Extracellular Vesicle-based Nano/Microparticles for Novel Vaccination Approaches

Pneumococcal infections cause many fatalities worldwide. Growing resistance to antibiotics and incomplete coverage of available vaccines against all serotypes made the search for novel vaccination approaches a global necessity. Extracellular membrane vesicles are secreted nanostructures, which are physiologically secreted from seemingly all living cells and harbor their virulence factors and immunogenic components. In this work, several research objectives were explored: (i) Isolation and characterization of pneumococcal vesicles. (ii) Biocompatibility and uptake with cell lines and primary human cells. (iii) Yield Enhancement of pneumococcal vesicles. (iv) Immunostimulation of immune cells by pneumococcal vesicles. (v) Formulation of spray-dried vaccine microparticles for pulmonary immunization. The isolated vesicles exhibited excellent biocompatibility with several cell lines and primary cells, without cytotoxic effects. Pneumococcal vesicles demonstrated rapid uptake into immune cells and stimulated the release of pro-inflammatory cytokines. We successfully formulated spray-dried vaccine microparticles with enhanced stability and increased cytokine release for pulmonary delivery. Our findings confirm the strong potential of pneumococcal membrane vesicles as vaccine candidates, and provide a sound basis for further translation and scale-up for pulmonary delivery and immunization.Pneumokokken-Infektionen führen weltweit zu zahlreichen Todesfällen. Die zunehmende Resistenz gegen Antibiotika und die unvollständige Abdeckung durch verfügbare Impfstoffe gegen alle Serotypen machen die Suche nach neuen Impfansätzen eine globale Notwendigkeit. Extrazelluläre Membranvesikel sind sezernierte Nanostrukturen, die von ziemlich allen Zellen ausgeschieden werden und ihre Virulenzfaktoren und immunogenen Komponenten beherbergen. In dieser Arbeit wurden mehrere Forschungsziele verfolgt: (i) Isolierung und Charakterisierung von Pneumokokken-Vesikeln. (ii) Biokompatibilität und Aufnahme gegenüber Zelllinien und primären menschlichen Zellen. (iii) Erhöhung der Ausbeute. (iv) Immunstimulation von Immunzellen durch Pneumokokken-Vesikel. (v) Formulierung von sprühgetrockneten Impfstoff-Mikropartikeln für die Immunisierung der Lunge. Die isolierten Vesikel zeigten eine ausgezeichnete Biokompatibilität mit verschiedenen Zelllinien und Primärzellen. Pneumokokken-Vesikel zeigten eine schnelle Aufnahme in Immunzellen und stimulierten die Freisetzung von proinflammatorischen Zytokinen. Sprühgetrocknete Impfstoff-Mikropartikel wurden mit verbesserter Stabilität und erhöhter Zytokinfreisetzung für die pulmonale Verabreichung formuliert. Unsere Ergebnisse bestätigen das große Potenzial von Pneumokokken-Membranvesikeln als Impfstoffkandidaten und bilden eine wichtige Grundlage für die weitere Umsetzung und das Scale-up für die pulmonale Verabreichung und Immunisierung.PhD fellowship (German-Egyptian Research Long-term Scholarship) from the German Academic Exchange Service (DAAD) and Egyptian Ministry of Higher Education. NanoMatFutur grant from the Federal Ministry of Education and Research

Structural Optimization of Wind Turbine Blades for Improved Dynamic Performance

The design of the main structure of a wind turbine blade is optimized aiming at the improvement of the overall dynamic performance. Three optimization strategies are developed and tested. The first fundamental one is based on minimizing the total structural mass of the blade spar under frequency and strength constraints. The second and third strategies are concerned with the reduction of the overall vibration level by either minimizing a frequency-placement index or maximizing the natural frequencies and placing them at their target values to avoid large amplitudes and resonance occurrence. Design variables include cross-sectional dimensions and material properties along the spanwise direction of the blade spar. The optimization problem is formulated as a nonlinear constrained problem solved by sequential quadratic programming (SQP) technique. Two specific layup configurations, namely, circumferentially asymmetric stiffness ( CAS ) and circumferentially uniform stiffness ( CUS ), are analyzed. Exact analytical methods are applied to calculate the natural modes of vibration of a composite, thin-walled, tapered blade spar. The influence of coupling on the vibration modes is identified, and the functional behavior of the frequencies with the lamination parameters is thoroughly investigated and discussed. Finite element modeling using NX Nastran solver is performed in order to validate the analytical results. As a case study, optimized blade spar designs of a 750-kW horizontal axis wind turbine are given. The attained solutions show that the approach used in this study enhances the dynamic characteristics of the optimized spar structures as compared with a known baseline design of the wind turbine blade

High-Content Lignocellulosic Fibers Reinforcing Starch-Based Biodegradable Composites: Properties and Applications

