Efficient cellular and humoral immune response and production of virus-neutralizing antibodies by the Hepatitis B Virus S/preS1 16-42 antigen

Despite the availability of improved antiviral therapies, infection with Hepatitis B virus (HBV) remains a3 significant health issue, as a curable treatment is yet to be discovered. Current HBV vaccines relaying on the efficient expression of the small (S) envelope protein in yeast and the implementation of mass vaccination programs have clearly contributed to containment of the disease. However, the lack of an efficient immune response in up to 10% of vaccinated adults, the controversies regarding the seroprotection persistence in vaccine responders and the emergence of vaccine escape virus mutations urge for the development of better HBV immunogens. Due to the critical role played by the preS1 domain of the large (L) envelope protein in HBV infection and its ability to trigger virus neutralizing antibodies, including this protein in novel vaccine formulations has been considered a promising strategy to overcome the limitations of S only-based vaccines. In this work we aimed to combine relevant L and S epitopes in chimeric antigens, by inserting preS1 sequences within the external antigenic loop of S, followed by production in mammalian cells and detailed analysis of their antigenic and immunogenic properties. Of the newly designed antigens, the S/preS116–42 protein assembled in subviral particles (SVP) showed the highest expression and secretion levels, therefore, it was selected for further studies in vivo. Analysis of the immune response induced in mice vaccinated with S/preS116–42- and S-SVPs, respectively, demonstrated enhanced immunogenicity of the former and its ability to activate both humoral and cellular immune responses. This combined activation resulted in production of neutralizing antibodies against both wild-type and vaccine-escape HBV variants. Our results validate the design of chimeric HBV antigens and promote the novel S/preS1 protein as a potential vaccine candidate for administration in poor-responders to current HBV vaccines.publishedVersio

Efficient cellular and humoral immune response and production of virus-neutralizing antibodies by the Hepatitis B Virus S/preS116-42 antigen

Despite the availability of improved antiviral therapies, infection with Hepatitis B virus (HBV) remains a3 significant health issue, as a curable treatment is yet to be discovered. Current HBV vaccines relaying on the efficient expression of the small (S) envelope protein in yeast and the implementation of mass vaccination programs have clearly contributed to containment of the disease. However, the lack of an efficient immune response in up to 10% of vaccinated adults, the controversies regarding the seroprotection persistence in vaccine responders and the emergence of vaccine escape virus mutations urge for the development of better HBV immunogens. Due to the critical role played by the preS1 domain of the large (L) envelope protein in HBV infection and its ability to trigger virus neutralizing antibodies, including this protein in novel vaccine formulations has been considered a promising strategy to overcome the limitations of S only-based vaccines. In this work we aimed to combine relevant L and S epitopes in chimeric antigens, by inserting preS1 sequences within the external antigenic loop of S, followed by production in mammalian cells and detailed analysis of their antigenic and immunogenic properties. Of the newly designed antigens, the S/preS116–42 protein assembled in subviral particles (SVP) showed the highest expression and secretion levels, therefore, it was selected for further studies in vivo. Analysis of the immune response induced in mice vaccinated with S/preS116–42- and S-SVPs, respectively, demonstrated enhanced immunogenicity of the former and its ability to activate both humoral and cellular immune responses. This combined activation resulted in production of neutralizing antibodies against both wild-type and vaccine-escape HBV variants. Our results validate the design of chimeric HBV antigens and promote the novel S/preS1 protein as a potential vaccine candidate for administration in poor-responders to current HBV vaccines

One-pot synthesis of superabsorbant hybrid hydrogels based on methacrylamide gelatin and polyacrylamide: effortless control of hydrogel properties through composition design

BiocompatibLe methacryLamide-modified geLatin (GELMA) hydrogeLs with tuned characteristics, obtained through network-forming photopoLymerization, have recenty attracted increasing attention due to their wide range of possibLe appLications such as drug reLease, tissue regeneration and generation of bioartificiaL impLants. Due to the controlled number of C=C bonds, GELMA may simuLtaneousLy act as macromonomer and crossLinker Leading through poLymerization to hydrogeLs with rationally designed performances. This study provides effortess one-pot synthesis of hybrid hydrogeLs based on covaLenty Linked GELMA and poLyacryLamide (PM), using photo-induced network-forming poLymerization. ConventionaL synthesis of simiLar hydrogeLs Leads to interpenetrating geLatin and PAA networks, usually invoLving muLtistep crossLinking of the components and the use of toxic crossLinkers. Through the described one-pot chemistry, the synthetic water superabsorbent PM with its well-recognized advantages can rationally benefit from the high biocompatibiLity and cell-adherence of GELMA in a simpLe covaLent way. This work provides a correLation between the composition and the corresponding hydrogeL properties (incLuding swelling, pH influence, mechanicaL behaviour, abiLity to generate porous scaffoLds, enzymatic degradation). The addition of PM moduLated the network density and the water affinity allowing the controL of eLasticity and degradabiLity. SuppLementary crossLinking of the synthetic component provided additionaL controL over hydrophiLicity. The capacity of such hydrogeLs to generate porous scaffoLds was proved; interesting morphoLogies were deveLoped onLy by varying the composition. In vitro ceLLuLar studies indicated that the presence of GELMA conferred controlled cell-affinity properties to the bicomponent hydrogeLs. NevertheLess, the drug reLease potentiaL of such hydrogeLs was preLiminarlly investigated using sodium nafcillin. GELMA PM hydrogeLs may be usefuL for tissue regeneration due to effortess synthesis, compositionaL flexibiLity and variabLe properties

