Microfluidic Engineering of Crater–Terrain Hydrogel Microparticles: Toward Novel Cell Carriers

Abstract

Fabrication and application of novel anisotropic microparticles are of wide interest. Herein, a new method for producing novel crater−terrain hydrogel microparticles is presented using a concept of droplet−aerosol impact and regional polymerization. The surface pattern of microparticles is similar to the widespread "crater" texture on the lunar surface and can be regulated by the impact morphology of aerosols on the droplet surface. Methodological applicability was demonstrated by producing ionic-cross-linked (alginate) and photo-cross-linked (poly-(ethylene glycol) diacrylate, PEGDA) microparticles. Additionally, the crater−terrain microparticles (CTMs) can induce nonspecific protein absorption on their surface to acquire cell affinity, and they were exploited as cell carriers to load living cells. Cells could adhere and proliferate, and a special cellular adhesion fingerprint was observed on the novel cell carrier. Therefore, the scalable manufacturing method and biological potential make the engineered microparticles promising to open a new avenue for exploring cell−biomaterial crosstalk.

Free‐Boundary Microfluidic Platform for Advanced Materials Manufacturing and Applications

“…In this section, we focus on four types of FBMM, including hydrodynamics-based, interfacial tension-based, acoustics-based, and electrodynamics-based (Figure 2). The hydrodynamics-based FBMM includes the flow focusing, [50,58,60,[81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97] co-flow, [62,63, cross-flow, [61,[129][130][131][132][133][134][135][136][137][138][139] and free jet channel geometries. [56,[140][141][142][143][144][145][146] The interfacial tension-based FBMM includes single-axial, oblique, and spinning.…”

“…[60] Airdriven co-flow allows further surface treatment of droplets after their generation by using droplet-aerosol impact and regional polymerization to obtain a richer surface microstructure. [63] Rotational cross-flow enables uniform, high-volume preparation of high-density, high-surface-tension droplets in a stationary continuous phase. [139] Air-driven cross-flow can impart more surface morphology and microstructure to the particles, such as multifunctional helical microstructures.…”

“…Gas-Driven Co-Flow: In addition to flow-focusing configuration, co-flow can also be used for the manufacturing of materials. [62,63,98,[100][101][102][103][104][105][106][107][108][109][110][111][112][113][114][115][116][117][118]128] Using external air flow to drive internal phase liquid flow, high-definition single-cell printing can be realized (Figure 4A). The speed, accuracy, and flexibility of the approach were studied.…”

“…FBMM can impart richer structures to materials, such as helical structures and crater-terrain structures, which can be used for heterogeneous organoid and cell culture research. [63,132] FBMM can handle high surface tension and high-density fluids and give them anisotropic structures, which have great application prospects in the field of flexible electronics. [60,139] FBMM can be used in the fabrication of ultra-fine fibers and endow them with superb functions and properties for high-performance artificial muscles and high-precision sensing.…”

“…B) Air-driven co-flow based on aerosol impact and regional polymerization for crater-terrain hydrogel microparticles production. Reproduced with permission [63]. Copyright 2020, American Chemical Society.…”