Direct and effective preparation of core-shell PCL/PEG nanoparticles based on shell insertion strategy by using coaxial electrospray

Abstract

It is of great significance to efficiently prepare core-shell nanoparticles. In this study, we directly and efficiently prepared core-shell structured PCL/PEG nanoparticles based on shell insertion strategy by using coaxial electrospray. The key points to ensure the success of this new strategy include: the preparation of PCL particles with size less than 100 nm which worked as core structure; the insertion of PEG into PCL surface which worked as shell structure. We directly fabricated PCL particles with size less than 100 nm by using shell evaporation coaxial electrospray method. It means that PCL nanoparticles could be prepared and used as core structure through coaxial electrospray method. PEG solution worked as shell layer, PCL solution worked as core layer, PCL/PEG core shell structured microparticles were obtained through coaxial electrospray technique. Because of the solvent diffusion during the coaxial electrospray process, PEG could insert into PCL when TFE was used as the solvent of both core and shell layer. Then, after removing uninserted PEG, PCL/PEG nanoparticles with core-shell structure were fabricated successfully. The core-shell structured nanoparticles were stored at 4 °C and were stable without changing size for at least 7 days. This method can easily prepare core-shell structured nanoparticle with different size by changing the injection speed of PCL solution.