Natural source-based composites became promising substitutes and synthetic petrochemical-based counterparts. So far, thermoplastic starch and lignocellulosic fibers are the most common materials for making such eco-friendly ?green? materials. Low cost, abundance, and renewability are the factors that lead to deploying these two types of materials. In this chapter, we are conducting further analysis for previously published results of six types of high-content natural fiber-reinforced starch-based composites. All composites were prepared by compression molding under pressure from 5 to 20 MPa and temperature from 130 to 160°C. Composites exhibited highest tensile strength and modulus of elasticity at fiber weight content from 50 to 70%, and then mechanical properties deteriorated significantly at 80% fiber content due to the insufficient starch resin. For instance, the tensile strength was boosted up from 2-12 MPa for thermoplastic starch to reach 55, 45, 32, 28, 44, 365 MPa for flax, bagasse, date palm fiber (DPF), banana, bamboo, and hemp composites, when fiber content was increased from 0% to the optimum fiber content (50-70%). Kelly-Tyson (random 2d) was the optimum model to predict random fiber composite. Increasing the fiber content and choosing a fiber with high cellulose content significantly improve the moisture resistance of the composites. Fick’s law of diffusion predicted the water uptake property successfully. The thermal stability of composites was improved with increasing the fiber weight content as well. This is attributed to the high thermal stability of cellulose when compared to starch. Properties exhibited by starch-based high-content natural fiber composite are promising for many industrial and biomedical applications

Extraction and characterization of nanocellulose from three types of palm residues

Carbon footprint and nonrenewability are among the motives to mitigate dependence on oil resources. On the other hand, palm trees exceeded 100 million around globe, which poses enormous amount of biowastes to get exploited per annum. Moreover, nanocellulose is emerging as efficient low cost material, which shows increasing versatility throughout time. In this investigation we will attempt to extract nanocellulose from palm wastes (fronds, leaves, and coir), and characterize them. Dry biomass was pulped by being subjected to 10% (wt/wt) NaOH alkaline treatment at 160 C for 2 h. Pulped non-bleached biomass underwent acidic hydrolysis by mechanical stirring in 20% H2SO4 (v/v) and heating to 120 C for 30 min. After filtration, neutralization, and centrifugion, resultant particles were characterized to assess their morphology, size, particle charge, existing chemical groups, and crystallinity. For the three types of palm residues, our preparation technique was successful to isolate lignin containing nanocellulose particles. However, coir was more recalcitrant to acidic hydrolysis than fronds and leaves. Our palm residues yielded 42 e82 nm spherical particles, and zeta potential ranging between 11 and 19 mV. Crystallinity was higher after pulping, and lower after hydrolysis, which suggests promotion of amorphous content of cellulose. Lignin-containing nanocellulose prepared in this study initiates promising horizon especially in heavy metal (cations) removal from water in environmental applications and sustained drug delivery for medical applications.European Commissio

Spanish Poplar Biomass as a Precursor for Nanocellulose Extraction

The effect of acidic hydrolysis duration on nanocellulose size, morphology, and proper ties was investigated, which opens up a whole new horizon of versatility in poplar applications. This study aimed to examine Spanish poplar wastes as raw material to extract crystalline nanocellulose (CNC), which substantiates the importance of poplar wastes. Wastes were pulped using 1 L of 10% NaOH (wt./wt.) solution, and bleached several times by NaClO2 ; afterwards, white wastes were subjected to acidic hydrolysis by 60% H2SO4 for either 5, 10, or 15 min. Microcrystalline cellulose (MCC) underwent a similar hydrolysis protocol as poplar as control. TEM, IR, and XRD characterization techniques were performed. Poplar based nanocellulose sized 219 nm length and 69 nm width after 15 min acidic hydrolysis. MCC yielded 122 nm length and 12 nm width crystals after 10 min acidic hydrolysis. Hydrolysis resulted in a drastic change and intense peaks at 3500 and 2900 cm−1 for nanocellulose. Although pre-hydrolysis fiber treatment was not influencial on the crystallinity of poplar, acidic hydrolysis remarkably raised the crystallinity index (CI) by 7–8%. The more hydrolysis duration was prolonged, the size of the resulting crystal (whisker) decreased, and the aspect ratio increased. Hydrolysis was more impactful on MCC than poplar. However, for future work, it seems that longer duration of pulping and bleaching could have significantly removed unwanted components (hemicellulose and lignin), showcased in IR and XRD, and hence smoothened the following hydrolysis.European Union under umbrella of Erasmus+ KA107 PhD Mobility schem

Yields and Immunomodulatory Effects of Pneumococcal Membrane Vesicles Differ with the Bacterial Growth Phase

Streptococcus pneumoniae infections are a leading cause of death worldwide. Bacterial membrane vesicles (MVs) are promising vaccine candidates because of the antigenic components of their parent microorganisms. Pneumococcal MVs exhibit low toxicity towards several cell lines, but their clinical translation requires a high yield and strong immunogenic effects without compromising immune cell viability. MVs are isolated during either the stationary phase (24 h) or death phase (48 h), and their yields, immunogenicity and cytotoxicity in human primary macrophages and dendritic cells have been investigated. Death-phase vesicles showed higher yields than stationary-phase vesicles. Both vesicle types displayed acceptable compatibility with primary immune cells and several cell lines. Both vesicle types showed comparable uptake and enhanced release of the inflammatory cytokines, tumor necrosis factor and interleukin-6, from human primary immune cells. Proteomic analysis revealed similarities in vesicular immunogenic proteins such as pneumolysin, pneumococcal surface protein A, and IgA1 protease in both vesicle types, but stationary-phase MVs showed significantly lower autolysin levels than death-phase MVs. Although death-phase vesicles produced higher yields, they lacked superiority to stationary-phase vesicles as vaccine candidates owing to their similar antigenic protein cargo and comparable uptake into primary human immune cells

