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Oxidative stress caused by an overproduction of reactive oxygen species (ROS) is the key factor in developing a variety of pathological conditions. Recently various nanomaterials have attracted growing interest as nanoantioxidants with ROS-regulating ability. Here, for the first time, we report on high antioxidant behavior (enzyme-like activity) of GdYVO4:Eu3+ nanoparticles (GdYVO NPs) revealed by spectroscopic methods both in cell-free and biological milieu using various ROS sensors. It was revealed that GdYVO NPs (d = 2 nm) effectively scavenge hydroxyl radicals · O H , superoxide anions O 2 · âˆ' , hydrogen peroxide H 2 O 2 , peroxyl radicals R O O · , and remarkably reduce the lipopolysaccharide-induced ROS generation in rat leukocytes. The antioxidant activity of GdYVO NPs is ascribed to high amount of V4+ and V3+ ions in the structure of the NPs and the reversible switching V 3 + â†" V 4 + and V 4 + â†" V 5 + vanadium oxidation states. [ABSTRACT FROM AUTHOR]

Introduction . Rare-earth orthovanadate nanoparticles (ReVO 4 :Eu 3+ , Re = Gd, Y or La) are promising agents for photodynamic therapy of cancer due to their modifiable redox properties. However, their toxicity limits their application. Objective . The aim of this research was to elucidate pro-eryptotic effects of GdVO 4 :Eu 3+ and LaVO 4 :Eu 3+ nanoparticles with identification of underlying mechanisms of eryptosis induction and to determine their pharmacological potential in eryptosis-related diseases. Methods . Blood samples ( n = 9) were incubated for 24 h with 0-10-20-40-80 mg l -1 GdVO 4 :Eu 3+ or LaVO 4 :Eu 3+ nanoparticles, washed and used to prepare erythrocyte suspensions to analyze the cell membrane scrambling (annexin-V-FITC staining), cell shrinkage (forward scatter signaling), reactive oxygen species (ROS) generation through 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) staining and intracellular Ca 2+ levels via FLUO4 AM staining by flow cytometry. Internalization of europium-enabled luminescent GdVO 4 :Eu 3+ and LaVO 4 :Eu 3+ nanoparticles was assessed by confocal laser scanning microscopy. Results. Both nanoparticles triggered eryptosis at concentrations of 80 mg l -1 . ROS-mediated mechanisms were not involved in rare-earth orthovanadate nanoparticles-induced eryptosis. Elevated cytosolic Ca 2+ concentrations were revealed even at subtoxic concentrations of nanoparticles. LaVO 4 :Eu 3+ nanoparticles increased intracellular calcium levels in a more pronounced way compared with GdVO 4 :Eu 3+ nanoparticles. Our data disclose that the small-sized (15 nm) GdVO 4 :Eu 3+ nanoparticles were internalized after a 24 h incubation, while the large-sized (∼30 nm) LaVO 4 :Eu 3+ nanoparticles were localized preferentially around erythrocytes. Conclusions. Both internalized GdVO 4 :Eu 3+ and non-internalized LaVO 4 :Eu 3+ nanoparticles (80 mg l -1 ) promote eryptosis of erythrocytes after a 24 h exposure in vitro via Ca 2+ signaling without involvement of oxidative stress. Eryptosis is a promising model for assessing nanotoxicity., (© 2023 IOP Publishing Ltd.)