Optimized Technologies for Cointegration of MOS Transistor and Glucose Oxidase Enzyme on a Si-Wafer

The biosensors that work with field effect transistors as transducers and enzymes as bio-receptors are called ENFET devices. In the actual paper, a traditional MOS-FET transistor is cointegrated with a glucose oxidase enzyme, offering a glucose biosensor. The manufacturing process of the proposed ENFET is optimized in the second iteration. Above the MOS gate oxide, the enzymatic bioreceptor as the glucose oxidase is entrapped onto the nano-structured TiO2 compound. This paper proposes multiple details for cointegration between MOS devices with enzymatic biosensors. The Ti conversion into a nanostructured layer occurs by anodization. Two cross-linkers are experimentally studied for a better enzyme immobilization. The final part of the paper combines experimental data with analytical models and extracts the calibration curve of this ENFET transistor, prescribing at the same time a design methodology

Synthesis of ZnO/Au Nanocomposite for Antibacterial Applications

Annually, antimicrobial-resistant infections-related mortality worldwide accelerates due to the increased use of antibiotics during the coronavirus pandemic and the antimicrobial resistance, which grows exponentially, and disproportionately to the current rate of development of new antibiotics. Nanoparticles can be an alternative to the current therapeutic approach against multi-drug resistance microorganisms caused infections. The motivation behind this work was to find a superior antibacterial nanomaterial, which can be efficient, biocompatible, and stable in time. This study evaluated the antibacterial activity of ZnO-based nanomaterials with different morphologies, synthesized through the solvothermal method and further modified with Au nanoparticles through wet chemical reduction. The structure, crystallinity, and morphology of ZnO and ZnO/Au nanomaterials have been investigated with XRD, SEM, TEM, DLS, and FTIR spectroscopy. The antibacterial effect of unmodified ZnO and ZnO/Au nanomaterials against Escherichia coli and Staphylococcus aureus was investigated through disc diffusion and tetrazolium/formazan (TTC) assays. The results showed that the proposed nanomaterials exhibited significant antibacterial effects on the Gram-positive and Gram-negative bacteria. Furthermore, ZnO nanorods with diameters smaller than 50 nm showed better antibacterial activity than ZnO nanorods with larger dimensions. The antibacterial efficiency against Escherichia coli and Staphylococcus aureus improved considerably by adding 0.2% (w/w) Au to ZnO nanorods. The results indicated the new materials’ potential for antibacterial applications

Lipopolysaccharide-induced inflammation in monocytes/macrophages is blocked by liposomal delivery of Gi-protein inhibitor

Monica Madalina Tucureanu,1,* Daniela Rebleanu,1,* Cristina Ana Constantinescu,1,2 Mariana Deleanu,3,4 Geanina Voicu,1 Elena Butoi,1 Manuela Calin,1 Ileana Manduteanu1 1Department of Biopathology and Therapy of Inflammation, Nicolae Simionescu Institute of Cellular Biology and Pathology, Bucharest, Romania; 2Faculty of Veterinary Medicine, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania; 3Department of Lipidomics, Nicolae Simionescu Institute of Cellular Biology and Pathology, Bucharest, Romania; 4Faculty of Biotechnologies, University of Agronomic Sciences and Veterinary Medicine, Bucharest, Romania *These authors contributed equally to this work Background: Lipopolysaccharide (LPS) is widely recognized as a potent activator of monocytes/macrophages, and its effects include an altered production of key mediators, such as inflammatory cytokines and chemokines. The involvement of Gi protein in mediating LPS effects has been demonstrated in murine macrophages and various cell types of human origin. Purpose: The aim of the present work was to evaluate the potential of a Gi-protein inhibitor encapsulated in liposomes in reducing the inflammatory effects induced by LPS in monocytes/macrophages. Materials and methods: Guanosine 5´-O-(2-thiodiphosphate) (GOT), a guanosine diphosphate analog that completely inhibits G-protein activation by guanosine triphosphate and its analogs, was encapsulated into liposomes and tested for anti-inflammatory effects in LPS-activated THP1 monocytes or THP1-derived macrophages. The viability of monocytes/macrophages after incubation with different concentrations of free GOT or liposome-encapsulated GOT was assessed by MTT assay. MAPK activation and production of IL1β, TNFα, IL6, and MCP1 were assessed in LPS-activated monocytes/macrophages in the presence or absence of free or encapsulated GOT. In addition, the effect of free or liposome-encapsulated GOT on LPS-stimulated monocyte adhesion to activated endothelium and on monocyte chemotaxis was evaluated. Results: We report here that GOT-loaded liposomes inhibited activation of MAPK and blocked the production of the cytokines IL1β, TNFα, IL6, and MCP1 induced by LPS in monocytes and macrophages. Moreover, GOT encapsulated in liposomes reduced monocyte adhesion and chemotaxis. All demonstrated events were in contrast with free GOT, which showed reduced or no effect on monocyte/macrophage activation with LPS. Conclusion: This study demonstrates the potential of liposomal GOT in blocking LPS proinflammatory effects in monocytes/macrophages. Keywords: guanosine 5´-O-(2-thiodiphosphate) (GOT), MAPK activation, cytokine, monocyte adhesion, chemotaxi

