45 research outputs found

    Reasons for success and lessons learnt from nanoscale vaccines against COVID-19.

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    From PubMed via Jisc Publications RouterPublication status: ppublis

    Reasons for success and lessons learnt from nanoscale vaccines against COVID-19

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    Almost all currently used vaccines against COVID-19 consist of either non-viral or viral nanoparticles. Here we attempt to understand the reasons behind the success of such advanced nanoscale vaccine technologies compared with clinically established conventional vaccines, and the lessons to be learnt from this potentially transformative development in the adoption and acceptance of nanotechnology for medicine.T.K. and K.K. acknowledge financial support from the UK Research & Innovation Engineering and Physical Sciences Research Council International Centre-to-Centre grant (EP/S030719/1). A.Y. thanks the Scientific and Technological Research Council of Turkey (TUBITAK, 18AG020) and the Turkish Academy of Sciences (TUBA, GEBP 2018) for financial support

    Transient reprogramming of postnatal cardiomyocytes to a dedifferentiated state

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    In contrast to mammals, lower vertebrates are capable of extraordinary myocardial regeneration thanks to the ability of their cardiomyocytes to undergo transient dedifferentiation and proliferation. Somatic cells can be temporarily reprogrammed to a proliferative, dedifferentiated state through forced expression of Oct3/4, Sox2, Klf4 and c-Myc (OSKM). Here, we aimed to induce transient reprogramming of mammalian cardiomyocytes in vitro utilising an OSKM-encoding non-integrating vector. Reprogramming factor expression in postnatal rat and mouse cardiomyocytes triggered rapid but limited cell dedifferentiation. Concomitantly, a significant increase in cell viability, cell cycle related gene expression and Ki67 positive cells was observed consistent with an enhanced cell cycle activation. The transient nature of this partial reprogramming was confirmed as cardiomyocyte-specific cell morphology, gene expression and contractile activity were spontaneously recovered by day 15 after viral transduction. This study provides the first evidence that adenoviral OSKM delivery can induce partial reprogramming of postnatal cardiomyocytes. Therefore, adenoviral mediated transient reprogramming could be a novel and feasible strategy to recapitulate the regenerative mechanisms of lower vertebrates

    Engineering of a graphene oxide-based two-dimensional platform for immune activation and modulation

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    Nanoscale-based tools for immunomodulation are expected to offer a rich battery of options for more targeted and safer approaches to achieve clinically effective manipulation of the local and systemic immune environment. In this study, we aimed to design nanoscale constructs based on graphene oxide (GO) nanosheets as platform carriers for the TLR7/8 agonist Resiquimod (R848). The non-covalent complexation of R848 molecules on the GO surface resulted in stable complexes by preserving their biological activity. The physicochemical properties, molecular quantification, as well as the overall performance of the complex were systematically investigated. We hypothesized the formation of GO:drug nano-constructs with strong colloidal stability over time, due to the strong π-π interactions between the R848 molecules and the GO surface, and identified that R848 loading efficiency consistently ranged around 75% (of starting molecules), quantified by HPLC and UV-Vis. The 2D morphology of the thin nanosheets was retained after complexation, determined by various (AFM and SEM) microscopic techniques. Based on the surface physicochemical characterization of the complexes by Raman, FTIR, XPS, and XRD, the formation of non-covalent interactions among the GO surface and the R848 molecules was confirmed. Most importantly, GO:R848 complexes did not compromise the biological activity of R848, and effectively activated macrophages in vitro. Collectively, this study demonstrates that thin GO sheets can act as platforms for the non-covalent association with small TLR7/8 agonist molecules, forming stable and highly reproducible complexes, that could be exploited as effective immunomodulatory agents

    Adenoviral Mediated Delivery of OSKM Factors Induces Partial Reprogramming of Mouse Cardiac Cells In Vivo

