NGF Modulates Cholesterol Metabolism and Stimulates ApoE Secretion in Glial Cells Conferring Neuroprotection against Oxidative Stress

Cholesterol plays a crucial role in the brain, where its metabolism is particularly regulated by astrocytic activity. Indeed, adult neurons suppress their own cholesterol biosynthesis and import this sterol through ApoE-rich particles secreted from astrocytes. Recent evidence suggests that nerve growth factor (NGF) may exert neurotrophic activity by influencing cell metabolism. Nevertheless, the effect of NGF on glial cholesterol homeostasis has still not been elucidated. Thus, the aim of this project is to assess whether NGF could influence cholesterol metabolism in glial cells. To reach this objective, the U373 astrocyte-derived cell line was used as an experimental model. Immunoblot and ELISA analysis showed that proteins and enzymes belonging to the cholesterol metabolism network were increased upon NGF treatment in glial cells. Furthermore, NGF significantly increased ApoE secretion and the amount of extracellular cholesterol in the culture medium. Co-culture and U373-conditioned medium experiments demonstrated that NGF treatment efficiently counteracted rotenone-mediated cytotoxicity in N1E-115 neuronal cells. Conversely, neuroprotection mediated by NGF treatment was suppressed when N1E-115 were co-cultured with ApoE-silenced U373 cells. Taken together, these data suggest that NGF controls cholesterol homeostasis in glial cells. More importantly, NGF exerts neuroprotection against oxidative stress, which is likely associated with the induction of glial ApoE secretion.     

Thermoacoustic Emission from Carbon Nanotubes Imaged by Atomic Force Microscopy

The thermoacoustic effect of isolated single‐wall carbon nanotubes aligned between electrodes is experimentally observed for the first time by imaging the emitted acoustic wave using an atomic force microscopy‐based technique specifically developed for the task. The capability of such a technique for single‐point thermoacoustic measurements is first verified on carbon nanotubes layers with two electrodes for injecting alternate electric current. The technique is then demonstrated to allow the acquisition, simultaneously with the topography, of images reflecting the pressure of the acoustic wave at fixed distance from the sample. Such a capability is used to collect images reflecting the amplitude of acoustic waves generated by isolated nanotubes and nanotube bundles by the thermoacoustic effect.     

A Modular Composite Device of Poly(Ethylene Oxide)/Poly(Butylene Terephthalate) (PEOT/PBT) Nanofibers and Gelatin as a Dual Drug Delivery System for Local Therapy of Soft Tissue Tumors

In the clinical management of solid tumors, the possibility to successfully couple the regeneration of injured tissues with the elimination of residual tumor cells left after surgery could open doors to new therapeutic strategies. In this work, we present a composite hydrogel–electrospun nanofiber scaffold, showing a modular architecture for the delivery of two pharmaceutics with distinct release profiles, that is potentially suitable for local therapy and post-surgical treatment of solid soft tumors. The composite was obtained by coupling gelatin hydrogels to poly(ethylene oxide)/poly(butylene terephthalate) block copolymer nanofibers. Results of the scaffolds’ characterization, together with the analysis of gelatin and drug release kinetics, displayed the possibility to modulate the device architecture to control the release kinetics of the drugs, also providing evidence of their activity. In vitro analyses were also performed using a human epithelioid sarcoma cell line. Furthermore, publicly available expression datasets were interrogated. Confocal imaging showcased the nontoxicity of these devices in vitro. ELISA assays confirmed a modulation of IL-10 inflammation-related cytokine supporting the role of this device in tissue repair. In silico analysis confirmed the role of IL-10 in solid tumors including 262 patients affected by sarcoma as a negative prognostic marker for overall survival. In conclusion, the developed modular composite device may provide a key-enabling technology for the treatment of soft tissue sarcoma.     

