Self-assembled vesicles of amphiphilic poly(dimethylsiloxane)-b-poly (ethylene glycol) copolymers as nanotanks for hydrophobic drugs

Polymeric nanovesicles self-assembled by amphiphilic block copolymers have attracted much attention in the biodelivery of hydrophobic drugs. In this paper, the amphiphilic copolymers of poly(dimethylsiloxane)-block-poly(ethylene glycol) (PDMS-b-PEG) were synthesized to fabricate polymeric nanovesicles in mixed solvent of THF and water. Dynamic light scattering (DLS) were used to monitor the assembling process of the block copolymers, and the aqueous nanovesicle solution could be obtained by a slow evaporation of THF. The vesicle size could be adjusted according to the volume ratio of water to THF and also the concentration of copolymers in the assembly. Higher water content in the mixed solvent produced smaller vesicles, while higher polymer concentration caused the formation of larger vesicles. The hydrophobic domain of the obtained nanovesicles could encapsulate hydrophobic drugs based on the hydrophobic interaction, in which the nanovesicles acted as water-soluble hydrophobic nanotanks. The drug encapsulation capability of these nanovesicles might exhibit a significant potential as drug nanocarriers in biodelivery system. (C) 2010 Elsevier B.V. All rights reserved.