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AbstractLimiting animal experiments is essential for ethical issues and also because scientific evidence highlights the discrepancies between human and animal metabolism. This review aims to provide a critical discussion of the strengths and limitations of the most appropriate in vitro intestine model to answer complex research questions in pharmaceutical and nutraceutical fields. This review describes the components contributing to the definition of the gut barrier structure, from the outer mucus layer to the inner part of lamina propria, including endothelial and neuronal networks. We conclude that the main advantage of these co-culture models is their versatility since they are modulable systems in which each component can be added, changed, or removed to reproduce a specific physiological condition each time. Additionally, we compare intestinal organoid models and microfluidic systems with well-established co-culture models. [ABSTRACT FROM AUTHOR]

A novel starch-based ether bearing cinnamyl functionalities, conferring photo-crosslinking properties, is synthesised by reaction with cinnamyl chloride in the presence of sodium hydroxide. Natural yuca was selected as a sustainable source of starch. Three different molar equivalents of reagents are used, affording starch-cinnamyl ethers with different degrees of substitution, ranging from 0.09 to 1.24, as determined by liquid phase nuclear magnetic resonance (NMR). The double bonds in the cinnamyl moieties show reactivity towards photodimerization upon irradiation at 254 nm, affording a novel cross-linked bio-inspired polymer. The formation of the covalent ether linkage and the [2+2] cycloaddition of the cinnamyl units are confirmed by a combination of spectroscopic techniques, including solid state NMR. The materials are further characterized by gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). Starch-cinnamyl ethers with a DS of 0.09 are water soluble, and suitable for the preparation of transparent films potentially exploitable for biodegradable packaging materials. [ABSTRACT FROM AUTHOR]

To improve wound healing, advanced biofabrication techniques are proposed here to develop customized wound patches to release bioactive agents targeting cell function in a controlled manner. Three-dimensional (3D) bioprinted "smart" patches, based on methacrylated gellan gum (GGMA), loaded with tannic acid (TA) or L-ascorbic acid (AA) have been manufactured. To improve stability and degradation time, gellan gum (GG) was chemically modified by grafting methacrylic moieties on the polysaccharide backbone. GGMA patches were characterized through physicochemical, morphological and mechanical evaluation. Kinetics release and antioxidant potential of TA and AA as well as antimicrobial activity against common pathogens Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli in accordance with ISO 22196:2011 are reported. The cytocompatibility of the patches was demonstrated by direct and indirect tests on human dermal fibroblasts (HDF) as per ISO 10993. The positive effect of GGMA patches on cell migration was assessed through a wound healing assay. The results highlighted that the patches are cytocompatible, speed up wound healing and can swell upon contact with the hydration medium and release TA and AA in a controlled way. Overall, the TA- and AA-loaded GGMA patches demonstrated suitable mechanical features; no cytotoxicity; and antioxidant, antimicrobial and wound healing properties, showing satisfactory potential for wound dressing applications. [ABSTRACT FROM AUTHOR]

Due to the increasing demand of cooling systems, new techniques to produce materials with specific optical properties are being developed for innovative applications such as passive daytime radiative cooling (PDRC). In recent years, electrospun polymeric coatings have been proposed as one of the most promising and scalable techniques for PDRC, due to the high solar reflectivity induced by their nanofibrous structure. Specifically, electrospun poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) exhibit negligible absorption in the solar wavelength range, and a selective emissivity in the atmospheric transparency range provided by its C-F bonds. However, the production of these coatings by electrospinning involves the use of toxic or hazardous solvents. In this study, we explore the substitution of traditional solvents with a non-toxic one, i.e., dimethyl sulfoxide (DMSO), to produce PVDF-HFP electrospun coatings. Through an easy one-step electrospinning process, 35 μm-thick coatings composed of well-defined, cylindrical, uniform, and continuous fibers are obtained with comparable properties to those obtained using traditional solvents.

