Synthesis of hydroxyl-capped comb-like poly(ethylene glycol) to develop shell cross-linkable micelles

A novel hydroxyl-capped comb-like poly[poly(ethylene glycol) methacrylate] (PPEGMA) was prepared via atom transfer radical polymerization (ATRP) of α-methylacryloyl-ω-hydroxyl-poly(ethylene glycol) at ambient temperature. The polymerization kinetics of the block copolymer was studied by gel permeation chromatography (GPC) and 1H NMR. It is of interest to find the well-defined comb-like PEG can associate into micelles, which have hydrophilic PEG shell end-capped by hydroxyl groups. The hydroxyl in the shell were further cross-linked by divinyl sulfone (DVS), which could couple with two capped-end hydroxyl groups. The XPS, TEM, AFM and laser scattering particle size distribution analyzer results revealed that reactive micelles could be cross-linked by DVS. The reactive, cross-linkable micelles with PEG shell may have great potential as new drug carrier and nanoreactor, etc.