Exosomes from adipose tissue-derived stem/stromal cells: A key to future regenerative medicine

Advances in regenerative medicine correlate strongly with progress in the use of adipose tissue-derived mesenchymal stem/stromal cells. The range of therapeutic indications has also expanded over recent years. Numerous recent studies have highlighted the primary importance of paracrine secretion by these cells. Though it is interesting to compare the different types of such secretions, we believe that exosomes (extra-cellular vesicles possessing the same properties as their source cells) will likely be the main key in tomorrow’s cell therapy. Exosomes also have many advantages compared to the direct use of cells, making these particles a major target in fundamental and translational research.     

Impact of nanomaterials on plants: What other implications do they have?

The use of nanomaterials has spread and has been applied in different industries, including agriculture. Here, the possibilities presented by NMs are very varied, from the biostimulation of favorable responses, or the control of pests and diseases, to the monitoring of characteristics of interest with the use of nanosensors. Particularly the biostimulation of agricultural crops with the use of nanomaterials is very relevant, since from this process stress tolerance, higher content of biocompounds, etc., can be induced. Although the positive impacts on crops are clear, there is not enough information to determine the long-term impacts, both on ecosystems and on human health.     

PURIFICATION OF WET PROCESS PHOSPHORIC ACID BY SOLVENT EXTRACTION WITH PROPYL ETHERS.

The distribution data for the impurities (SO⁼ ₄, F^?, Fe, Al and Mg) during purification of wet phosphoric acid (WPA) with di-n-propy1 ether (DPE), di-n-propy1 ether containing 6. 5% of the isomer n-propylriso-propyl ether (DPE(M)) and di-iso-propyl ether (DIPE) at 25°C are reported. The distribution of phosphoric acid (PA)(SO⁼ ₄, F^?, Fe, Al and Mg between the conjugated phases has been investigated. The system W-WPA-DIPE shows a three-liquid-phases-at-equilibrium zone with 65.7% of phosphoric acid in the aqueous phase, 43.9% in the heavy organic phase and 4.3% in the light organic phase. The degree of purification increases, for the three solvents studied, when decreasing the PA concentration in the organic phase (except for F^?when using DPE}. Purification data for iso-arayl alcohol (1) and these three solvents are compared, showing that di-n-propyl ether with 6.5% of the isomer propyl-iso-propyl ether is the best solvent (from all solvents investigated in these series) for the purification of the wet process phosphoric acid studied.     

Polymorphism of Tricalcium Silicate and Its Solid Solutions

In tricalcium silicate and its solid solutions six modifications were established: one rhombohedral ( R ), two monoclinic ( M _I, M _II), and three triclinic ( T _I, T _II, T _III). All these forms are rhombohedral or pseudorhombohedral and extremely similar; the variations in the X-ray diagrams and the transformation enthalpies are minute. Only three of the five transitions were observed by both X rays and DTA: T _I- T _II (600°), T _III– M _I (980°), and M _I– M _II (990°); one was established by DTA ( T _II– T _III, 920°) and one by X rays only ( M _II– R , 1050°C). This scheme of polymorphism is compared critically with results of other authors, and the nature of the various displacive transformations is discussed. X-ray and DTA investigations of solid solutions of Ca₃SiO₅ with Al₂O₃ and ZnO established the phase relations as functions of temperature and composition. With Al₂O₃, two modifications ( T _I and T _II) were stabilized; and with ZnO, five polymorphs ( T _I T _II, M_I, M _II, and R ). With both pure C₃S and the solid solutions, the results are consistent and have a close bearing on the constitution of alites in portland cement clinker.     

Design of spectroelectrochemical cell for in situ X-ray absorption fine structure measurements of bulk solution species

A purpose-built spectroelectrochemical cell for in situ fluorescence XAFS (X-ray absorption fine structure) measurements of bulk solution species is described. The cell performance was demonstrated by the collection of europium L3-edge XANES (X-ray absorption near edge structure) during constant-potential electrolysis of 14.2mmEuCl3.6H2Oin1mH2SO4 aqueous electrolyte. Additionally discussed in this report are the probabilities of 2p3/25d electronic transitions pertaining to Euiii and Euii ions. Implications for the use of XANES in studying intermediate-valence materials, and some potential applications of the presently reported spectroelectrochemical cell are described.     

