Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

The Green Approach to the Synthesis of Bio-Based Thermoplastic Polyurethane Elastomers with Partially Bio-Based Hard Blocks

Bio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal, thermomechanical, and mechanical properties of obtained bio-TPUs. Diisocyanate mixture and bio-based 1,4-butanediol (as a low molecular chain extender) created bio-based hard blocks (HS). The diisocyanate mixture contained up to 75 wt % of partially bio-based diisocyanate. It is worth mentioning that the structure and amount of HS impact the phase separation, processing, thermal or mechanical properties of polyurethanes. The soft blocks (SS) in the bio-TPU’s materials were built from α,ω-oligo(ethylene-butylene adipate) diol. Hereby, bio-TPUs differed in hard segments content (c.a. 30; 34; 40, and 53%). We found that already increase of bio-based diisocyanate content of the bio-TPU impact the changes in their thermal stability which was measured by TGA. Based on DMTA results we observed changes in the viscoelastic behavior of bio-TPUs. The DSC analysis revealed decreasing in glass transition temperature and melting temperature of hard segments. In general, obtained materials were characterized by good mechanical properties. The results confirmed the validity of undertaken research problem related to obtaining bio-TPUs consist of bio-based hard building blocks. The application of partially bio-based diisocyanate mixtures and bio-based chain extender for bio-TPU synthesis leads to sustainable chemistry. Therefore the total level of “green carbons” increases with the increase of bio-based diisocyanate content in the bio-TPU structure. Obtained results constitute promising data for further works related to the preparation of fully bio-based thermoplastic polyurethane elastomers and development in the field of bio-based polymeric materials

Thermoplastic bio-polyurethane elastomers synthesized with two bio-based monomers

Celem niniejszej pracy było zbadanie wpływu monomerów pochodzenia roślinnego na wybrane właściwości nowych termoplastycznych elastomerów poliuretanowych. Przygotowane w pracy materiały otrzymano metodą dwuetapową (prepolimerową) z wykorzystaniem petrochemicznego diizocyjanianu oraz dwóch monomerów pochodzenia roślinnego (odnawialnego): biopoliolu i bioglikolu. Zbadano także wpływ stosunku molowego grup izocyjanianowych [NCO] do hydroksylowych [OH] podczas przedłużania łańcucha prepolimeru uretanowego na właściwości przygotowanych materiałów. Za pomocą techniki FTIR-ATR potwierdzono budowę chemiczną otrzymanych biopoliuretanów. Wybrane właściwości mechaniczne określono za pomocą próby wytrzymałościowej przy statycznym rozciąganiu, a właściwości termomechaniczne wyznaczono na podstawie analizy termicznej dynamicznych właściwości mechanicznych (DMTA).The aim of this work was to investigate the influence of renewable origin monomers on selected properties of new thermoplastic polyurethane elastomers. Materials were synthesized by a prepolymer method with using petrochemical diisocyanate and two bio-based monomers: bio-polyol and bio-glycol. The effect of molar ratio of isocyanate [NCO] to hydroxyl [OH] groups during extension of the urethane prepolymer chains on the selected properties of prepared materials was also investigated. The chemical structure of the obtained bio-polyurethanes was confirmed by the FTIR-ATR technique. The influence of molar ratio [NCO]/[OH] on the mechanical properties (i.e. tensile properties, hardness), and dynamic mechanical properties (storage modulus, loss Modulus and damping factor) of produced polyurethanes was examined

Natural rubber vulcanizates obtained with the use of plasticizers from renewable resources

