(403f) Dynamic Encapsulation of Hydrophilic Nanomaterials in Hydrophobic Polymer-Based Particles by Simple Emulsion Technique

Various strategies of encapsulating hydrophilic materials, such as magnetite nanoparticles and drug molecules, have been developed and performed for applications in biological and medical fields. Polymer-based particles are attractive as carriers because of their high stability, process feasibility, and low cost. Even though emulsion polymerization or double emulsion has been reported for successful entrapment of hydrophilic nanomaterials within the hydrophobic polymer matrix, simple and efficient encapsulation is still being investigated. Here we introduce the novel dynamic encapsulation of hydrophilic magnetic nanoparticles or small drug molecules within hollow polylactic acid (PLA) particles by one-step oil in water (O/W) emulsion diffusion method. The formation of hollow polymer particles was based on the control of emulsification in the turbulent fluid flow and emulsification temperature. The fabricated PLA particles were found size and shape controllable by manipulating emulsification conditions. PLA-containing ethyl acetate solution was emulsified in the hydrophilic materials-containing aqueous medium and followed by the solidification of PLA particles in the diffusion step. The emulsion droplets dynamically formed multiple emulsion structure which entrapped hydrophilic materials within hydrophobic polymer matrix. Studies on optimizing the formulation, encapsulation efficiency, and emulsification process were performed. This method shows advantages of simple operation and easy control on fabricating the promising carrier of different hydrophilic materials for widespread use.