Interfacial assembly of dendritic microcapsules with host–guest chemistry

Abstract

The self-assembly of nanoscale materials to form hierarchically ordered structures promises new opportunities in drug delivery, as well as magnetic materials and devices. Herein, we report a simple means to promote the self-assembly of two polymers with functional groups at a water-chloroform interface using microfluidic technology. Two polymeric layers can be assembled and disassembled at the droplet interface using the efficiency of cucurbit[8]uril (CB[8]) host-guest supramolecular chemistry. The microcapsules produced are extremely monodisperse in size and can encapsulate target molecules in a robust, well-defined manner. In addition, we exploit a dendritic copolymer architecture to trap a small hydrophilic molecule in the microcapsule skin as cargo. This demonstrates not only the ability to encapsulate small molecules but also the ability to orthogonally store both hydrophilic and hydrophobic cargos within a single microcapsule. The interfacially assembled supramolecular microcapsules can benefit from the diversity of polymeric materials, allowing for fine control over the microcapsule properties.

One-Step Generation of Multifunctional Polyelectrolyte Microcapsules via Nanoscale Interfacial Complexation in Emulsion (NICE)

“…This method is distinctively different from polyelectrolyte coacervation at the interface of single oil-in-water emulsions, which leads to the formation of polyelectrolyte complex-covered oil droplets. [27][28][29][30][31][32][33][34] The NICE scheme, in contrast, would generate isolated water compartments in an aqueous environment. In addition to hydrophilic agents in the microcapsulate lumen, hydrophobic molecules or nanoparticles can be incorporated into the nanometric polyelectrolyte shell.…”

Microfluidic fabrication of hollow protein microcapsules for rate-controlled release

“…For encapsulation applications, microuidic platforms provide precise particle size control over a wide range, which is vital for ensuring product homogeneity. 8 Microuidic platforms have been reported for single-step processes for fabricating many sophisticated supramolecular microcapsules, for example, nonspherical particles, 11 porous microcapsules, 12 alginate microspheres, 13 dendritic microcapsules, 14 cross-linked protein capsules 15 and biological microgels. 16 Microuidic chips have also been deployed to trigger precisely controlled interfacial reactions for fabricating complex and multiple emulsions.…”

Host-Guest Chemistry in Layer-by-Layer Assemblies Containing Calix[n]arenes and Cucurbit[n]urils: A Review

“…A drawback of the LbL film-based microcapsules comes from the limited efficiency of encapsulation due to leakage of the cargo molecules during the film-coating process and dissolution of the template particles. In contrast, Abell and coworkers have developed a novel protocol for the preparation of polymer microcapsules capable of encapsulating sufficient amounts of cargo molecules [86][87][88][89][90][91]. The microcapsules are prepared using MV-modified Au nanoparticles and naphthalene polymers bridged by CB [8].…”

“…Interestingly, a protocol for the one-step preparation of polymer microcapsules has been developed using CB [8] in microfluidic devices [86][87][88][89][90][91]. Different techniques and materials can be used for the preparation of polymer microcapsules, such as polymersomes [92], self-assembled vesicles [93], and LbL films [94,95].…”