Circulating microparticles: square the circle

Background: The present review summarizes current knowledge about microparticles (MPs) and provides a systematic overview of last 20 years of research on circulating MPs, with particular focus on their clinical relevance. Results: MPs are a heterogeneous population of cell-derived vesicles, with sizes ranging between 50 and 1000 nm. MPs are capable of transferring peptides, proteins, lipid components, microRNA, mRNA, and DNA from one cell to another without direct cell-to-cell contact. Growing evidence suggests that MPs present in peripheral blood and body fluids contribute to the development and progression of cancer, and are of pathophysiological relevance for autoimmune, inflammatory, infectious, cardiovascular, hematological, and other diseases. MPs have large diagnostic potential as biomarkers; however, due to current technological limitations in purification of MPs and an absence of standardized methods of MP detection, challenges remain in validating the potential of MPs as a non-invasive and early diagnostic platform. Conclusions: Improvements in the effective deciphering of MP molecular signatures will be critical not only for diagnostics, but also for the evaluation of treatment regimens and predicting disease outcomes

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

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In previous experiments the self-dependent antitumor effect of magnetite nanoparticles (NPs) injected in peritumoral area in form of magnetic fluid (MF) was shown. Elucidation of the mechanisms of this phenomenon is of theoretical and practical interest. The aim of the study was to investigate the cellular and ultrastructural changes in the tissue tumors regressed under the influence of magnetite NPs, as well as the composition of the cells of the immune system in the peritumoral area. Materials and methods: The study was carried on white male rats, 180–200 g, with transplanted sarcoma 45 (59) or Pliss lymphosarcoma (50). Special antitumor agents were not used. Magnetite NPs (10 ± 2 nm) were applied in the form of the water-based MF. Original MF (20 kA/m) was diluted with saline in different degree and was injected into peritumoral zone along the tumor borders at a distance of 1.5 cm twice a week in a volume of 0.4–0.9 ml (depending on the animal weight) within 3 weeks. Special anti-tumor agents were not used. At the end of the experiments fragments of the tumor and surrounding tissue were taken for research. The study of changes in the tumor and peritumoral area were performed by the methods of cytology, histology, histochemistry, electron microscopy (microscope JEOL JEM-1011, Japan), flow cytometry, X-ray fluorescence spectroscopy (spectrometer M4 Tornado Bruker). Results: At a dilution of the original MF in 30 times the treatment was effective in 75% of animals. Complete and partial (more than 2-fold) tumor regression was observed in 2/3 cases. In rats with Pliss lymphosarcoma tumor regression on 70–100% has been reported in 20–40% cases. The results of microscopic examination of sarcoma 45 with partial regression showed significant changes in their immune microenvironment compared with the cases of progressive tumor growth (p < 0.05–0.01). This was expressed in the increase in the number of lymphocytes and plasmacytes (respectively, in 12 and 2.5 fold), and in the appearance of macrophages and basophils that were missing in tumors with progressive growth. The results of flow cytometry of tissue from the tumor as well as from peritumoral zone indicate the predominance of plasmacytes in the case of inhibition of tumor growth and increasing the proportion of mature T lymphocytes in the cases of tumor regression (more than 1.5 times, p < 0.05). By electron microscopy, it was shown that in the cases of efficiency of the MF in addition to necrosis, observed also in growing tumors, such types of cell death were marked as apoptosis and autophagy. Numerous signs of activation of cell–cell interactions involved cells of the immune system were revealed. Different groups of 2–4 contacting cells (macrophages, lymphocytes, plasmacytes, mast cells, tumor-associated fibroblasts and neutrophils in various combinations) with signs of metabolic activity were marked. X-ray fluorescence spectroscopy preliminary results in rats with Pliss lymphosarcoma regression indicated dense arrangement of magnetite NPs and their aggregates in the peritumoral area and their practical absence in tumor. Conclusion: The study results reflect the changes in the immune microenvironment of experimental tumors under effective action of magnetite NPs and indicate significant activation of local immune processes caused by these factors