Direct and controllable preparation of uniform PLGA particles with various shapes and surface morphologies

Abstract

Abstract Biodegradable polymeric particles have been widely used in the biomedical fields such as drug carriers, tissue engineering, and medical imaging. It has been recognized that the physical properties of particles, such as size and shape, have a profound influence on their functions. However, it is not easy to prepare non-spherical particles by the conventional emulsion-based method because the minimization of interfacial energy leads to the spontaneous formation of spherical emulsions and it is difficult to control the uniformity and size. In order to solve this problem, we developed a direct method to fabricate non-spherical polylactic-co-glycolic acid (PLGA) particles with uniform size. This method employed a common agent, phosphate buffer saline (PBS), as the deformation initiator and combined the premix membrane emulsification technique with the solvent evaporation method to prepare uniform non-spherical particles of various shapes with aspect ratios from 2 to 40 and various sizes ranging from 800 nm to 60 μm (long axis). We found that the external driving force of stirring and the interfacial tension of the droplet dictated by the constitution of PBS and polyvinyl alcohol (PVA) have synergistic effects on the deformation. Through confocal laser microscopy (CLSM), the deforming process was observed visually in the solvent and gel state during the solidification. Moreover, octreotide acetate as a model peptide was successfully encapsulated into the non-spherical particles. The results indicated that the deformation process did not influence the encapsulation efficiency and bioactivity of the peptide, proving the feasibility of using non-spherical particles as potential drug delivery systems.