One‐Step Generation of Core–Gap–Shell Microcapsules for Stimuli‐Responsive Biomolecular Sensing

Abstract

The versatile design of stimuli-responsive microparticles embedding valuable biomolecules has great potential in a variety of engineering fields, such as sensors, actuators, drug delivery, and catalysis. Here, results are reported on thermoresponsive core-gap-shell (TCGS) microcapsules made of poly(Nisopropylacrylamide) (PNIPAm), which encapsulate hydrophilic payloads in a simple and stable manner. These are realized by a one-step microfluidic approach using the phase separation of a supersaturated aqueous solution of NIPAm. Various designs of the microcapsules are achieved by individual control of the swelling or by incorporating pH-responsive comonomers of the inner core and outer shell. The gap, i.e., the space between the inner core and outer shell, can be loaded with cargo-like nanoparticles. The outer shell can serve as a stimuli-responsive gateway for the transport of smaller molecules from the external solution. It is shown that the TCGS microcapsules are suitable as temperature controllable glucose sensors and hold promise in the design of controllable enzymatic reactions. The proposed platform provides an avenue for developing a new-generation of microparticles for diverse and efficient engineering applications.

Fabrication of core–shell type poly(NIPAm)-encapsulated citral and its application on bamboo as an anti-molding coating

“…Moreover, due to the presence of a large number of active sites that can combine with other functional components, they are oen used as intelligent carriers for drug delivery systems. [32][33][34] Consequently, the use of PNIPAm as a carrier to encapsulate citral is expected to effectively eliminate its drawbacks and facilitate the control of the release of citral to ultimately improve its stability, utilisation efficiency, and antibacterial activity, which in turn is believed to achieve the durable anti-mold effect of bamboo. The most critical technology for achieving this goal is encapsulation.…”

From shaping to functionalization of micro-droplets and particles

“…5B ). 81 PDMS is by far the most widely used material for the microfluidic devices due to its advantages of transparency, flexibility, biocompatibility, and ease of mass-production. 82 In addition, lithography techniques (soft-lithography and photo-lithography) allow for the fabrication of highly complex flow channels with high resolution down to ∼1 μm, allowing multi-functions to be realized in the microdevice.…”

Multicompartmental Microcapsules for Enzymatic Cascade Reactions Prepared through Gas Shearing and Surface Gelation

“…Microfluidics offer higher control over the morphology and complexity of microcapsules. However, the use of surfactants and oils makes microfluidic methods less suitable for producing multicompartmental microcapsules for enzymatic cascade reactions. ,− Although some researchers prepared all-aqueous microcapsules by improving the traditional methods described above, only core–shell microparticles with the most simple architecture were developed. , Methods that enable the fabrication of all-aqueous multicompartmental microcapsules with a more complex structure remain an important objective.…”