Exploiting Extracellular Vesicles Strategies to Modulate Cell Death and Inflammation in COVID-19

The coronavirus disease (COVID-19) is responsible for more than 5 million deaths worldwide, with respiratory failure being the most common clinical presentation. COVID-19 complications still present a considerable burden on healthcare systems, and signs of the post-COVID syndrome are concerns for potential long-term damages. An increasing body of evidence highlights extracellular vesicles' (EVs) relevance in modulating inflammation and cell death in the diseases related to these processes. Several types of EVs-based investigational new drugs against COVID-19 have been approved by the US Food and Drug Administration to initiate a Phase I/II trial under an Investigational New Drug protocol. EVs can be employed as natural drug delivery nanoparticle-based systems due to their inherent potential in transferring material between cells, their natural origin, and their capability to encapsulate various biological molecules, offering an exciting alternative for administering drugs acting on the cell cycle control. In this context, small-molecule inhibitors of Mouse Double Minute 2 (MDM2) such as Nutlin-3 and Idasanutlin by promoting p53 survival and its antiviral activity might be helpful to modulate the IFN signalling pathway and reduce the overall pro-inflammatory burden

Imaging and therapy of ovarian cancer: Clinical application of nanoparticles and future perspectives

Despite significant advances in cancer diagnostics and treatment, ovarian cancers (OC) continue to kill more than 150,000 women every year worldwide. Due to the relatively asymptomatic nature and the advanced stage of the disease at the time of diagnosis, OC is the most lethal gynecologic malignancy. The current treatment for advanced OC relies on the synergistic effect of combining surgical cytoreduction and chemotherapy; however, beside the fact that chemotherapy resistance is a major challenge in OC management, new imaging strategies are needed to target microscopic lesions and improve both cytoreductive surgery and patient outcomes. In this context, nanostructured probes are emerging as a new class of medical tool that can simultaneously provide imaging contrast, target tumor cells, and carry a wide range of medicines resulting in better diagnosis and therapeutic precision. Herein we summarize several exemplary efforts in nanomedicine for addressing unmet clinical needs

The proline-rich peptide Bac7(1-35) reduces mortality from Salmonella typhimurium in a mouse model of infection

<p>Abstract</p> <p>Background</p> <p>Bac7 is a proline-rich peptide with a potent <it>in vitro </it>antimicrobial activity against Gram-negative bacteria. Here we investigated its activity in biological fluids and <it>in vivo </it>using a mouse model of <it>S. typhimurium </it>infection.</p> <p>Results</p> <p>The efficacy of the active 1-35 fragment of Bac7 was assayed in serum and plasma, and its stability in biological fluids analyzed by Western blot and mass spectrometry. The ability of the peptide to protect mice against <it>Salmonella </it>was assayed in a typhoid fever model of infection by determination of survival rates and bacterial load in liver and spleen of infected animals. In addition, the peptide's biodistribution was evaluated by using time-domain optical imaging. Bac7(1-35) retained a substantial <it>in vivo </it>activity showing a very low toxicity. The peptide increased significantly the number of survivors and the mean survival times of treated mice reducing the bacterial load in their organs despite its rapid clearance.</p> <p>Conclusions</p> <p>Our results provide a first indication for a potential development of Bac7-based drugs in the treatment of salmonellosis and, eventually, other Gram-negative infections. The <it>in vivo </it>activity for this peptide might be substantially enhanced by decreasing its excretion rate or modifying the treatment schedule.</p

Meniscal ossicles as micro-CT imaging biomarker in a rodent model of antigen-induced arthritis: A synchrotron-based x-ray pilot study

It is increasingly recognized that early detection of bone erosion plays an important role in the overall evaluation of rheumatoid arthritis and in the choice of the correct treatment approach. Since an appropriate use of imaging biomarkers in preclinical settings offers the prospect of smaller and optimized sample size, in the present study we define an anatomical imaging biomarker that could be objectively measured from micro-CT imaging data as an indicator of bone erosion in arthritis process. The well-characterized antigen-induced arthritis (AIA) model in rats was used. The animals were divided into 2 groups: arthritic disease control and arthritic having been administrated with the tumor necrosis factor alpha-blocking agent (Humira). Rats were sacrificed in the acute phase of AIA; peripheral blood and synovial tissue were collected for assessment of arthritis. Ex vivo micro-CT tomography of knee joints was performed at the Elettra synchrotron light source (Trieste, Italy). Overall, results from this study suggest that use of high-resolution micro-CT analysis coupled with meniscal ossicles bone parameters quantification provide a powerful combination to enhance data interpretation and assessment of disease-modifying drugs in an animal model of arthritis

