ABSTRACT
The properties of polymer brushes based on three macromonomers were investigated in aqueous and organic solutions. Methacrylic monomers with different compositions of the oligo(oxyalkylene) substituents and arrangements of the oligo(ethylene glycol) and oligo(propylene glycol) blocks were used for the synthesis of polymers. There were methoxy [oligo(ethylene glycol)10.3-block-oligo(propylene glycol)4.7] methacrylate, methoxy [oligo(propylene glycol)8.3-block-oligo(ethylene glycol)6.6] methacrylate, and methoxy oligo(propylene glycol)4.2 methacrylate. Molecular brushes were investigated by the methods of molecular hydrodynamics and optics in dilute solutions in acetonitrile, chloroform, and water. The peculiarities of behavior of poly[oligo(oxyalkylene) methacrylates] in aqueous solutions and water-toluene systems have been found; in particular, the solubility of the polymers in water and organic solvents, the polymers equilibrium distribution between the phases, and the surface activity in the water-toluene system have been established. The thermo-responsibility in aqueous solutions and values of a critical concentration of micelle formation were shown. Depending on the arrangement of blocks in the side chains of molecular brushes, they are characterized by different intramolecular density.
ABSTRACT
The synthesis of two new copolymer conjugates of methoxyoligo(ethylene glycol)methacrylate MPEGMA and betulin methacrylate BM was developed via RAFT polymerization. The molar content of BM units was equal to 9-10 and 13-16 mol%, respectively (HPLC, 1H and 13C NMR); molar weights were equal to 75000-115000. CeO2 NPs as a component of the hybrid material were synthesized for the preparation of the composition with copolymer conjugates of MPEGMA and BM. We showed a significant increase in G6PDH and GR activities by 21-51% and 9-132%, respectively, which was due to the increase in NADPH concentration under the action of copolymers in vitro. The actions of copolymers and CeO2 NPs combination were stronger than those of the individual components: the SOD activity increased by more than 30%, the catalase activity increased dose-dependently from 13 to 45%, and the GR activity increased to 49%. The maximum increase in enzyme activity was observed for the G6PDH from 54% to 151%. The MDA level dose-dependently increased by 3-15% under the action of copolymers compared with the control, and dose-dependently decreased by 3-12% in samples containing CeO2 NPs only. CeO2 NP-copolymer compositions can be used for the design of new biomimetic medical products with controlled antioxidant properties.