The aim of this research was to investigate the impact of epoxidized natural oils on natural rubbers vulcanizates selected properties. Epoxidized soybean oil and epoxidized palm oil were used as a plasticizers. The impact of this two types of oils on selected properties of prepared vulcanizates was compared with reference samples prepared without plasticizer usage and with the use of naphthenic oil. The influence of the type and amount of applied plasticizer on the vulcanization time was investigated and the properties of the obtained vulcanizates under static stretching were analyzed. In addition, the hardness and elasticity were measured, and the abrasiveness of the vulcanizates was examined. In order to determine the thermomechanical properties of the obtained materials, selected vulcanizates were also subjected to DMA analysis. It was found that the addition of epoxidized natural oils with maximum of 5 phr led to improvement of selected mechanical properties of the natural rubber vulcanizates.Celem niniejszej pracy było zbadanie wpływu epoksydowanych olejów roślinnych na wybrane właściwości wulkanizatów kauczuku naturalnego. Jako plastyfikatorów użyto epoksydowanego oleju sojowego oraz epoksydowanego oleju palmowego. Wpływ olejów naturalnych porównano także z wulkanizatami przygotowanymi bez użycia zmiękczaczy, jak i zawierającymi olej maszynowy, pochodzący z przerobu ropy naftowej. Zbadano wpływ rodzaju oraz ilości zastosowanego plastyfikatora na czas wulkanizacji oraz przeprowadzono analizę właściwości otrzymanych wulkanizatów przy statycznym rozciąganiu. Ponadto, wykonano pomiar twardości oraz elastyczności przy odbiciu, a także zbadano ścieralność wulkanizatów. W celu określenia właściwości termomechanicznych otrzymanych materiałów, wybrane wulkanizaty poddano również analizie DMA. Stwierdzono, że dodatek epoksydowanych olejów naturalnych w ilości do 5 phr wpływa na poprawę wybranych właściwości mechanicznych otrzymanych wulkanizatów kauczuku naturalnego

Zielone termoplastyczne elastomery poli(etero-uretanowe) – synteza i badania struktury chemicznej oraz wybranych właściwości

This work aimed to characterize the effect of the monomers chemical structure on the selected properties of the green thermoplastic poly(ether-urethane)s. During synthesis two types of polyether biopolyols, 4,4′-diphenylmethane diisocyanate and bio-based 1,3-propanediol were employed. Materials were synthesized with the use of two step method and two different prepolymers, which were mixed together in equimolar quantities. Obtained materials were characterized by spectroscopic method, size exclusion chromatography, thermal, static mechanical and melt flow index tests. It was confirmed that the prepolymers mixture has an effect on the thermal stability and selected properties of synthesized green thermoplastic poly(ether-urethane)s.Zbadano wpływ struktury chemicznej monomerów na wybrane właściwości zielonych termoplastycznych elastomerów poli(etero-uretanowych). W syntezie wykorzystano dwa rodzaje biopolioli polieterowych, 4,4’-diizocyjanian difenylometanu oraz 1,3-propanodiol pochodzenia roślinnego. Materiały zsyntezowano z wykorzystaniem dwustopniowej metody, w której zastosowano równomolową mieszaninę dwóch prepolimerów. Otrzymane materiały scharakteryzowano za pomocą metod spektroskopowych, chromatografii żelowej, w statycznej próbie rozciągania, w badaniach termicznych oraz na podstawie wskaźnika szybkości płynięcia. Stwierdzono, że mieszanina prepolimerów wpływa na stabilność termiczną oraz wybrane właściwości otrzymanych zielonych termoplastycznych elastomerów poli(etero-uretanowych)

Radiosensitization of PC3 Prostate Cancer Cells by 5-Thiocyanato-2′-deoxyuridine

Purpose: The radiosensitizing properties of uracil analogs modified in the C5 position are very interesting in the context of their effectiveness and safety in radiation therapy. Recently, radiation chemical studies have confirmed that 5-thiocyanato-2′-deoxyuridine (SCNdU) undergoes dissociation induced by an excess electron attachment and established this nucleoside as a potential radiosensitizer. In this paper, we verify the sensitizing properties of SCNdU at the cellular level and prove that it can effectively enhance ionizing radiation-induced cellular death. Methods and Materials: Prostate cancer cells were treated with SCNdU and irradiated with X rays. The cytotoxicity of SCNdU was determined by MTT test. Cell proliferation was assessed using a clonogenic assay. Cell cycle analyses, DNA damage, and cell death analyses were performed by flow cytometry. Results: SCNdU treatment significantly suppressed the proliferation and increased the radiosensitivity of prostate cancer cells. The radiosensitizing effect expressed by the dose enhancement factor is equal to 1.69. Simultaneous exposure of cells to SCNdU and radiation causes an increase in the fraction of the most radiosensitive G2/M phase, enhancement of the histone H2A.X phosphorylation level, and apoptosis induction. Finally, SCNdU turned out to be marginally cytotoxic in the absence of ionizing radiation. Conclusions: Our findings indicate that SCNdU treatment enhances the radiosensitivity of prostate cancer cells in a manner associated with the cell cycle regulation, double strand formation, and a slight induction of apoptosis