Organocatalytic synthesis of temperature-sensitive degradable PNiPAAm-b-PTMC block copolymers and micellar characterizations

Amphiphilic PNiPAAm-b-PTMC were synthesized by ring-opening polymerization of trimethylene carbonate (TMC) initiated by hydroxyl-terminated poly(N-isopropylacrylamide) (PNiPAAm) as the macroinitiator with the organocatalyst 1,5,7-triazabicyclo-[4.4.0]dec-5-ene (TBD). PNiPAAm-b-PTMC solutions had lower critical solution temperature (LCST) that depended on polymer composition and the solution media. The block copolymers form micelles in the aqueous phase with core-shell structure. Transmission electron microscopy analysis of micelle morphology revealed a spherical structure. Observations and determinations show high drug entrapment efficiency and drug-loading content for these drug micelles.