TY - JOUR AU - Dyubko, T. S. AU - Pivovarenko, V. G. AU - Chekanova, V. V. AU - Hvozdiuk, Ya. V. AU - Pakhomova, Yu. S. AU - Kompaniets, A. M. AU - Tatarets, A. L. PY - 2020/12/29 Y2 - 2024/03/28 TI - Study of polyvinyl alcohols (9 and 31 kDa) aggregation in aqueous solutions by fluorescent probing JF - Biophysical Bulletin JA - Bioph. Bull. VL - IS - 44 SE - Biophysics of complex systems DO - 10.26565/2075-3810-2020-44-01 UR - https://periodicals.karazin.ua/biophysvisnyk/article/view/16314 SP - 7-17 AB - Background: When developing low-temperature cell storage methods, a serious problem is recrystallization, which leads to cell damage during thawing. Previous studies have shown the promising use of polyvinyl alcohol (PVA) as an inhibitor of recrystallization. But the mechanisms of protective action of PVA are not finally clarified. So, it is not known what structural features contribute to implementation of PVA antirecrystallization properties in the cryoprotective concentration range.Objectives: Establishing the peculiarities of structuring PVA molecules in aqueous solutions using the fluorescent probe.Materials and Methods: Aqueous solutions of 0.1–5% (wt.%) PVA with molecular mass (m.m.) of 9 and 31 kDa) were studied. Fluorescence probe method, photometry, stalagmometry, and molecular modeling were used.Results: Using the 3-hydroxy-4¢-(N,N-dimethylamino)flavones  (FME) fluorescent probe it was found that in 0.1–5% of PVA (m.m. 9 and 31 kDa) aqueous solutions the structural organization of polymers changes with formation of different in size and structure of local hydrophobic regions. In PVA solutions, m.m. 9 kDa micelles with smaller cavities are formed in which FME is densely surrounded by polymer segments. In the case of PVA m.m. 31 kDa, it forms micelles with smaller cavities surrounded by polymer segments. PVA m.m. 31 kDa forms micelles with larger in size and more hydrophilic cavities. If the content is more than 3%, PVA m.m. 31 kDa aggregates are partially destroyed, which may be the result of increased water content. Under these conditions, PVA m.m. 9 kDa micelles are enlarged. as a result of aggregation. According to molecular modeling data, PVA is able to form strong hydrogen-linked complexes with the surface of ice nanocrystals. Such complex, having a hydrophobic surface, can depolarize water molecules, thus slowing down further growth of ice crystals.Conclusions: Changes in the structural organization, which may affect the recrystallization properties, have been found in water solutions of PVA. The mechanism of implementation of polymer anticrystallization activity has been suggested. The possible role of structure and supramolecular organization of PVA in aqueous solutions in understanding the mechanisms of depressing recrystallization during freeze-thawing of cells is discussed. ER -