Mixed micellar nanoparticles based on PCL-PEG-PPO-PEG-PCL pentablocks

In an attempt to assess the limitations of pure F-68 pluronic nanoparticles and make use of their benefits, the mixed micelles of F-68 with polycaprolactone (PCL) homopolymer, mono-methoxy poly (ethylene glycol)-block-PCL-block -mono-methoxy poly(ethylene glycol) triblock (mPEG-PCL-mPEG) and PCL-block-PEG-block-poly (propylene oxide)-block-PEG-block-PCL pentablock (PCL-PEG-PPO-PEG-PCL) copolymers were prepared separately. DSC studies of the mixed formulations together with loadings (using newly introduced parameters such as micelle encapsulation efficiency [MEE]), sizings, and release mechanism evaluations confirmed that the introduction of the synthesized pentablock copolymers, as a core-compatibilizer, in both pure and mixed micelles results to the multicomponent blend-like core with minimum order of chains. The compatibilized core using pentablocks can boost drug encapsulations, particle sizes, PDIs, and, finally, zero-order mono-mechanism release of loaded drug.