Emulsion preparation for novel micro-porous polymeric hemi-shells

Abstract

A modified oil-in-water (O/W) emulsion process was developed to produce novel micro-porous hemi-spherical polycaprolactone (PCL) micro-particles called "hemi-shells". By addition of a porogen such as sodium bicarbonate (NaHCO3) into the PCL-dichloromethane (DCM) oil phase and emulsification in an acidic polyvinyl alcohol (PVA) aqueous phase, micro-porous hemi-shells formed as solvent evaporated. CO2 gas evolution from the porogen created particles with an externally micro-porous shell and a large internal cavity. The hemi-shells were characterized by SEM and optical microscopy. The number-average particle yield in the 50-200 µm range was 84%. The number-average hemi-shell yield in the same size range was 41%. These novel micro-particles have potential applications in tissue engineering and drug delivery