Chiral Discrimination Mechanisms by Silylated-Acetylated Cyclodextrins: Superficial Interactions vs. Inclusion

Cyclodextrin derivatives constitute a powerful class of auxiliary agents for the discrimination of apolar chiral substrates. Both host–guest inclusion phenomena and interactions with the derivatizing groups located on the surface of the macrocycle could drive the enantiodiscrimination; thus, it is important to understand the role that these processes play in the rational design of new chiral selectors. The purpose of this study is to compare via nuclear magnetic resonance (NMR) spectroscopy the efficiency of silylated-acetylated α-, β-, and γ-cyclodextrins in the chiral discrimination of 1,1,1,3,3-pentafluoro-2-(fluoromethoxy)-3-methoxypropane (compound B) and methyl 2-chloropropionate (MCP). NMR DOSY (Diffusion Ordered SpectroscopY) experiments were conducted for the determination of the bound molar fractions and the association constants, whereas ROESY (Rotating-frame Overhauser Enhancement SpectroscopY) measurements provided information on the hosts’ conformation and on the interaction phenomena with the guests. Compound B, endowed with fluorinated moieties, is not deeply included due to attractive Si-F interactions occurring at the external surface of the cyclodextrins. Therefore, a low selectivity toward the size of cyclodextrin cavity is found. By contrast, enantiodiscrimination of MCP relies on the optimal fitting between the size of the guest and that of the cyclodextrin cavity.     

Blocking the Peroxisome Proliferator‐Activated Receptor (PPAR): An Overview

Peroxisome proliferator‐activated receptors (PPARs) have been studied extensively over the last few decades and have been assessed as molecular targets for the development of drugs against metabolic disorders. A rapid increase in understanding of the physiology and pharmacology of these receptors has occurred, together with the identification of novel chemical structures that are able to activate the various PPAR subtypes. More recent evidence suggests that moderate activation of these receptors could be favorable in pathological situations due to a decrease in the side effects brought about by PPAR agonists. PPAR partial agonists and antagonists are interesting tools that are currently used to better elucidate the biological processes modulated by this family of nuclear receptors. Herein we present an overview of the various molecular structures that are able to block each of the PPAR subtypes, with a focus on promising therapeutic applications.     

A Novel Function of the Triterpene Squalene in a Tritrophic System

Changes in apple leaf chemistry after infestation by leafminers and their effect on both host location and host habitat location of the generalist parasitoid Pholetesor bicolor were investigated. Chemical analysis of leaf solvent extracts from healthy and leafminer-damaged leaves revealed that herbivory increased the amount of the triterpene squalene (C₃₀H₅₀), whereas quantities of all other identified compounds were similar in both plant treatments. To assess the response of parasitoids to host location cues, contact bioassays were conducted with naïve females. Results showed that parasitoids performed a characteristic ovipositional probing more often on the mine-damaged than on the healthy leaf. This behavior was triggered by a hexane extract of the mine-damaged leaf, but not by a healthy leaf extract. A synthetic mixture of the compounds identified in the extract triggered a similar response. A mixture devoid of squalene was not active, whereas squalene alone elicited the probing behavior. To assess the use of the identified compounds in habitat location, Y-tube olfactometer experiments were conducted with naïve and experienced females. Results showed that squalene is not involved in habitat location and has no priming effect on P. bicolor. While other triterpenes are known to mediate habitat location of parasitoids, this is the first report in which a plant triterpene is shown to mediate host location of a parasitoid. The biological and ecological functions of squalene on all three trophic levels are discussed.     