Dental-derived stem cells and biowaste biomaterials: What’s next in bone regenerative medicine applications

The human teeth and oral cavity harbor various populations of mesenchymal stem cells (MSCs), so called dental-derived stem cells (D-dSCs) with self-renewing and multilineage differentiation capabilities. D-dSCs properties involves a strong paracrine component resulting from the high levels of bioactive molecules they secrete in response to the local microenvironment. Altogether, this viewpoint develops a general picture of current innovative strategies to employ D-dSCs combined with biomaterials and bioactive factors for regenerative medicine purposes, and offers information regarding the available scientific data and possible applications.     

IMS USING IN-HOUSE MONOCLONAL ANTIBODY-COATED MAGNETIC BEADS ASSOCIATED TO PCR ASSAY FOR DETECTION OF SALMONELLA TYPHIMURIUM IN RAW MEATS

An immunomagnetic separation (IMS) technique and a PCR assay were developed for use in detection of Salmonella Typhimurium in meat samples. To prevent false-negative results, an internal amplification control was developed. The polymerase chain reaction (PCR) using primers specific for an omp gene sequence of Salmonella spp has shown 100% sensitivity and specificity and a detection limit of 10⁴ cfu/mL. The IMS-PCR methods using PCR immediately after IMS and using 6 h postenrichment in brain heart infusion between IMS and PCR resulted in detection limits of 10³ cfu/mL and 1–10 cfu/mL, respectively. The lowest level of S. Typhimurium that could be detected by the IMS-PCR method in the presence of natural microbiota from inoculated meat samples was 1–10 cfu/25 g. When samples were analyzed using enrichment protocols without IMS, several false-negative results were obtained.

PRACTICAL APPLICATIONS

The immunomagnetic separation-polymerase chain reaction (IMS-PCR) method developed enabled a rapid and sensitive detection of Salmonella Typhimurium in inoculated meat samples. Monoclonal antibody (Mab)-coated magnetic beads prepared in-house were efficient in concentrating and separating the bacteria from the food matrix, thus improving detection limit and avoiding false-negatives. The internal amplification control (IAC), now mandatory in PCR assays, using the same primers of the target DNA further prevented false-negative results. Therefore, the IMS-PCR method developed in this study could be used in the future by the Brazilian food industry as a substitute for the expensive imported kits for Salmonella detection in foods. We are now developing a panel of Mabs against conserved antigens of Salmonella for use in the IMS-PCR method in order to extend its applicability for detection of other serovars.     

Extending the shelf life of fresh ewe’s cheese by modified atmosphere packaging

This study evaluated the effect of modified atmosphere packaging (MAP) in extending the shelf life of a fresh ewe’s cheese stored at 4 °C for 21 days. Three batches were prepared with 20, 30 or 50% CO₂ with N₂ as filler gas. MAP controlled well the microbial growth, and the best result was obtained with 50% CO₂. Pathogens were not detected in any sample. Softening of cheese was best reduced by 30% or 50% CO₂. The sensory characteristics of the cheeses markedly decreased during storage. Only the sample stored with 50% CO₂ obtained an overall score above the acceptability at 14 days.     

STUDY ON INTERACTION AMONG EXTRUSION-COOKING PROCESS VARIABLES AND ENZYME ACTIVITY: EVALUATION OF EXTRUDATE STRUCTURE

A blend of wheat flour (moisture content 11.61%) and different amounts of two commercial enzymes like GRINDAMYL (GA) amylase 1000 (0–0.1 g/kg) and GA protease 41 (0–1.0 g/kg) were extruded through a co-rotating twin-screw extruder.
The effects of barrel temperature (60–120C), dough moisture (20–36%), screw speed (100–400 rpm) and different amounts of enzymes on structure of extrudates (porosity and break strength) were studied using response surface methodology.
Results showed that the highest value of porosity (62.47%  ±  4.07) was obtained at the highest value of barrel temperature (120C) and at the largest amounts of GA protease 41 (1.0 g/kg) or GA amylase 1000 (0.1 g/kg). However, the simultaneous addition of large amounts of both enzymes caused a negative effect on expansion degree (porosity  <  30%). Large amounts of moisture dough and GA amylase 1000 resulted in a high value of break strength (25.7 N/mm²) and in stiff-textured extrudates .

PRACTICAL APPLICATIONS

This research could provide some information about the effects of and the interactions between extrusion parameters and enzyme activities, which are commonly used to produce bakery products, in order to improve the texture of extrudates processed at low barrel temperatures, i.e., 60C, for example, extrudates with thermolabile components like vitamins or extrudates with high lipid fraction like breakfast cereals, pet food, etc.