Metal-free organic catalyst for synthesis of low dispersity poly(ethylene glycol-block-polylactide) copolymers with well-defined structure

Ring-opening polymerization of lactide was performed in the presence of 1,8-diazabicyclo[5.4.0]undec-5-ene as an organic catalyst and polyethylene glycol as a hydroxyl-containing macroinitiator. A series of amphiphilic poly(ethylene glycol-block-polylactide) copolymers with a low dispersity (PDI = 1.1), different stereoregularity and length of the polylactide block was obtained. Nanoparticles with a diameter of 20-25 nm were produced from selected polymers and were studied by in vitro cytotoxicity tests.