A highly standardized and characterized human platelet lysate for efficient and reproducible expansion of human bone marrow mesenchymal stromal cells

BackgroundHuman platelet lysate (hPL) represents a powerful alternative to fetal bovine serum (FBS) for human mesenchymal stromal cell (hMSC) expansion. However, the large variability in hPL sources and production protocols gives rise to discrepancies in product quality, characterization and poor batch-to-batch standardization.MethodshPL prepared with more than 200 donors (200+DhPL) or with five donors (5DhPL) were compared in terms of growth factor (GF) contents and biochemical analysis. A multiple protein assay and proteomic analysis were performed to further characterize 200+DhPL batches. We also compared the phenotypic and functional characteristics of bone marrow (BM)-hMSCs grown in 200+DhPL versus FBS+basic fibroblast growth factor (bFGF).ResultsBy contrast to 5DhPL, industrial 200+DhPL displayed a strong standardization of GF contents and biochemical characteristics. We identified specific plasmatic components and platelet-released factors as the most relevant markers for the evaluation of the standardization of hPL batches. We used a multiplex assay and proteomic analysis of 200+DhPL to establish a proteomic signature and demonstrated the robust standardization of batches. 200+DhPL was shown to improve and standardize BM-hMSC expansion compared with FBS+bFGF. The levels of expression of BM-hMSC membrane markers were found to be much more homogeneous between batches when cells were cultured in 200+DhPL. BM-hMSCs cultured in parallel under both conditions displayed similar adipogenic and osteogenic differentiation potential and immunosuppressive properties.ConclusionsWe report a standardization of hPL and the importance of such standardization for the efficient amplification of more homogeneous and reproducible cell therapy products.     

A novel fluorescent sensor based on electrosynthesized benzene sulfonic acid‐doped polypyrrole for determination of Pb(II) and Cu(II)

To develop conducting organic polymers (COPs) as luminescent sensors for determination of toxic heavy metals, a new benzene sulfonic acid‐doped polypyrrole (PPy‐BSA) thin film was electrochemically prepared by cyclic voltammetry (CV) on flexible indium tin oxide (ITO) electrode in aqueous solution. PPy‐BSA film was characterized by FTIR spectrometry, X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The optical properties of PPy‐BSA were investigated by ultraviolet (UV)‐visible absorption and fluorescence spectrometry in dimethylsulfoxide (DMSO) diluted solutions. PPy‐BSA fluorescence spectra were strongly quenched upon increasing copper(II) ion (Cu²⁺) and lead(II) ion (Pb²⁺) concentrations in aqueous medium, and linear Stern–Volmer relationships were obtained, which indicated the existence of a main dynamic fluorescence quenching mechanism. BSA‐PPy sensor showed a high sensitivity for detection of both metallic ions, Cu²⁺ and Pb²⁺, with very low limit of detection values of 3.1 and 18.0 nM, respectively. The proposed quenching‐fluorimetric sensor might be applied to the determination of traces of toxic heavy metallic ions in water samples.     

Effect of a Whey Protein Network Formed by Cold Gelation on Starch Digestibility

Food Biophysics - Composite gels of whey protein isolate (WPI) and potato starch (PS) were formed by calcium chloride induced cold gelation to obtain microstructures where native starch granules...     

A New Combination with D-Cateslytin to Eradicate Root Canal Pathogens

International Journal of Peptide Research and Therapeutics - The success of endodontic treatments depends on the elimination of intracanal pathogens. Since irrigation and instrumentation can only...     