NMR Profiling of Exhaled Breath Condensate Defines Different Metabolic Phenotypes of Non-Cystic Fibrosis Bronchiectasis

Nuclear-magnetic-resonance (NMR) profiling of exhaled breath condensate (EBC) provides insights into the pathophysiology of bronchiectasis by identifying specific biomarkers. We evaluated whether NMR-based metabolomics discriminates the EBC-derived metabolic phenotypes (“metabotypes”) of 41 patients with non-cystic fibrosis (nCF) bronchiectasis of various etiology [24 subjects with Primary Ciliary Dyskinesia (PCD); 17 patients with bronchiectasis not associated with PCD (nCF/nPCD)], who were compared to 17 healthy subjects (HS). NMR was used for EBC profiling, and Orthogonal Projections to Latent Structures with partial least-squares discriminant analysis (OPLS-DA) was used as a classifier. The results were validated by using the EBC from 17 PCD patients not included in the primary analysis. Different statistical models were built, which compared nCF/nPCD and HS, PCD and HS, all classes (nCF/nPCD-PCD-HS), and, finally, PCD and nCF/nPCD. In the PCD-nCF/nPCD model, four statistically significant metabolites were able to discriminate between the two groups, with only a minor reduction of the quality parameters. In particular, for nCF/nPCD, acetone/acetoin and methanol increased by 21% and 18%, respectively. In PCD patients, ethanol and lactate increased by 25% and 28%, respectively. They are all related to lung inflammation as methanol is found in the exhaled breath of lung cancer patients, acetone/acetoin produce toxic ROS that damage lung tissue in CF, and lactate is observed in acute inflammation. Interestingly, a high concentration of ethanol hampers cilia beating and can be associated with the genetic defect of PCD. Model validation with 17 PCD samples not included in the primary analysis correctly predicted all samples. Our results indicate that NMR of EBC discriminates nCF/nPCD and PCD bronchiectasis patients from HS, and patients with nCF/nPCD from those with PCD. The metabolites responsible for between-group separation identified specific metabotypes, which characterize bronchiectasis of a different etiology.     

Nanodiamond-mediated crystallization in fibers of PANI nanocomposites produced by template-free polymerization: Conductive and thermal properties of the fibrillar networks

The detonation nanodiamond is a novel versatile nanomaterial with tunable properties and surface chemistry. In this work, we report on a template-free method to synthesize polyaniline based nanocomposite fibers during a chemical oxidative precipitation polymerization where the cooperative interactions between nanodiamond and polyaniline nucleates trigger the final morphology of the nanocomposite. FE–SEM and TEM observations evidence the prominent growth of fibril-like structures assembled in 2-D networks of tightly woven, partially oriented fibers. Optical and Raman spectroscopy and X-ray diffraction analyses reveal that the polymer chains are in a protonated emeraldine form and organize themselves in a highly ordered 3-D spatial arrangement. Conductivity measurements performed on isolated fibers by a conductive tip of an AFM apparatus highlight that the diamond filler does not affect the conductive properties of the polyaniline matrix while increases the thermal stability of the polymer as confirmed by TGA studies.     

How We Make DNA Origami

DNA origami has attracted substantial attention since its invention ten years ago, due to the seemingly infinite possibilities that it affords for creating customized nanoscale objects. Although the basic concept of DNA origami is easy to understand, using custom DNA origami in practical applications requires detailed know‐how for designing and producing the particles with sufficient quality and for preparing them at appropriate concentrations with the necessary degree of purity in custom environments. Such know‐how is not readily available for newcomers to the field, thus slowing down the rate at which new applications outside the field of DNA nanotechnology may emerge. To foster faster progress, we share in this article the experience in making and preparing DNA origami that we have accumulated over recent years. We discuss design solutions for creating advanced structural motifs including corners and various types of hinges that expand the design space for the more rigid multilayer DNA origami and provide guidelines for preventing undesired aggregation and on how to induce specific oligomerization of multiple DNA origami building blocks. In addition, we provide detailed protocols and discuss the expected results for five key methods that allow efficient and damage‐free preparation of DNA origami. These methods are agarose‐gel purification, filtration through molecular cut‐off membranes, PEG precipitation, size‐exclusion chromatography, and ultracentrifugation‐based sedimentation. The guide for creating advanced design motifs and the detailed protocols with their experimental characterization that we describe here should lower the barrier for researchers to accomplish the full DNA origami production workflow.