Nanoscale structures of dextran esters

Multifunctional dextran esters with varying degrees of substitution by furoyl-, pyroglutamyl-, propyl-, and acetyl moieties are able to self-assemble into regular nanospheres during a dialysis process. That means a controlled and slow exchange of the organic solvent N,N-dimethylacetamide against water results in formation of biopolymer based nanoparticles with a size in the range of 90-520 nm. The size of the nanospheres depends on the ratio of the introduced functional groups, the molecular weight of the polymers, and the preparation conditions. A functionalization of a degree of substitution of at least 2.0 is necessary to get semisynthetic dextran derivatives that are able to form these nanoparticles. According to the encapsulation of the fluorescence probe pyrene, hydrophobic domains were verified inside the dextran ester nanoparticle. (c) 2007 Published by Elsevier Ltd.