Light-responsive and biodegradable block polymer synthesized by RAFT polymerization and its potential drug carrier properties

Abstract

A well-defined, light-responsive copolymer poly(spiropyrane)-block-poly(ethylene glycol) (PSP-b-PEG) was synthesized by RAFT polymerization. The final copolymer can selfassembled into spherical micelles with a hydrophilic PEG corona and a hydrophobic spiropyrane core in aqueous solution. Moreover, the properties of micelles in aqueous solution were detected by fluorescence spectroscopy, UV?vis spectroscopy, dynamic light scattering (DLS), and scanning electron microscope (SEM). Model drug Nile Red was then encapsulated into the micelles and its light-controlled release was studied. In addition, an MTT assay provided the evidence for the low cell cytotoxicity of PSP-b-PEG micelles. The results demonstrate that the spherical micelles of PSP-b-PEG possess a potential application in smart drug delivery.