Nanoparticles (NPs) have been reported to be promising enhancement agents for radiation therapy. The aim of the study was to assess the cytotoxicity of UV non-treated and UV pretreated GdYVO 4 :Eu 3+ nanoparticles against erythrocytes and leukocytes by detecting eryptosis and reactive oxygen species (ROS) generation. Levels of intracellular ROS in erythrocytes and leukocytes using a ROS-sensitive dye 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA), as well as eryptosis rate utilizing annexin V staining, following direct exposure to UV-activated and nonactivated NPs were detected by flow cytometry. Blood cells were collected from 9 intact WAG rats. Neither the UV light-untreated GdYVO 4 :Eu 3+ NPs nor the treated ones promoted eryptosis and ROS generation in erythrocytes. Low concentrations of UV light-untreated NPs did not induce oxidative stress in leukocytes, evidenced by unaffected intracellular ROS levels. UV light treatment grants prooxidant properties to NPs, confirmed by NP-induced ROS overproduction in leukocytes. High concentrations of both UV light-treated and untreated NPs altered the redox state of leukocytes. UV light treatment imparts prooxidant properties to GdYVO 4 :Eu 3+ NPs, making them promising radiosensitizing agents in cancer radiation therapy., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The safety of food additives E407 and E407a has raised concerns in the scientific community. Thus, this study aims to assess the local and systemic toxic effects of the common food additive E407a in rats orally exposed to it for two weeks. Complex evaluations of the effects of semi-refined carrageenan (E407a) on rats upon oral exposure were performed. Local effects of E407a on the intestine were analyzed using routine histological stains and CD68 immunostaining. Furthermore, circulating levels of inflammatory markers were assessed. A fluorescent probe O1O (2- (2'-OH-phenyl)-5-phenyl-1,3-oxazole) was used for evaluating the state of leukocyte cell membranes. Cell death modes of leukocytes were analyzed by flow cytometry using Annexin V and 7-aminoactinomycin D staining. Oral administration of the common food additive E407a was found to be associated with altered small and large intestinal morphology, infiltration of the lamina propria in the small intestine with macrophages (CD68 + cells), high systemic levels of inflammation markers, and changes in the lipid order of the phospholipid bilayer in the cell membranes of leukocytes, alongside the activation of their apoptosis. Our findings suggest that oral exposure to E407a through rats results in the development of intestinal inflammation.

Background: Concerns about the biosafety of the common food additive E407a have been raised. It has been demonstrated to induce intestinal inflammation, accompanied by activation of apoptosis, upon oral exposure. Thus, it is of interest to investigate how E407a affects eryptosis, a suicidal cell death mode of red blood cells., Objective: To evaluate the effects of semi-refined carrageenan (E407a) on eryptosis., Methods: Flow cytometry was employed to assess eryptosis in blood exposed to various concentrations of E407a (0 g/L, 1 g/L, 5 g/L, and 10 g/L) during incubation for 24 h by analyzing phosphatidylserine externalization in erythrocytes using annexin V staining and via evaluating reactive oxygen species (ROS) generation using 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA). In addition, the eryptosis indices mentioned above were determined in rats orally administered E407a at a dose of 140 mg/kg weight for 2 weeks. Confocal scanning laser microscopy was performed to visualize cell membrane scrambling., Results: Oral intake of E407a for 2 weeks by rats was not associated with membrane scrambling in erythrocytes. However, ROS overproduction was observed. Meanwhile, incubation of blood with various concentrations of semi-refined carrageenan resulted in a dose-dependent promotion of eryptosis, evidenced by the enhanced percentage of annexin V-positive erythrocytes and higher mean fluorescence intensity (MFI) values of annexin V-FITC in all erythrocytes. The highest concentration of E407a promotes a statistically significant increase in ROS generation in erythrocytes, suggesting the role of ROS-mediated induction of eryptosis in this case., Conclusion: Incubation of blood with the food additive E407a leads to the activation of eryptosis in a dose-dependent manner. ROS-mediated mechanisms are partially responsible for E407a-induced eryptosis., (© 2021. Springer-Verlag GmbH Austria, ein Teil von Springer Nature.)

