Anisotropic Particles through Multilayer Assembly.

Abstract

The anisotropy in the shape of polymeric particles has been demonstrated to have many advantages over spherical particulates, including bio-mimetic behavior, shaped-directed flow, deformation, surface adhesion, targeting, motion, and permeability. The layer-by-layer assembly is uniquely suited for synthesizing anisotropic particles as this method allows for simple and versatile replication of diverse colloid geometries with precise control over their chemical and physical properties. This review highlights recent progress in anisotropic particles of micrometer and nanometer sizes produced by a templated multilayer assembly of synthetic and biological macromolecules. We overview synthetic approaches to produce capsules and hydrogels utilizing anisotropic templates such as biological, polymeric, bulk hydrogel, inorganic colloids, and MOF crystals as sacrificial templates. Structure-property relationships controlled by the anisotropy in particle shape and surface are discussed and compared with their spherical counterparts. We outline advances and challenges in controlling particle properties through varying shape anisotropy and surface asymmetry. We also discuss the perspective applications of anisotropic colloids in biomedicine, including programmed behavior in the blood and tissues as artificial cells, nano-motors/sensors, and intelligent drug carriers. This article is protected by copyright. All rights reserved.