Formation of nanoparticles in aqueous solution from poly(ε-caprolactone)–poly(ethylene glycol)–poly(ε-caprolactone)

The amphiphilic triblock copolymer of poly(ε-caprolactone)-b-poly(ethylene glycol)-b- poly(ε-caprolactone) (PCL–PEG–PCL) was prepared by ring opening polymerization of PEG and ε-caprolactone in the presence of stannous 2-ethyl hexanoate (Sn(Oct)2) as catalyst. The structure of triblock copolymer was characterized by proton nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The polymeric nanoparticles were prepared in aqueous solution by a co-solvent precipitation technique at room temperature. Nanoparticles were formed from the amphiphilic triblock copolymer, and the effect of organic solvent water-miscibility on the size of nanoparticles was also investigated. Polymeric nanoparticles were measured by dynamic light scattering (DLS), with sizes in the range of 70–90 nm and narrow polydispersity. Additionally, the toxicities of polymeric micelles were evaluated by MTT assay. These results confirmed low toxic polymeric micelles and suggest that the polymeric micelles hold a potential for anticancer drug delivery