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    The induction of in vivo reprogramming toward pluripotency has been demonstrated in several tissues utilizing either transgenic inducible mice or gene delivery approaches. However, the effects of exogenous reprogramming factor expression in the mammalian heart have not been previously reported. The present study aims to investigate the response of cardiac cells to ectopic Oct3/4, Sox2, Klf4, and cMyc (OSKM) expression in vivo using a non-integrating adenoviral vector. Direct intramyocardial injection of this vector achieves effective and transient OSKM overexpression in the healthy heart and after myocardial infarction. The expression of these factors induces transient upregulation of a number of endogenous pluripotency (endo-Oct3/4, Gdf3) and reprogramming related (Cdh1, Fut4) genes, confirming the induction of cell reprogramming. Despite the initiation of reprogramming, markers of fully de-differentiated cells including Nanog remain silenced, consistent with a partially reprogrammed state. Furthermore, no indications of tumorigenesis or teratoma formation are observed. Overall, these data suggest that adenoviral mediated OSKM delivery can be utilized to induce partial in vivo reprogramming. However, the absence of any clear regenerative effects after myocardial infarction indicates that further optimization of vector mediated reprogramming strategies is essential to overcome barriers to therapeutic efficacy

    Behavioral and Cognitive Performance Following Exposure to Second-Hand Smoke (SHS) from Tobacco Products Associated with Oxidative-Stress-Induced DNA Damage and Repair and Disruption of the Gut Microbiome

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    Exposure to second-hand Smoke (SHS) remains prevalent. The underlying mechanisms of how SHS affects the brain require elucidation. We tested the hypothesis that SHS inhalation drives changes in the gut microbiome, impacting behavioral and cognitive performance as well as neuropathology in two-month-old wild-type (WT) mice and mice expressing wild-type human tau, a genetic model pertinent to Alzheimer’s disease mice, following chronic SHS exposure (10 months to ~30 mg/m3). SHS exposure impacted the composition of the gut microbiome as well as the biodiversity and evenness of the gut microbiome in a sex-dependent fashion. This variation in the composition and biodiversity of the gut microbiome is also associated with several measures of cognitive performance. These results support the hypothesis that the gut microbiome contributes to the effect of SHS exposure on cognition. The percentage of 8-OHdG-labeled cells in the CA1 region of the hippocampus was also associated with performance in the novel object recognition test, consistent with urine and serum levels of 8-OHdG serving as a biomarker of cognitive performance in humans. We also assessed the effects of SHS on the percentage of p21-labeled cells, an early cellular marker of senescence that is upregulated in bronchial cells after exposure to cigarette smoke. Nuclear staining of p21-labeled cells was more prominent in larger cells of the prefrontal cortex and CA1 hippocampal neurons of SHS-exposed mice than in sham-exposed mice, and there was a significantly greater percentage of labelled cells in the prefrontal cortex and CA1 region of the hippocampus of SHS than air-exposed mice, suggesting that exposure to SHS may result in accelerated brain aging through oxidative-stress-induced injury

    Graphene Oxide Nanoscale Platform Enhances the Anti-Cancer Properties of Bortezomib in Glioblastoma Models

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    Graphene-based 2D nanomaterials possess unique physicochemical characteristics which can be utilized in various biomedical applications, including the transport and presentation of chemotherapeutic agents. In glioblastoma multiforme (GBM), intratumorally administered thin graphene oxide (GO) nanosheets demonstrate a widespread distribution throughout the tumor volume without impact on tumor growth, nor spread into normal brain tissue. Such intratumoral localization and distribution can offer multiple opportunities for treatment and modulation of the GBM microenvironment. Here, the kinetics of GO nanosheet distribution in orthotopic GBM mouse models is described and a novel nano-chemotherapeutic approach utilizing thin GO sheets as platforms to non-covalently complex a proteasome inhibitor, bortezomib (BTZ), is rationally designed. Through the characterization of the GO:BTZ complexes, a high loading capacity of the small molecule on the GO surface with sustained BTZ biological activity in vitro is demonstrated. In vivo, a single low-volume intratumoral administration of GO:BTZ complex shows an enhanced cytotoxic effect compared to free drug in two orthotopic GBM mouse models. This study provides evidence of the potential that thin and small GO sheets hold as flat nanoscale platforms for GBM treatment by increasing the bioavailable drug concentration locally, leading to an enhanced therapeutic effect
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