Development of Vaccine Prototype Against Zika Virus Disease of Peptide-Loaded PLGA Nanoparticles and Evaluation of Cytotoxicity

Zika virus has recently evolved from an obscure mosquito-borne pathogen to an international public health concern. People with Zika virus disease can have indications including mild fever, skin rash, conjunctivitis, muscle pain, malaise or headache. Effective vaccines are needed for controlling and preventing the disease. In the current study, we aim to design the substructure for vaccine against Zika virus by forming antigenic peptide epitope of the disease. Zika peptide loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles have been fabricated in the present work as a potential artificial vaccine. UV and FT-IR Spectrophotometers and ZetaSizer were used for studying the nanoparticles, and Scanning Electron Microscope was used for morphological examination. The nanoparticles (NPs) yield, encapsulation efficiency, the peptide loading capacity were determined and in vitro release of the peptide was studied. Cytotoxic effects of the various concentrations of Zika peptide, blank PLGA nanoparticles and Zika peptide loaded PLGA nanoparticles on ECV304 human epithelial cells were determined via MTT assay. The present paper could be considered as one of the important steps in the use of nanoparticles for constructing the new generation of vaccination systems.

     

Museum specimens provide reliable SNP data for population genomic analysis of a widely distributed but threatened cockatoo species

Natural history museums harbour a plethora of biological specimens which are of potential use in population and conservation genetic studies. Although technical advancements in museum genomics have enabled genome‐wide markers to be generated from aged museum specimens, the suitability of these data for robust biological inference is not well characterized. The aim of this study was to test the utility of museum specimens in population and conservation genomics by assessing the biological and technical validity of single nucleotide polymorphism (SNP) data derived from such samples. To achieve this, we generated thousands of SNPs from 47 red‐tailed black cockatoo (Calyptorhychus banksii) traditional museum samples (i.e. samples that were not collected with the primary intent of DNA analysis) and 113 fresh tissue samples (cryopreserved liver/muscle) using a restriction site‐associated DNA marker approach (DArTseq^?). Thousands of SNPs were successfully generated from most of the traditional museum samples (with a mean age of 44 years, ranging from 5 to 123 years), although 38% did not provide useful data. These SNPs exhibited higher error rates and contained significantly more missing data compared with SNPs from fresh tissue samples, likely due to considerable DNA fragmentation. However, based on simulation results, the level of genotyping error had a negligible effect on inference of population structure in this species. We did identify a bias towards low diversity SNPs in older samples that appears to compromise temporal inferences of genetic diversity. This study demonstrates the utility of a RADseq‐based method to produce reliable genome‐wide SNP data from traditional museum specimens.     

The NAD-Booster Nicotinamide Riboside Potently Stimulates Hematopoiesis through Increased Mitochondrial Clearance

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ENSO and NAO affect long‐term leaf litter dynamics and stoichiometry of Scots pine and European beech mixedwoods

Litterfall dynamics (production, seasonality and nutrient composition) are key factors influencing nutrient cycling. Leaf litter characteristics are modified by species composition, site conditions and water availability. However, significant evidence on how large‐scale, global circulation patterns affect ecophysiological processes at tree and ecosystem level remains scarce due to the difficulty in separating the combined influence of different factors on local climate and tree phenology. To fill this gap, we studied links between leaf litter dynamics with climate and other forest processes, such as tree‐ring width (TRW) and intrinsic water‐use efficiency (iWUE) in two mixtures of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in the south‐western Pyrenees. Temporal series (18 years) of litterfall production and elemental chemical composition were decomposed following the ensemble empirical mode decomposition method and relationships with local climate, large‐scale climatic indices, TRW and Scots pine's iWUE were assessed. Temporal trends in N:P ratios indicated increasing P limitation of soil microbes, thus affecting nutrient availability, as the ecological succession from a pine‐dominated to a beech‐dominated forest took place. A significant influence of large‐scale patterns on tree‐level ecophysiology was explained through the impact of the North Atlantic Oscillation (NAO) and El Niño–Southern Oscillation (ENSO) on water availability. Positive NAO and negative ENSO were related to dry conditions and, consequently, to early needle shedding and increased N:P ratio of both species. Autumn storm activity appears to be related to premature leaf abscission of European beech. Significant cascading effects from large‐scale patterns on local weather influenced pine TRW and iWUE. These variables also responded to leaf stoichiometry fallen 3 years prior to tree‐ring formation. Our results provide evidence of the cascading effect that variability in global climate circulation patterns can have on ecophysiological processes and stand dynamics in mixed forests.