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New composite nanoparticles for biomedical applications have been manufactured. The particles consist of an anisomeric magnetite core coated with arabinogalactan and are functionalized with cameras for As-14 ascites cells (Ehrlich carcinoma). The binding of ascitic Ehrlich carcinoma cells to magnetic nanoparticles was evaluated using fluorescence microscopy.

New prospects for the applications of single-stranded DNA and RNA as therapeutic agents have been discovered in the recent years. Aptamers are the oligonucleotides that bind to their targets with high affinity and specificity due to the well-defined tertiary structures and spatial charge distribution. Aptamers can be selected for any molecules, virus particles, bacteria, cells, and tissues. They have a wide range of applications from target identification to drug delivery. Aptamers themselves can affect various cell functions by affecting certain proteins and receptors. Here, we present the technique for selecting aptamers with antitumor activity in cancer cell cultures and identifying their target proteins by mass spectrometry analysis. The evolved aptamers showed the following antitumor properties: AS-14 (Kd = 3.8 nM) induced apoptosis (phosphatidylserine translocation determined with Annexin V Alexa Fluor 488) and AS-9 (Kd = 0.75 nM) stopped proliferation (as determined with CellTrace™ Far Red DDAO-SE) in the culture of Ehrlich ascites adenocarcinoma cells. Using high performance liquid chromatography and high resolution tandem mass spectrometry, we have identified the proteins affected by the AS-14 and AS-9 aptamers. One of the most likely targets for AS-14 was filamin A, which is involved in metastasis formation, tumor development, and cell proliferation. According to mass spectrometry data, the AS-9 aptamer influences the α-subunit of mitochondrial ATP synthase, the key component of mitochondrial oxidative phosphorylation, stimulation of which leads to tumor growth suppression. Thus, mass spectrometry data confirmed the results of the experiments on cell cultures showing that the aptamer binding to specific protein targets causes apoptosis and stops proliferation of cancer cells. However, the mechanisms of action of aptamers in vitro and in vivo are not clear enough and still need to be determined. Our study opens up new possibilities for creation of non-toxic drugs based on DNA aptamers for targeted anticancer therapy.

The effects of cisplatin on [Ca 2+ ] in , pH in , NAD(P)H level, and lymphocyte membrane microviscosity were studied in mice with Ehrlich ascitic carcinoma. The level of free [Ca 2+ ] in in lymphocytes from mice with Ehrlich ascitic carcinoma was 4-fold reduced compared to that in intact animals on day 13 of tumor development, while [H + ] in level was elevated. Cisplatin caused no changes in the level of free Ca2+, but reduced cytosol acidification. Lymphocyte membrane fluidity in mice with tumors was increased in the lipid bilayer and in the proteinlipid contact zone and did not depend on cisplatin treatment. The level of NAD(P)H was low in mice with tumors, but increased sharply after cisplatin treatment. It seems that functional activity of lymphocytes decreased at the stage of well-developed tumor, which promoted inhibition of the lymphocyte defense properties. Cisplatin did not modify the structure and functions of lymphocytes and presumably even improved their energy status.