Nanocomposites and nanomaterials

Polysaccharide based microhydrogels synthesized using Steglich esterification
Nahorniak M.I., Vynnytska S.I., Stasiuk A.V., Dron I.A., Samaryk V.Ya.
Organic Chemistry Department, Lviv Polytechnic National University, 12, Stepan Bandera str., Lviv-79013, Ukraine. 
E-mail: minagorniak@gmail.com

Lately polysaccharides become more and more interesting object for scientist, as they own a big number of benefits, namely, they relate to renewable raw materials, are widespread in nature, have no toxity and no immunogenicity. Combining of such a unique properties with the idea of creation of biomedical application can reach a significant success.
To achieve this goal we propose to synthesize microhydrogels based on polysaccharides and N-derivatives of glutamic acid using Steglich reaction. The choice of this reaction is explained by the possibility of controlled production of non-peptidic chemical bond in very soft conditions [1].
The result of interaction is the formation of two products, namely branched and cross-linked polysaccharides. These products were separated using methanol sedimentation with the following characterization of their colloid-chemical properties. Both fractions formed in aqueous media self-stabilized dispersions. The size of the branched polysaccharide particles depends on the concentration, since at concentration of 0.06-0.08 wt % established the CMC, up to which the particle size is set nearly 200 nm and after 500-800 nm. The size of the cross-linked polysaccharide particles is set up to 4 µm.
The ability of obtained products to absorb hydrophobic biomedical preparation was investigated in terms of solubilization of dye Sudan III. Moreover, character of the solubilization curves confirmed the structure of obtained products. 
An important characteristic of biomedical application is the ability to interact with proteins of blood plasma. Therefore, was conducted gel electrophoresis with bovine serum albumin and found that cross-linked polysaccharide bent it in three times better than branched polysaccharide. The toxicology of obtained products showed that, in some cases, the percentage of cell survival from control group was higher. 

1.	Nagornyak M., Figurka N., Samaryk V., Varvarenko S., Ferens M., Oleksa V. Modification of Polysaccharides by N-Derivatives of Glutamic Acid Using Steglich Reaction // Chem.Chem.Technol.- 2016.-10.-P. 424-427.