Thread‐Like Radical‐Polymerization via Autonomously Propelled (TRAP) Bots

Abstract

Micromotor‐mediated synthesis of thread‐like hydrogel microstructures in an aqueous environment is presented. The study utilizes a catalytic micromotor assembly (owing to the presence of a Pt layer), with an on‐board chemical reservoir (i.e., polymerization mixture), toward thread‐like radical‐polymerization via autonomously propelled bots (i.e., TRAP bots). Synergistic coupling of catalytically active Pt layer, together with radical initiators (H2O2 and FeCl3 (III)), and PEGDA monomers preloaded into the TRAP bot, results in the polymerization of monomeric units into elongated thread‐like hydrogel polymers coupled with self‐propulsion. Interestingly, polymer generation via TRAP bots can also be triggered in the absence of hydrogen peroxide for cellular/biomedical application. The resulting polymeric hydrogel microstructures are able to entrap living cells (NIH 3T3 fibroblast cells), and are easily separable via a centrifugation or magnetic separation (owing to the presence of a Ni layer). The cellular biocompatibility of TRAP bots is established via a LIVE/DEAD assay and MTS cell proliferation assay (7 days observation). This is the first study demonstrating real‐time in situ hydrogel polymerization via an artificial microswimmer, capable of enmeshing biotic/abiotic microobjects in its reaction environment, and lays a strong foundation for advanced applications in cell/tissue engineering, drug delivery, and cleaner technologies.

Design of a self-unfolding delivery concept for oral administration of macromolecules

“…1B. An early 1 st generation design of the cavities for drug-and excipient loading in the PDMS foil was based on previously published cylindrical devices [20,21]. This 1 st generation foil designed with cylindrical cavities was used for initial in vitro assessment of the selfunfolding properties of the PDMS foil (Fig.…”

Development and characterization of a PDMS-based masking method for microfabricated Oral drug delivery devices

“…To further demonstrate the versatility and flexibility of the PDMS masking method, previously applied for selfpropelling micromotors (Srivastava et al 2019), we have explored microdevices designed and fabricated in various geometries, sizes, topologies and materials. It can be observed from the SEM images that the PDMS mask had fully embedded microdevices shaped as triangles and squares (Figure 5 (A1 -A2)).…”

“…As these devices become smaller and more complex, the methods for their handling and manipulation, e.g. drug loading (Fox et al 2015) or surface chemical modification (Srivastava et al 2019) need to be more precise and controllable. Alteration of surface properties, loading of drug compounds and general manipulation of microdevices can be achieved by masking techniques.…”

Recent progress on motion control of swimming micro/nanorobots

“…53 The chemical control methods also offered simple ways to excite behavior responded to chemical reactions without the need of external control systems. [54][55][56][57][58] The direction of the self-propelled were controlled by environmental gradient, external field, and confined space while the magnitude regulatory is achieve by adjusting chemical reaction rate. 59,60 One handy method for accelerating the chemical reaction is to increase the fuel concentration.…”