312 research outputs found

    New physical and chemical approaches for the cytosolic delivery of bio- therapeutics and nanoparticles into cells

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    Delivery of bio-therapeutics and nanomaterials into living cells is an important step not only for cell studies but also for therapy and bio-imaging. Clear examples are the intracellular delivery of various classes of nucleic acids (siRNA, µRNA, mRNA, pDNA), peptides and proteins for therapy purposes. As another example, all types of (inorganic/organic) nanoparticles are under investigation as intracellular labels for imaging purposes. Meanwhile it generally accepted that after uptake by cells, nanomaterials typically end up in endo-lysosomal vesicles in which they remain entrapped while they should escape from such compartments and arrive in the cytosolic fluids of the cells. In recent years our team undertook major efforts to understand the biophysics which play a role in (a lack of) escape of nanomaterials from endo-lysosomal vesicles. Vere recently we also discovered new chemical strategies (so named ‘escape adjuvants’) (1) which seems promising to ‘liberate’ nucleic acids (like siRNA) from endo-lysosomal vesicles into the cytosol. Furthermore we explored physical methods (either light (2,3) or ultrasound (4) driven) which directly deliver bio-therapeutics into the cytosol, thereby bypassing the endo-lysosomal routes. This lecture will explain our recent findings in this area, as reported in a serious of recently published papers (1-4). Both pharmaceutical, biological and engineering aspects of our work will be highlighted in the lecture. References 1) Repurposing cationic amphiphilic drugs as adjuvants to induce lysosomal siRNA escape in nanogel transfected cells F. Joris, L. De Backer, T. Van de Vyver, C. Bastiancich, S.C. De Smedt, K. Raemdonck Journal of Controlled Release 2018, in Press 2) Comparison of gold nanoparticle mediated photoporation: vapour nanobubbles outperform direct heating for delivering macromolecules in live cells R.H. Xiong, K. Raemdonck, K. Peynshaert, I. Lentacker, I. De Cock, J. Demeester, S.C. De Smedt, A.G. Skirtach, K. Braeckmans ACS Nano 2014, 8(6): 6288-6296 3) Cytosolic Delivery of Nanolabels Prevents Their Asymmetric Inhentance and Enables Extended Quantitative in Vivo Cell Imaging R.H. Xiong, F. Joris, S.Y. Liang, R. De Rycke, S. Lippens, J. Demeester, A. Skirtach, K. Raemdonck, U. Himmelreich, S.C. De Smedt, K. Braeckmans Nano Letters 2016, 16(10): 5975-5986 4) Sonoprinting and the importance of microbubble loading for the ultrasound mediated cellular delivery of nanoparticles I. De Cock, G.P.R. Lajoinie, M. Versluis, S.C. De Smedt*, I. Lentacker Biomaterials 2016, 83: 294-30

    PF4 (platelet factor 4)

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    Review on PF4, with data on DNA/RNA, on the protein encoded and where the gene is implicated

    PF4V1 (Platelet Factor 4 Variant 1)

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    Review on PF4V1 (Platelet Factor 4 Variant 1), with data on DNA, on the protein encoded, and where the gene is implicated

    Needle lost in the haystack: multiple reaction monitoring fails to detect Treponema pallidum candidate protein biomarkers in plasma and urine samples from individuals with syphilis [version 2; referees: 2 approved]

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    Background: Current syphilis diagnostic strategies are lacking a sensitive manner of directly detecting Treponema pallidum antigens. A diagnostic test that could directly detect T. pallidum antigens in individuals with syphilis would be of considerable clinical utility, especially for the diagnosis of reinfections and for post-treatment serological follow-up. Methods: In this study, 11 candidate T. pallidum biomarker proteins were chosen according to their physiochemical characteristics, T. pallidum specificity and predicted abundance. Thirty isotopically labelled proteotypic surrogate peptides (hPTPs) were synthesized and incorporated into a scheduled multiple reaction monitoring assay. Protein extracts from undepleted/unenriched plasma (N = 18) and urine (N = 4) samples from 18 individuals with syphilis in various clinical stages were tryptically digested, spiked with the hPTP mixture and analysed with a triple quadruple mass spectrometer. Results: No endogenous PTPs corresponding to the eleven candidate biomarkers were detected in any samples analysed. To estimate the Limit of Detection (LOD) of a comparably sensitive mass spectrometer (LTQ-Orbitrap), two dilution series of rabbit cultured purified T. pallidum were prepared in PBS. Polyclonal anti-T. pallidum antibodies coupled to magnetic Dynabeads were used to enrich one sample series; no LOD improvement was found compared to the unenriched series. The estimated LOD of MS instruments is 300 T. pallidum/ml in PBS. Conclusions: Biomarker protein detection likely failed due to the low (femtomoles/liter) predicted concentration of T. pallidum proteins. Alternative sample preparation strategies may improve the detectability of T. pallidum proteins in biofluids

    The pleural mesothelium and TGF-β1 pathways in restrictive allograft syndrome : a pre-clinical investigation

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    BACKGROUND: Chronic lung allograft dysfunction (CLAD) hampers long-term survival after lung transplantation. Common fibrosis-related mechanisms in idiopathic pulmonary fibrosis and CLAD instigated the consideration of investigating the differential regulation of pleural mesothelium and transforming growth factor-beta(1) (TGF-beta(1)) in restrictive allograft syndrome (RAS). METHODS: TGF-beta(1) was assessed in bronchoalveolar lavage (BAL) fluid using enzyme-linked immunoassay and via immune staining of explant biopsies. To assess the role of the pleura, explanted bronchiolitis obliterans syndrome (BOS) and RAS lungs were compared using computed tomography scans, calretinin stainings, Western blot, and quantititative real-time PCR. Last, a pleural mesothelial cell line was used to assess mesothelial-to-mesenchymal transition and its inhibition. RESULTS: TGF-beta(1) was increased in BAL of RAS patients (p = 0.035), and was present in the (sub) pleural area of biopsies. Explanted RAS lungs demonstrated an increased volume fraction of pleura (p = 0.0004), a higher proportion of calretinin-positive stainings (p = 0.0032), and decreased E-cadherin (p = 0.019) and increased alpha-smooth muscle actin (p = 0.0089) mRNA expression and protein levels in isolated pleural tissue. Moreover, TGF-beta(1) stimulation of pleural mesothelial cells led to a phenotypical switch to mesenchymal cells, accompanied with an increased migratory capacity. Interleukin-1 alpha was able to accentuate TGF-beta(1). induced mesothelial-to-mesenchymal transition. None of the tested drugs could inhibit mesothelial-to-mesenchymal transition at the used concentrations. CONCLUSIONS: Our results support an interplay between TGF-beta(1) and the pleural mesothelium in the pathophysiology of RAS. (C) 2019 International Society for Heart and Lung Transplantation. All rights reserved

    The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer

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    Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al

    Correction to:Expanding controlled donation after the circulatory determination of death: statement from an international collaborative (Intensive Care Medicine, (2021), 47, 3, (265-281), 10.1007/s00134-020-06341-7)

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    The article “Expanding controlled donation after the circulatory determination of death: statement from an international collaborative”, written by Domínguez-Gil, B., Ascher, N., Capron, A.M. et al. was originally published electronically on the publisher’s internet portal on 21 February 2021 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 25 March 2021 to © The Author(s) 2021 and the article is forthwith distributed under a Creative Commons Attribution this article is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, which permits any non-commercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc/4.0/. The original article has been corrected
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