Potential of Lignin Valorization with Emphasis on Bioepoxy Production

Lignin is the second most abundant natural polymer after cellulose. It has high molecular weight and poor dispersity, which lowers its compatibility with other polymeric materials. Accordingly, it is hard to integrate lignin into polymer-based applications in its native form. Recently, lignin valorization, which aims to boost lignin value and reactivity with other materials, has captured the interest of many researchers. The volatility of oil and gas prices is one strong incentive for them to consider lignin as a potential replacement for many petroleum-based materials. In this chapter, lignin valorization processes, namely hydrogenolysis, pyrolysis, hydro-thermal liquefaction, and hydro-thermal carbonization, are discussed in brief. The chapter also discusses the synthesis of lignin-based epoxy resin as an already existing example of a lignin-based product

A combined local damage index for seismic assessment of existing RC structures

A new local damage index for existing reinforced concrete (RC) structures is introduced, wherein deterioration caused by all deformation mechanisms (flexure, shear, anchorage slip) is treated separately for each mechanism. Moreover, the additive character of damage arising from the three response mechanisms, as well as the increase in degradation rate caused by their interaction, are fully taken into consideration. The proposed local damage index is then applied, in conjunction with a finite element model developed previously by the authors, to assess seismic damage response of several RC column and frame test specimens with substandard detailing. It is concluded that in all cases and independently from the prevailing mode of failure, the new local damage index describes well the damage pattern of the analysed specimens

The Effects of Cocaine on Different Redox Forms of Cysteine and Homocysteine, and on Labile, Reduced Sulfur in the Rat Plasma Following Active versus Passive Drug Injections

Received: 28 November 2012 / Revised: 19 April 2013 / Accepted: 6 May 2013 / Published online: 16 May 2013 The Author(s) 2013. This article is published with open access at Springerlink.comThe aim of the present studies was to evaluate cocaine-induced changes in the concentrations of different redox forms of cysteine (Cys) and homocysteine (Hcy), and products of anaerobic Cys metabolism, i.e., labile, reduced sulfur (LS) in the rat plasma. The above-mentioned parameters were determined after i.p. acute and subchronic cocaine treatment as well as following i.v. cocaine self-administration using the yoked procedure. Additionally, Cys, Hcy, and LS levels were measured during the 10-day extinction training in rats that underwent i.v. cocaine administration. Acute i.p. cocaine treatment increased the total and protein-bound Hcy contents, decreased LS, and did not change the concentrations of Cys fractions in the rat plasma. In turn, subchronic i.p. cocaine administration significantly increased free Hcy and lowered the total and protein-bound Cys concentrations while LS level was unchanged. Cocaine self-administration enhanced the total and protein-bound Hcy levels, decreased LS content, and did not affect the Cys fractions. On the other hand, yoked cocaine infusions did not alter the concentration of Hcy fractions while decreased the total and protein-bound Cys and LS content. This extinction training resulted in the lack of changes in the examined parameters in rats with a history of cocaine self-administration while in the yoked cocaine group an increase in the plasma free Cys fraction and LS was seen. Our results demonstrate for the first time that cocaine does evoke significant changes in homeostasis of thiol amino acids Cys and Hcy, and in some products of anaerobic Cys metabolism, which are dependent on the way of cocaine administration

Engineering Structures A probabilistic boundary element method applied to the pile dislocation problem

a b s t r a c t In this paper a probabilistic approach is presented where the boundary element method is efficiently used to study the effect of a random shift of a given pile within a particular pile cap from its original position -the so-called pile dislocation problem -on selected output design parameters such as pile loads and bending moments in the pile cap. A new circular internal element is developed to simulate the true geometric modeling of piles. The boundary element method for the shear-deformable (thick) plate theory is employed to analyze the pile cap. The plate-pile interaction forces are considered to have constant variation over the circular pile domain. The probabilistic approach presented herein incorporates a Monte Carlo simulation technique for generating random shifts in the original position of a given pre-selected pile. The procedure has been applied to some exemplar pile caps with given pile layouts typically adopted in bridge construction. The results demonstrate that the random dislocation of piles within practical ranges/values as customarily encountered for example in pile caps pertinent to bridge applications will cause limited variations in the output design parameters investigated herein and mentioned above. In other words, it has been illustrated that the resulting dispersion in the output values due to random dislocation of piles is less than the possible intrinsic dispersion that may be practically triggered in the pile locations due to common construction inaccuracies and/or unanticipated problems during pile driving process. The study further emphasizes the efficiency and reliability of the Boundary Elements Method adopted herein for such application