Bio-derived monomers and biobased building blocks obtained from natural sources, e.g., fats and oils, are attracting increasing attention mainly due to sustainability concerns. Due to their features, renewable feedstocks are an excellent alternative to petroleum-based raw materials to shift towards greener chemistry, especially when coupled with energy-efficient processes like photopolymerization. In this review, we illustrate the recent research outcomes in the field of photocurable biobased monomers, showing the advantages of using biobased chemicals for the synthesis of photocurable monomers and the potential of naturally derived building blocks in photocuring reactions. [ABSTRACT FROM AUTHOR]

Simple Summary: Numerous findings demonstrate that the central nervous system and the peripheral organs and tissues communicate in physiological and pathological conditions thanks to the exchange of signaling molecules transported via blood, cerebrospinal fluid, and lymph. Extracellular vesicles, which can cross tissue barriers, including the blood–brain barrier, play a key role in this bidirectional communication by safely delivering these molecules, including proteins, lipids, and nucleic acids such as microRNAs (miRNAs). In particular, the latter involved in the post-transcriptional regulation of gene expression can alter recipient cells' functions and orchestrate their behavior in response to different biological events. Thus, elucidating the role played by EVs-delivered miRNAs in brain–periphery communication could offer valuable insights for advancing the treatment and management of neurological and systemic diseases. Bidirectional communication between the central nervous system (CNS) and peripheral organs and tissue has been widely documented in physiological and pathological conditions. This communication relies on the bilateral transmission of signaling molecules and substances that circulate throughout the body and reach their target site(s) via the blood and other biological fluids (e.g., the cerebrospinal fluid, the lymph). One of the mechanisms by which these molecular messengers are exchanged is through the secretion of extracellular vesicles (EVs). EVs are known to mediate cell-to-cell communication by delivering biological molecules, including nucleic acids, proteins, lipids, and various other bioactive regulators. Moreover, EVs can cross the blood–brain barrier (BBB), enabling direct communication between the periphery and the brain. In particular, the delivery of microRNAs (miRNAs) can modulate the expression profiles of recipient cells, thereby influencing their functions. This review synthesizes current findings about the brain–periphery cross-talk mediated by EVs-delivered miRNAs. Although this mechanism has been definitively shown in a few cases, much evidence indirectly indicates that it could mediate brain–peripherical organs/tissue communication, especially in pathological conditions. Therefore, understanding this process could provide valuable insights for the treatment and management of neurological and systemic diseases. [ABSTRACT FROM AUTHOR]

This study aims at the modification of the surface properties of twill-5 polyethylene terephthalate (PET) fabric, in particular to improve its hydrophilicity. It compares the hydrophilic potential and efficacy of two vinyl monomers radically grafted onto the fabric by photoinduced processes. Poly(ethylene glycol) diacrylate (PEGDA) and [2-(methacryloyloxy)-ethyl]-trimethylammonium chloride (METAC) affected the wettability of the fabric towards water, significantly reducing the water contact angle (WCA). As a consequence, the treated fabrics showed a good improvement of dynamic moisture management. Adopting specific conditions (e.g., type of monomer and grafting monomer concentration), the grafted PET fabrics remained hydrophilic after washing, laudering, dry cleaning, and rubbing tests; thus, the surface treatment modification resulted to be durable overall. [ABSTRACT FROM AUTHOR]

Electrolytes consisting of low molecular weight perfluoropolyether (PFPE), poly(ethylene glycol) (PEG), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) blends were prepared and systematically studied for salt concentration and stoichiometry effects on the materials" thermal and electrochemical properties. Herein we report that the tunable ratios of PFPE and PEG allow for precise control of crystalline melting and glass transition temperature properties. These blended liquid polymer electrolytes are inherently nonflammable and remain stable in the amorphous phase from approximately 150 °C down to -85 °C. The ionic conductivity of the electrolytes are on the order of 10-4 S/cm at 30 °C, which makes them suitable for rechargeable lithium batteries.

