Preparation of micro-/nano-nonspherical polymer particles

Precisely shaped polymer particles are widely used for various applications, especially in the design of new carriers for drug delivery, micro-or nano-nonspherical polymer particles exhibit more obvious advantages to their corresponding spherical particles, such as in the drug release, in vivo transportation, circulation, targeting ability, the swallow speed by the cells, and the adhesion behavior on vascular wall. If we can prepare the nonspherical particles with specific shape for the drug carriers, it will greatly enhance in vivo therapy efficiency. But in the particle research field, until now, spherical system research is in the dominate position, so it' s necessary to summarize the preparation methods of the micro-or nano-nonspherical polymer particles. In this review, 14 preparation methods ( microfluidics, stretching of spherical particles, porous silica, template and particles self-assembly, particle replication in nonwetting templates, reactive ion etching, electrospray, ion beam irradiation, controlled phase separation in seeded polymerization, miniemulsion polymerization, local surface modification at the Interface, amphiphilic macromolecule self-assembly, oil-in-water emulsion solvent evaporation technique, Y-shape surfactant) as well as their advantages and disadvantages of micro-or nano-nonspherical polymer particles are introduced in detail. These methods could be joined up to prepare more complex shapes.