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Anemia is one of the most common disorders in the world generated by multiple causes. Despite a good understanding of the causes of anemia, there is still uncertainty about how best this should be investigated, prevented and managed. This reflects the limitations of laboratory tests, as well as the poor understanding of the complex physiological mechanisms. A better understanding of the nature of anemia and the changes in erythrocytes may provide new strategies to benefits of patients. In this study, it was identified by flow cytometric and SEM analysis, the morphological changes of forms that deviate from the classical discoid shape, which had an increase in the mean fluorescence intensity of calcein (erythrocyte viability measured by the level of intracellular esterase activity with the Calcein-AM method). The results obtained for RBCs from the patients with different types of anemia did not demonstrate a massive phosphatidylserine externalization measurable with Annexin-V-FITC compared to the values for normal erythrocytes. The present study provides that flow cytometric analysis can be a quick and efficient method for diagnosing in haematological diseases and monitoring and in the medical biotechnology industry in order to develop drugs to treat anemia.

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The use of nanoparticles for biological and medical applications has rapidly increased and the potential for human and ecological toxicity is a growing area of investigation. For assessing cytotoxicity of nanoparticles we developed a new experimental cell system based on the use of nucleated erythrocytes (RBCs) from fish and batrachians, which are directly exposed to pollutants or nanoparticles absorbed by different ways and we have evaluated the toxic effects by flow cytometric analysis. The two modes of cell death (apoptosis and necrosis) differ fundamentally in their morphology, biochemistry and biological relevance. We and others have recently shown that programmed cell death of nucleated erythrocytes is related to an apoptotic mechanism. The toxicological analysis were performed comparatively on porphyrin base or metalloporphyrin and for each porphyrin bare derivative on two correspondent porphyrin-silica-hybrid nanomaterials obtained by one step acid catalysis and by two steps acid-base catalysis. To evaluate cell-nanoparticles interactions, nucleated RBCs were exposed to different concentrations of nanocomposites and analyzed by flow cytometry, after 24h incubation endpoints for morphological changes (FSC/SSC), apoptosis/necrosis analysis (FITC-annexin-V labeling/PI) and viability (using calcein-AM method). The investigation showed that the type of cellular death of nucleated erythrocytes is related to an apoptotic mechanism and that flow cytometric analysis of nucleated RBCs viability and cell death discrimination could provide a rapid and accurate analytical tool for evaluating in vitro the biological responses towards of nanoparticles for environmental protection. Nucleated erythrocytes can be a new experimental cellular model easy to use, with no costs for culture and for maintaining in the culture. The results reported in the present study indicate that our new flow cytometric protocols can be used to create dose-response curves which allow us to determine EC50 for toxicity or ecotoxicity tests. It is also generally applicable for identifying harmful effects associated with general antropic impact for the aquatic environment and for its biomonitoring.

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Polycythemia vera (PV) is characterized by an absolute increase in the red blood cell mass, but the mechanisms are not completely understood. In this study, we identified by flow cytometric analysis morphological forms that deviate from the classical discoid shape, who had level. Measurement of glycoconjugate sialylation using lectines demonstrates but which is close to normal after treatment and an increased percentage of cells with active caspase-8 and -3 compared to normal RBCs, showing that the organism tries to restore the apoptotic mechanism for maintaining the normal hematocrit. may contribute elucidation of the mechanism this diseasea more viability determined by Calcein-AM method and a normal phosphatidylserine exposure a low degree of sialilation of membrane glycoconjugates of Polycythemia vera RBCs Our observations for understanding the survival of RBCs in Polycythemia vera and may also participate in elucidation of the mechanism this diseasein pathogenesis of this disease. © 2011 Vasile Goldis University Press.

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The human activities have a negative impact to the environment, consisting in the water contamination with toxic products, heavy metals or with xenobiotic substances. Manufactured nanomaterials (nanoparticles, nanotubes, nanosheets and nanowires) have recent applications in drug delivery, medical devices, cosmetics, chemical catalysts, optoelectronics, electronics and magnetics. Some nanomaterials have been found to be toxic to humans and other organisms either upon contact or after persistent environmental exposure. In present, the measurements of the pollution degree are made with two methods: phisyco-chemical methods and ecotoxicological test (bioassay or environmental biosensors). Our results indicate that flow cytometric analysis of nucleated red blood cells viability using calcein-AM and cell death discrimination could provide a rapid and accurate experimental cellular model for effectively screening and evaluating biological responses for in vitro nanotoxicology and can be used in ecotoxicology as bioassays for the ecological monitoring of aquatic environment. In the some time, our results indicate that the use of nucleated erythocytes could be potentially useful for the development of rapid and low cost safety tests to assess fisheries product quality. © 2011 Vasile Goldis University Press.

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Over the past 30 years greater attention has been focused on development of controlled and sustained drug delivery systems. The goal in designing these systenis is to reduce the frequency of dosing or to increase effectiveness of the drug by localization at die site of the action, decreasing the dose required or providing uniform drug delivery. Polymers have historically been the keys to the great majority in drug delivery systems. Hydrogels preformed by chemical or physical cross-linking form three dimensional, hydrophilic, polymeric networks capable of imbibing large amounts of water or biological fluid. In order to obtain biocompatible hydrogels chitosan, hyaluronic acid extracted from swine vitreous, gelatin, carrageenan etc were used. To improve the qualities of pellicles it was used physic cross-linking agents (UV and thermic radiations) and/or ionic substances (sodium citrate, calcium chloride). The obtained hydrogels were tested for swollen capacity (in PBS at 20 degrees C) and in vitro degradation (in PBS at 37 degrees C). Preliminary studies for entrapment of protease inhibitor in hydrogel were done.