Polymeric nano-micelles using poly(ethylene glycol) and poly(trimethylene carbonate) diblock copolymers as a drug carrier

The polymerization of trimethylene carbonate (TMC) in the presence of HCl·Et2O via activated monomer mechanism was performed to synthesize diblock copolymers composed of methoxy poly(ethylene glycol) (MPEG) and poly(trimethylene carbonate) (PTMC). The obtained PTMCs had molecular weights close to the theoretical values calculated from the TMC to MPEG molar ratios and exhibited monomodal GPC curves. We successfully prepared MPEG and PTMC diblock copolymers by activated monomer mechanism. The micellar characterization of MPEG–PTMC diblock copolymers in an aqueous phase was carried out by using NMR, dynamic light scattering, AFM and fluorescence techniques. The diblock copolymers formed micelles with a critical micelle concentration (CMC) ranging 1.76 × 10−3 to 0.79 × 10−3 mg/mL, depended on the hydrophobic block lengths of MPEG–PTMC copolymers. The diameters of micelles, measured by dynamic light scattering, were 150–360 nm. Most micelles exhibited a spherical shape in AFM.