|Title||Hierarchical patterning via dynamic sacrificial printing of stimuli-responsive hydrogels.|
|Publication Type||Journal Article|
|Year of Publication||2020|
|Authors||Wen, H, Li, J, Payne, GF, Feng, Q, Liang, M, Chen, J, Dong, H, Cao, X|
|Date Published||2020 Mar 10|
Inspired by stimuli-tailored dynamic processes that spatiotemporally create structure and function diversity in biology, a new hierarchical patterning strategy is proposed to induce the emergence of complex multidimensional structures via dynamic sacrificial printing of stimuli-responsive hydrogels. Using thermally-responsive gelatin (Gel) and pH-responsive chitosan (Chit) as proof-of-concept materials, we demonstrate that the initially printed sacrificial material (Gel/Chit-H+ hydrogel with a single gelatin network) can be converted dynamically into non-sacrificial material (Gel/Chit-H+-Citr hydrogel with gelatin and electrostatic citrate-chitosan dual-network) under the cues of stimuli (citrate ion). Complex hierarchical structures and functions can be created by controlling either the printing patterns of citrate ink or diffusion time of citrate ion into the Gel/Chit-H+ hydrogel. Specifically, mechanically-anisotropic hydrogel film and cell patterning can be achieved via 2D patterning, complex external and internal 3D structures can be fabricated in stimuli-responsive hydrogel and other hydrogel that is not stimuli-responsive under experimental conditions (also owing to erasable properties of Gel/Chit-H+-Citr hydrogel) via 3D patterning, interconnected or segregated fluidic network can be constructed from the same initial 3D grid structure via 4D patterning. Our method is very simple, safe and generally reagentless, and the products/structures are often erasable, compatible and digestible, which enables advanced fabrication technologies (e.g., additive manufacturing) to be applied to a sustainable materials platform.