Author(s): Anatol Luther [sup.1] , Matthias Urfer [sup.2] , Michael Zahn [sup.3] , Maik Müller [sup.4] , Shuang-Yan Wang [sup.2] , Milon Mondal [sup.2] , Alessandra Vitale [sup.5] , Jean-Baptiste [...], There is an urgent need for new antibiotics against Gram-negative pathogens that are resistant to carbapenem and third-generation cephalosporins, against which antibiotics of last resort have lost most of their efficacy. Here we describe a class of synthetic antibiotics inspired by scaffolds derived from natural products. These chimeric antibiotics contain a [beta]-hairpin peptide macrocycle linked to the macrocycle found in the polymyxin and colistin family of natural products. They are bactericidal and have a mechanism of action that involves binding to both lipopolysaccharide and the main component (BamA) of the [beta]-barrel folding complex (BAM) that is required for the folding and insertion of [beta]-barrel proteins into the outer membrane of Gram-negative bacteria. Extensively optimized derivatives show potent activity against multidrug-resistant pathogens, including all of the Gram-negative members of the ESKAPE pathogens.sup.1. These derivatives also show favourable drug properties and overcome colistin resistance, both in vitro and in vivo. The lead candidate is currently in preclinical toxicology studies that--if successful--will allow progress into clinical studies that have the potential to address life-threatening infections by the Gram-negative pathogens, and thus to resolve a considerable unmet medical need. A class of chimeric synthetic antibiotics that bind to lipopolysaccharide and BamA shows potent activity against multidrug-resistant Gram-negative bacteria, with the potential to address life-threatening infections.

Simple Summary: COVID-19, with persistent and new onset of symptoms, such as fatigue, post-exertional malaise, and cognitive dysfunction that impact everyday functioning, is referred to as long-COVID under the general category of post-acute sequelae of the SARS-CoV-2 infection (PASC). It includes a wide range of signs and symptoms that can last weeks, months, or even years after infection, most of which are attributable to dysfunctions of the neurovegetative system. The causative mechanisms are still unknown, but autoimmunity and the production of autoantibodies targeting self-antigens via the molecular mimicry phenomenon seem to have a role. Here we evaluated the presence of autoantibodies against two proteins of vagal nuclei sharing a peptide with SARS-CoV-2 spike glycoprotein in sera from ongoing symptomatic COVID-19 patients (long-COVID) with cardiorespiratory symptoms, subjects vaccinated without a history of SARS-CoV-2 infection, and subjects not vaccinated without a history of SARS-CoV-2. Putative autoantibodies are present in both long-COVID-19 and vaccinated groups, suggesting that both viral infection and vaccination may trigger autoreactivity. However, the presence of autoantibodies is not sufficient for triggering autoimmunity, and other predisposing conditions must co-occur. Therefore, it is necessary to run further investigations to clarify the complex mechanisms involved in the development of long-COVID, providing knowledge which may offer further information for the prevention and treatment of the disease. As reported by the World Health Organization (WHO), about 10–20% of people have experienced mid- to long-term effects following SARS-CoV-2 infection, collectively referred to as post-COVID-19 condition or long-COVID, including some neurovegetative symptoms. Numerous findings have suggested that the onset of these neurovegetative symptoms upon viral infection may be caused by the production of autoantibodies through molecular mimicry phenomena. Accordingly, we had previously demonstrated that 22 of the human proteins sharing putatively immunogenic peptides with SARS-CoV-2 proteins are expressed in the dorsal motor nucleus and nucleus ambiguous. Therefore, if molecular mimicry occurs following severe forms of COVID-19, there could be transitory or permanent damage in some vagal structures, resulting in a lower vagal tone and all the related clinical signs. We investigated the presence of autoantibodies against two proteins of vagal nuclei sharing a peptide with SARS-CoV-2 spike glycoprotein using an immunoassay test on blood obtained from patients with cardiorespiratory symptoms in patients affected by ongoing symptomatic COVID-19 (long-COVID), subjects vaccinated without a history of SARS-CoV-2 infection, and subjects not vaccinated without a history of SARS-CoV-2 infection. Interestingly, putative autoantibodies were present in both long-COVID-19 and vaccinated groups, opening interesting questions about pathogenic mechanisms of the disease. [ABSTRACT FROM AUTHOR]