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Glioblastoma is the most common malignant tumor of the brain, but its treatment outcomes can be improved by new therapeutic techniques using biocompatible materials. Utilizing controllable alkaline de-esterification we obtained pectin preparation with 27.4% esterification degree and used it for bio-artificial matrix production. We discovered optimal gelation conditions in the presence of Ca 2+ by the analysis of visco-elastic properties of the gels and produced a series of biomaterials in hydrogel forms. Hydrogels based on low-esterified pectin significantly slow down the metabolism of C6 glioma cells and neural stem cells (NSCs) and slightly decrease the viability of the C6 glioma, but not of NSCs. This happens due to a decrease in cell proliferation rate, while apoptosis degrees remain stable or negligibly decrease. We created a set of pectin hydrogels supplemented with different ratios of two ECM proteins-collagens I and IV. We have shown that the formation of cell processes in glioma C6 can be regulated by varying the ratio of two ECM proteins in gels used for 3D cell cultivation. Thus, composite matrix materials obtained can be used for modeling brain tumor invasion. The results presented suggest that modified pectins supplemented with two collagen types may serve as prospective biomaterials for glioblastoma treatment due to their ability to regulate glioma cell dynamics., (© 2020 Elsevier Inc. All rights reserved.)

Animals with deformed shells and microalgal invasion have been identified in the natural population of the horse mussel species Modiolus kurilensis of Peter the Great Bay in the Sea of Japan. The haemolymph is initially infested with algae, followed by the rectum, siphons, mantles and gonads located in the posterior body areas. Mantles, which are primarily exposed to light, are major depots for algae. The microscopic analysis of algal cells has revealed the absence of flagella and pyrenoids, the presence of single chloroplast, and reproduction by autosporulation, with dispores prevailing over tetraspores. These results, together with the nearly complete sequence analysis of small subunit (SSU) 18S rDNA (1728bp), have confirmed that these cells are Coccomyxa parasitica. A newly developed method of isolating microalgae from mollusk tissues has facilitated the continuous pure - probably axenic - culture of C. parasitica, thereby providing a description of the time course of each life stage. Histological analyses have revealed significant haemocyte infiltration into the mantles, gonads, kidneys and digestive gland tissues infested with microalgae and the gill tissues, in which the intruder was not identified. Algal encapsulation with major focal areas of fibrosis and amorphic necrosis has been revealed in these infested organs. The spaces between the gonad follicles and digestive gland tubules were significantly widened as these areas were filled with a mass of algae and phagocytic haemocytes, showing acini with a thickened basement membrane. The mantles and kidneys of Modiolus displayed significant morphological deviations of different cells in epithelial, connective and muscle tissues, resulting in the dysfunction of the infested organs. Therefore, C. parasitica, which reproduces in the culture, regardless of the host, is a facultative parasite, causing major pathological alterations, such as anomalous histomorphological patterns and infested organ dysfunctions., (Copyright © 2016 Elsevier Inc. All rights reserved.)