Biocompatible micelles based on comb-like PEG derivates: formation, characterization, and photo-responsiveness.

A novel comb-like derivative CPEG-g-DNQ was prepared by incorporating light responsive 2-diazo-1,2-naphthoquinone (DNQ) groups into the structure of comb-like poly(ethylene glycol) (CPEG). DLS and TEM results showed that CPEG-g-DNQ self-assembled into spherical micelles with an average size of about 135 nm in water. Upon exposure to light, the micelles could be disrupted because of the conversion of hydrophobic DNQ to hydrophilic 3-indenecarboylic acid. Additionally, hydrophobic coumarin 102 was successfully loaded into the micelles and photo-induced ON-OFF release was demonstrated by fluorescence spectroscopy. MTT assay revealed that the micelles are biocompatible. These photo-responsive micelles might have great potential for controlled release of hydrophobic drugs.