Quantitative Acylation of Amino Compounds Catalysed by Penicillin G Acylase in Organic Solvent at Controlled Water Activity

Covalently immobilised penicillin G acylase (PGA-450) accepts in toluene, at controlled water activity (aw), a broad range of amino compounds as nucleophiles in kinetically controlled acylation. Hydrolytic reactions were prevented and complete conversions were achieved in short times even when working with an equimolar concentration of the substrates. The recovery of the products was facile, leading to high isolation yields. The obtained N-acylated derivatives of L-amino acids can be used in further reactions, since no purification steps are required in such conditions. This opens new perspectives to the application of PGA in selective protection of the amino function for peptide synthesis. Ali attempts to perform esterification and transesterification reactions with PGA in toluene, at the same aw as used for the acylation of amino compounds, were unsuccesful

A new tool for investigation platelet activation in endometriosis patients

Objectives: Endometriosis (EM) is a gynecological disease characterized by chronic inflammation, due to the interaction of inflammatory cells with ectopic endometrium (1). Platelets (PLTs), recruited by procoagulant factors released from endometriotic stromal cells, secrete angiogenetic factors and induce overexpression of genes involved in pro-survival/ anti-apoptotic propensity, inflammationand extracellular matrix remodeling (2). We aimed to develop a tool to measure PLT activation (by small extracellular vesicles, s-EVs) in EM peritoneal fluids, as a potential predictive marker of EM severity. Materials & methods: S-EVs were isolated from EM peritoneal fluids and characterized with imaging (Atomic Force Microscopy; AFM) and protein expression analyses (Western blot, WB) (3). We explored gene expression in peritoneum and EM lesions using EndometDB (4). Results: We demonstrated the presence of s-EVs isolated from EM peritoneal fluids by liquid AFM, as showed by contact angle vs diameter scatterplot (Fig.1A-B), and by WB detecting the s-EV markers CD63, CD9, and TSG101 (Fig.1C). Using Endomet-DB, we highlighted the differentially expressed genes between control and EM peritoneum samples (Fig.1D). The protein expression of a panel of biomarkers of PTL in s-EVs was further confirmed by WB (Fig.1E). Conclusions: We propose applying s-EV research to EM investigation, generating a novel biochemical tool for PLT activation assessment and for the development of new diagnostics and therapies

A framework for the comparative assessment of neuronal spike sorting algorithms towards more accurate off-line and on-line microelectrode arrays data analysis

Neuronal spike sorting algorithms are designed to retrieve neuronal network activity on a single-cell level from extracellular multiunit recordings with Microelectrode Arrays (MEAs). In typical analysis of MEA data, one spike sorting algorithm is applied indiscriminately to all electrode signals. However, this approach neglects the dependency of algorithms' performances on the neuronal signals properties at each channel, which require data-centric methods. Moreover, sorting is commonly performed off-line, which is time and memory consuming and prevents researchers from having an immediate glance at ongoing experiments. The aim of this work is to provide a versatile framework to support the evaluation and comparison of different spike classification algorithms suitable for both off-line and on-line analysis. We incorporated different spike sorting "building blocks" into a Matlab-based software, including 4 feature extraction methods, 3 feature clustering methods, and 1 template matching classifier. The framework was validated by applying different algorithms on simulated and real signals from neuronal cultures coupled to MEAs. Moreover, the system has been proven effective in running on-line analysis on a standard desktop computer, after the selection of the most suitable sorting methods. This work provides a useful and versatile instrument for a supported comparison of different options for spike sorting towards more accurate off-line and on-line MEA data analysis

Conjugated PDT drug: photosensitizing activity and tissue distribution of PEGylated pheophorbide a.

