Histidine-Triggered GO Hybrid Hydrogels for Microfluidic 3D Printing

Abstract

Graphene oxide (GO) hydrogels have provided tremendous opportunities in designing and fabricating complex constructs for diverse applications, while their 3D printing without photocuring is still a challenging task due to their low viscosity, uncontrollable gelation, and low interfacial tension. Here, we report a histidine-assisted printing strategy to prepare GO hybrid hydrogels through the microfluidic 3D printing technique. We found that the GO additive could significantly hamper the Knoevenagel condensation (KC) reaction between benzaldehyde and cyanoacetate group-functionalized polymers to form a hydrogel, while these GO mixed solutions were rapidly solidified into a hydrogel when histidine was added. This fascinating phenomenon enabled us to prepare low-viscosity GO mixed polymer solutions as printable inks and generate hydrogel microfibers in histidine solutions. The hydrogel fibers could support cell survival and be further constructed into complex 3D structures through microfluidic 3D printing techniques. Moreover, due to the addition of GO, the microfibers exhibited excellent electrical conductivity and could sense the motion changes and convert these stimuli as electrical resistance signals. This strategy adds an option for the design and application of 3D printable aqueous GO inks in many fields.

In situ crystal engineering on 3D-printed woodpile scaffolds: a monolith catalyst with highly accessible active sites for enhanced catalytic cracking

“…[16][17][18][19][20] 3D printing, also known as additive manufacturing, is a layer-by-layer solidication process that provides benets such as high precision, material versatility, and digital/exible design. [21][22][23][24][25][26][27] As reported by Stuecker and coworkers, 3D-printed porous monoliths create no line-of-sight pathways and generate highly turbulent ows in the catalytic reaction, promoting enhanced mass transfer without sacricing much pressure drop when compared to traditional extruded-honeycomb monoliths. 28 To date, various 3D-printed monolithic catalysts using zeolites as the major active component have been fabricated, showing promising applications in catalytic cracking, ethylene oxidation, xylene isomerization, and a-pinene isomerization reactions.…”

Applications of Graphene in Five Senses, Nervous System, and Artificial Muscles

“…Third, smart textiles may combine the transduction and therapy in one system for personalized healthcare. − The 3D printing may reduce the manufacturing cost of hydrogel based wearable sensors. , …”

“…344−346 The 3D printing may reduce the manufacturing cost of hydrogel based wearable sensors. 347,348 The emerging trends of smart homes can be connected by the Internet of Things. 349−351 Indeed, wireless communications allow the transmission of sensing data in portable devices.…”

Designing self-healing hydrogels for biomedical applications

“…Besides, the generated CQC double bond could respond to multiple stimuli such as pH, 82 temperature, 83 and other small molecules. 84,85 Based on these properties, hydrogels prepared from the dynamic CQC double bonds displayed excellent self-healing, injectable, and thermoplastic properties. In recent studies, the KC reaction has been proven to produce various biomedical dynamic hydrogels.…”