Patterned Arrays of Supramolecular Microcapsules

Abstract

Micropatterning of hydrogel has brought innovative outcomes in fundamental and applied material sciences. Previous approaches have mainly been dedicated to fabricate arrays of bulk hydrogel beads, which have inherent challenges including loading ability, scalability, specificity, and versatility. Here, a methodology is presented to create hollow microcapsule arrays from sessile microdroplets. The difference in wettability between hydrophilic and hydrophobic surfaces enables self-partitioning of liquid into microdroplet arrays, serving as microreservoirs to load complementarily functionalized host-guest polymers, cucurbit[8]uril-threaded highly branched polyrotaxanes (HBP-CB[8]) and naphthyl-functionalized hydroxyethyl cellulose (HEC-Np). The interfacial dynamic complexation between positively charged HBP-CB[8] and HEC-Np occurs in the presence of negatively charged surfactants, resulting in con-densed supramolecular hydrogel skins. The hydrogel microcapsules are uniform in size and are developed to encapsulate target cargos in a robust and well-defined manner. Moreover, the microcapsule substrates are further used for surface enhanced Raman spectroscopy sensing upon loading of gold nanoparticles. This facile assembly of microcapsule arrays has potential applications in controlled cargo delivery, bio-sensing, high-throughput analysis, and sorting.

Spatially Controlled Supramolecular Polymerization of Peptide Nanotubes by Microfluidics

“…However, when an alkaline solution (NaOH 3.5 m m ) was injected in I T , a red‐shifted green fluorescent halo was observed in the droplet periphery (Figure E–H). The corresponding micrographs indicated a preferential adsorption of the supramolecular peptide nanotubes and microfibers at the perimeter of the water‐droplet interface (Figure G,H) in capsule‐like structures . Similar results were observed in fibrillation experiments using HEPES buffer (50 m m , pH 8) as to precisely control the pH increase (Supporting Information, Figure S5).…”

Dynamic Interfacial Adhesion through Cucurbit[n]uril Molecular Recognition

“…[13] In an effort to gain mesoscale CB [8]-mediated self-assembling,anew class of hydrophilic CB[n]-threaded highly branched polyrotaxanes (HBP-CB[n]) were synthesized through as emi-batch reversible addition-fragmentation chain-transfer polymerisation (RAFT). [23,24] Such HBP-CB[n]p olyrotaxanes are further exploited in this study as polymer adhesives,w hich are capable of dynamically bonding two soft materials through the interfacial CB[n]molecular recognition ( Figure 1). …”

Cucurbit[8]uril‐Based Polymers and Polymer Materials

“…We are not going to repeat the discussions here, but will give a brief update. In a recent work, a sessile microdroplet deposition method was used to prepare patterned arrays of supramolecular hydrogel microcapsules on a solid substrate via electrostatic interaction‐driven assembly . This methodology was based on the difference in wettability between the hydrophilic and hydrophobic patterned areas on a wettability‐tunable glass substrate, where self‐separated microdroplets were generated.…”