The design of new photosensitizers with enhanced phototoxicity and pharmacokinetic properties remains a central challenge for cancer photodynamic therapy (PDT). In this study, Pheophorbide a (Pba) has been pegylated to methoxypolyethylene glycol (mPE G-Pba) to produce a soluble photosensitizer that exhibits a higher tissue distribution than free Pba. In vitro studies have shown that mPE G-Pba promotes a fairly strong photosensitizing effect in cancer cells, as previously observed for the unpegylated molecule. mPE G-Pba targets the mitochondria where, following photoactivation, ROS are produced which cause a cellular injury by lipid peroxidation. The effect of pegylation on the photosensitizer biodistribution has been examined in different selected organs of female mice, at different time points after intraperitoneal administration of the drug (50 μmol/Kg body weight). Other than free Pba, which showed a low tissue accumulation, mPE G-Pba has been detected in significant amounts (8 to 16 μg/ml) in liver, spleen, duodenum and kidney and, 3-5 hours after intraperitoneal injection, in moderate amounts (3 to 8 μg/ml) in brain and lung. In vivo optical imaging performed on living female C57/BL6 mice bearing a subcutaneous melanoma mass, showed that injected mPEG-Pba distributes all over the body, with an higher uptake in the tumor respect to free Pba. Our results indicate that although pegylation somewhat decreases the phototoxicity, it significantly increases the drug solubility and tissue distribution and tumor uptake of mPE G-Pba, making the conjugate an interesting photosensitizer for PDT

Targeted delivery of neutralizing anti-C5 antibody to renal endothelium prevents complement- dependent tissue damage

Complement activation is largely implicated in the pathogenesis of several clinical conditions and its therapeutic neutralization has proven effective in preventing tissue and organ damage. A problem that still needs to be solved in the therapeutic control of complement-mediated diseases is how to avoid side effects associated with chronic neutralization of the complement system, in particular, the increased risk of infections. We addressed this issue developing a strategy based on the preferential delivery of a C5 complement inhibitor to the organ involved in the pathologic process. To this end, we generated Ergidina, a neutralizing recombinant anti-C5 human antibody coupled with a cyclic-RGD peptide, with a distinctive homing property for ischemic endothelial cells and effective in controlling tissue damage in a rat model of renal ischemia/reperfusion injury (IRI). As a result of its preferential localization on renal endothelium, the molecule induced complete inhibition of complement activation at tissue level, and local protection from complement-mediated tissue damage without affecting circulating C5. The ex vivo binding of Ergidina to surgically removed kidney exposed to cold ischemia supports its therapeutic use to prevent posttransplant IRI leading to delay of graft function. Moreover, the finding that the ex vivo binding of Ergidina was not restricted to the kidney, but was also seen on ischemic heart, suggests that this RGD-targeted anti-C5 antibody may represent a useful tool to treat organs prior to transplantation. Based on this evidence, we propose preliminary data showing that Ergidina is a novel targeted drug to prevent complement activation on the endothelium of ischemic kidney

Limited diagnostic value of questionnaire-based pre-participation screening algorithms: A "risk-exposed" approach to sports activity

Background: Several pre-participation screening algorithms (PPSAs) have been proposed to assess sports eligibility in different populations. They are usually based on self-administered questionnaires, without further medical assessment if no risk factors are documented. The Med-Ex "Formula Benessere"worksite program includes a complete cardiovascular (CV) screening for all participants. The purpose of this study was to assess PPSAs accuracy in detecting medical and/or CV abnormalities in the general population, comparing the results with the date derived from Med-Ex program. Methods: The Med-Ex medical evaluation, consisting of medical history, physical examination (including body composition), resting electrocardiogram (ECG) and exercise stress test in 464 male subjects (38.4 aged) was analyzed and matched to several PPSAs - Physical Activity Readiness Questionnaire (PAR-Q) (2002-2020), American Heart Association (AHA)/American College of Sport Medicine (ACSM) (1998-2009-2014-2015), European Association of Cardiovascular Prevention and Rehabilitation (EACPR) (2011) - retrospectively simulated. Results: Five-hundred and 67 abnormalities were detected though Med-Ex medical evaluation, and one-fourth (24%) would have been undetected applying PPSA alone. In particular 28% of high blood pressure, 21% of impaired fasting glycaemia, 21% of high Body Mass Index (BMI) values and 19% of ECG abnormalities would have been missed, on average, by all PPSAs. Conclusions: The simulation analysis model performed in this study allowed to highlight the limits of PPSAs in granting sport eligibility, compared to a medical-guided CV screening. These findings emphasize the importance of a more balanced approach to pre-participation screening that includes a thorough evaluation of the cost/benefit ratio