ba d and f states with a small contribution from the N and O p states.

Within the ternary system Ga–O–N we performed experimental and theoretical investigations on the thermodynamics, structure and kinetics of new stable and metastable compounds. We studied the ammonolysis of β-Ga2O3 at elevated temperatures by means of ex situ X-ray diffraction, ex situ neutron diffraction, and in situ X-ray absorption spectroscopy (XAS). From total diffraction pattern refinement with the Rietveld method we analyzed the anionic occupancy factors and the lattice parameters of β-Ga2O3 during the reaction. Within the detection limits of these methods, we can rule out the existence of a crystalline oxynitride phase that is not derived from wurtzite-type GaN. The nitrogen solubility in β-Ga2O3 was found to be below the detection limit of about 2–3 at.% in the anionic sublattice. The kinetics of the ammonolysis of β-Ga2O3 to α-GaN and of the oxidation of α-GaN to β-Ga2O3 was studied by means of in situ X-ray absorption spectroscopy. In both cases the reaction kinetics could be described well by fitting linear combinations of β-Ga2O3 and α-GaN spectra only, excluding that other crystalline or amorphous phases appear during these reactions. The kinetics of the ammonolysis can be described well by an extended Johnson–Mehl–Avrami–Kolmogorow model with nucleation and growth of GaN nuclei, while the oxidation kinetics can be modeled by a shrinking core model where Ga2O3 grows as a layer. Investigations by means of TEM and SEM support the assumptions in both models. To investigate the structure and energetics of spinel-type gallium oxynitrides (γ-galons) we performed first-principles calculations using density-functional theory. In addition to the ideal cubic γ-Ga3O3N we studied gallium deficient γ-galons within the Constant-Anion-Model. In highly non-stoichiometric, amorphous gallium oxide of approximate composition GaO1.2 we found at a temperature around 670 K an insulator–metal transition, with a conductivity jump of seven orders of magnitude. We demonstrate through experimental studies and density-functional theory calculations that the conductivity jump takes place at a critical gallium concentration and is induced by crystallization of stoichiometric β-Ga2O3 within the metastable oxide matrix. By doping with nitrogen the critical temperature and the conductivity in the highly conducting state can be tuned.

In this contribution we review the impact of anionic and cationic substitutions on the electronic properties of bulk ZnO crystals, thin films and ZnO powders. p-type doping is discussed with focus on the anionic substitution of oxygen by nitrogen or phosphorous. n-type doping is exemplarily reviewed for substitution of Zn by group III elements. The impact of isoelectronic substitution of zinc (with Cd or Mg) or of oxygen (with S, Se, Te) on the band gap are also discussed for the respective ternary alloy. The substitution of Zn by the transition metal Mn introduces several electronic levels in the band gap which significantly alter the absorption and emission properties. Further, devices based on substitutional effects in ZnO are reviewed: Schottky diodes (unipolar device) and pn-diodes (bipolar device).

Human bone marrow-derived mesenchymal stem cells (MSC) home to injured tissues and have regenerative capacity. In this study, we have investigated in vitro the influence of apoptotic and necrotic cell death, thus distinct types of tissue damage, on MSC migration. Concordant with an increased overall motility, MSC migrated towards apoptotic, but not vital or necrotic neuronal and cardiac cells. Hepatocyte growth factor (HGF) was expressed by the apoptotic cells only. MSC, in contrast, revealed expression of the HGF-receptor, c-Met. Blocking HGF bioactivity resulted in significant reduction of MSC migration. Moreover, recombinant HGF attracted MSC in a dose-dependent manner. Thus, apoptosis initiates chemoattraction of MSC via the HGF/c-Met axis, thereby linking tissue damage to the recruitment of cells with regenerative potential.

The influence of molecular architecture on light-induced SRG formation was investigated. Polymers with different degree of branching were synthesized by ATRP and functionalized with azobenzene chromophores. The polymers differ only in their architecture - linear, 4-, 6-, or 12-arms stars. The photo-induced dichroism as well as the efficiency of SRG formation was similar for all polymers of this series. New consideration for the origin of the driving force was used to explain this behavior. The comparable SRG inscription rate in differently branched polymers can be rationalized by assuming that azobenzene acts as an internal molecular motor and can cause a non-turbulent motion on a scale smaller than that on which normal entanglement restriction forces act.

A pigment of your imagination: A range of polycrystalline solid solutions of a zinc-rich Zn(x-1)Mn(x)O system (see figure) have been prepared and studied in terms of their colour, diffuse reflectance spectra, Mn valence state and electronic structure. The intense optical absorption arises from Mn(2+) doping and is thought to be due to forbidden or partially forbidden transitions between the valence and the conduction band.We report an investigation of zinc-rich polycrystalline solid solutions of the Zn(1-x)Mn(x)O system concerning the colour, the diffuse reflectance spectra, the valence state of manganese and the electronic structure. Samples were prepared by a chemical-vapour-transport-assisted route and optimized with respect to colour strength. In agreement with previous experimental results, EPR studies showed that manganese is in the divalent charge state. The nature of the very intense optical absorption, which is caused by Mn(2+) doping and determines the colour of the material, is discussed. It is argued that the Mn(2+)-induced optical absorption is due to forbidden or partially forbidden transitions between the valence and the conduction band that involve Mn admixed states. This assignment is also confirmed by quantum chemical calculations using the semiempirical molecular orbital method MSINDO.