The Specific Molecular Changes Induced by Diabetic Conditions in Valvular Endothelial Cells and upon Their Interactions with Monocytes Contribute to Endothelial Dysfunction

Aortic valve disease (AVD) represents a global public health challenge. Research indicates a higher prevalence of diabetes in AVD patients, accelerating disease advancement. Although the specific mechanisms linking diabetes to valve dysfunction remain unclear, alterations of valvular endothelial cells (VECs) homeostasis due to high glucose (HG) or their crosstalk with monocytes play pivotal roles. The aim of this study was to determine the molecular signatures of VECs in HG and upon their interaction with monocytes in normal (NG) or high glucose conditions and to propose novel mechanisms underlying valvular dysfunction in diabetes. VECs and THP-1 monocytes cultured in NG/HG conditions were used. The RNAseq analysis revealed transcriptomic changes in VECs, in processes related to cytoskeleton regulation, focal adhesions, cellular junctions, and cell adhesion. Key molecules were validated by qPCR, Western blot, and immunofluorescence assays. The alterations in cytoskeleton and intercellular junctions impacted VEC function, leading to changes in VECs adherence to extracellular matrix, endothelial permeability, monocyte adhesion, and transmigration. The findings uncover new molecular mechanisms of VEC dysfunction in HG conditions and upon their interaction with monocytes in NG/HG conditions and may help to understand mechanisms of valvular dysfunction in diabetes and to develop novel therapeutic strategies in AVD

Preparation and characterization of YAG:Ce thin phosphor films by pulsed laser deposition

International audienceWe report the use of YAG:Ce phosphor as the raw material to make thin and transparent phosphor films with pulsed laser deposition including the effects of heating temperature, target–substrate distances, annealing times, and annealing atmosphere on the YAG:Ce3+ phosphor film crystal types and spectral properties. The results indicated that at a coating temperature of 350°C, the YAG:Ce3+ phosphor film had the best crystallinity with an intact film and maximum fluorescence emission. The crystallinity and fluorescence emission intensity of the film gradually decreased as a function of increasing target–substrate distances. As the annealing time increased, the crystallinity and the fluorescence emission intensity of the film first increased and then decreased. The film made with 5 h of annealing had the best crystallinity and the highest fluorescence emission intensity. The crystallinity of the film annealed under air was higher than that made under nitrogen; the fluorescence intensity of the film under air was slightly lower than the film under nitrogen. The emission peak of the prepared film was at 523 nm when excited at 450 nm. This is slightly blue-shifted versus the emission of commercial phosphor powders. This study offers a theoretical basis for the development of transparent phosphor films. © 2016 The American Ceramic Societ

Dielectrophoretic and Electrical Impedance Differentiation of Cancerous Cells Based on Biophysical Phenotype

Here, we reported a study on the detection and electrical characterization of both cancer cell line and primary tumor cells. Dielectrophoresis (DEP) and electrical impedance spectroscopy (EIS) were jointly employed to enable the rapid and label-free differentiation of various cancer cells from normal ones. The primary tumor cells that were collected from two colorectal cancer patients, cancer cell lines (SW-403, Jurkat, and THP-1), and healthy peripheral blood mononuclear cells (PBMCs) were trapped first at the level of interdigitated microelectrodes with the help of dielectrophoresis. Correlation of the cells dielectric characteristics that was obtained via electrical impedance spectroscopy (EIS) allowed evident differentiation of the various types of cell. The differentiations were assigned to a “dielectric phenotype” based on their crossover frequencies. Finally, Randles equivalent circuit model was employed for highlighting the differences with regard to a series group of charge transport resistance and constant phase element for cancerous and normal cells