Clinical application of a large variety of biomaterials is limited by the imperfections in storage technology. Perspective approaches utilizing low-temperature storage are especially challenging for multicellular structures, such as tissues, organs, and bioengineered constructs. Placenta, as a temporary organ, is a widely available unique biological material, being among the most promising sources of various cells and tissues for clinical and experimental use in regenerative medicine and tissue engineering. The aim of this study was to analyse the mechanisms of cryoinjuries in different placental tissues and bioengineered constructs as well as to support the viability after low temperature storage, which would contribute to development of efficient biobanking technologies. This study shows that specificity of cryodamage depends on the structure of the studied object, intercellular bonds, as well as interaction of its components with cryoprotective agents. Remarkably, it was possible to efficiently isolate cells after thawing from all of the studied tissues. While the outcome was lower in comparison to the native non-frozen samples, the phenotype and expression levels of pluripotency genes remained unaffected. Further progress in eliminating of recrystallization processes during thawing would significantly improve biobanking technologies for multicellular constructs and tissues., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Placental structures, capable to persist in a genetically foreign organism, are a natural model of allogeneic engraftment carrying a number of distinctive properties. In this review, the main features of the placenta and its derivatives such as structure, cellular composition, immunological and endocrine aspects, and the ability to invasion and deportation are discussed. These features are considered from a perspective that determines the placental material as a unique source for regenerative cell therapies and a lesson for immunological tolerance. A historical overview of clinical applications of placental extracts, cells, and tissue components is described. Empirically accumulated data are summarized and compared with modern research. Furthermore, we define scopes and outlooks of application of placental cells and tissues in the rapidly progressing field of regenerative medicine.

Background: Successful implementation of rapidly advancing regenerative medicine approaches has led to high demand for readily available cellular suspensions. In particular, multipotent stromal cells (MSCs) of placental origin have shown therapeutic efficiency in the treatment of numerous pathologies of varied etiology. Up to now, cryopreservation is the only effective way to preserve the viability and unique properties of such cells in the long term. However, practical biobanking is often associated with repeated temperature fluctuations or interruption of a cold chain due to various technical, transportation, and stocking events. While biochemical processes are expected to be suspended during cryopreservation, such temperature fluctuations may lead to accumulation of stress as well as to periodic release of water fractions in the samples, possibly leading to damage during long-term storage., Methods: In this study, we performed a comprehensive analysis of changes in cell survival, vital parameters, and differentiation potential, as well as transgene expression of placental MSCs after temperature fluctuations within the liquid nitrogen steam storage, mimicking long-term preservation in practical biobanking, transportation, and temporal storage., Results: It was shown that viability and metabolic parameters of placental MSCs did not significantly differ after temperature fluctuations in the range from -196 °C to -100 °C in less than 20 cycles in comparison to constant temperature storage. However, increasing the temperature range to -80 °C as well as increasing the number of cycles leads to significant lowering of these parameters after thawing. The number of apoptotic changes increases depending on the number of cycles of temperature fluctuations. Besides, adhesive properties of the cells after thawing are significantly compromised in the samples subjected to temperature fluctuations during storage. Differentiation potential of placental MSCs was not compromised after cryopreservation with constant end temperatures or with temperature fluctuations. However, regulation of various genes after cryopreservation procedures significantly varies. Interestingly, transgene expression was not compromised in any of the studied samples., Conclusions: Alterations in structural and functional parameters of placental MSCs after long-term preservation should be considered in practical biobanking due to potential temperature fluctuations in samples. At the same time, differentiation potential and transgene expression are not compromised during studied storage conditions, while variation in gene regulation is observed.

Human placenta is a highly perspective source of multipotent stromal cells (MSCs) both for the purposes of patient specific auto-banking and allogeneic application in regenerative medicine. Implementation of new GMP standards into clinical practice enforces the search for relevant methods of cryopreservation and short-term hypothermic storage of placental MSCs. In this paper we analyze the effect of different temperature regimes and individual components of cryoprotective media on viability, metabolic and culture properties of placental MSCs. We demonstrate (I) the possibility of short-term hypothermic storage of these cells; (II) determine DMSO and propanediol as the most appropriate cryoprotective agents; (III) show the possibility of application of volume expanders (plasma substituting solutions based on dextran or polyvinylpyrrolidone); (IV) reveal the priority of ionic composition over the serum content in cryopreservation media; (V) determine a cooling rate of 1°C/min down to -40°C followed by immersion into liquid nitrogen as the optimal cryopreservation regime for this type of cells. This study demonstrates perspectives for creation of new defined cryopreservation methods towards GMP standards.