Self‐Folded Hydrogel Tubes for Implantable Muscular Tissue Scaffolds

Abstract

Programming materials with tunable physical and chemical interactions among its components pave the way of generating 3D functional active microsystems with various potential applications in tissue engineering, drug delivery, and soft robotics. Here, the development of a recapitulated fascicle-like implantable muscle construct by programmed self-folding of poly(ethylene glycol) diacrylate hydrogels is reported. The system comprises two stacked layers, each with differential swelling degrees, stiffnesses, and thicknesses in 2D, which folds into a 3D tube together. Inside the tubes, muscle cell adhesion and their spatial alignment are controlled. Both skeletal and cardiac muscle cells also exhibit high viability, and cardiac myocytes preserve their contractile function over the course of 7 d. Integration of biological cells with smart, shape-changing materials could give rise to the development of new cellular constructs for hierarchical tissue assembly, drug testing platforms, and biohybrid actuators that can perform sophisticated tasks.

Shapeable Material Technologies for 3D Self‐Assembly of Mesoscale Electronics

“…In contrast, to the gradient crosslinking approach, the multilayer heterogeneous structures (Figure c) containing swelling and reinforcing layers can be prepared with a great deal of control using mass fabrication techniques . Application of stimuli responsive hydrogel materials, such as thermally and pH sensitive films, reinforced with rigid nonswelling polymeric layers allows for a reversible self‐assembly of the structure upon temperature or pH change that then triggers the swelling or de‐swelling of the polymers . Patterned hydrophobic reinforcing layers, can be introduced below, inside, or on top of the hydrogel layer, resulting in nontrivial transformations (Figures and d) of the geometry during the swelling/shrinking process after being released from the substrate .…”

Biodegradable Untethered Magnetic Hydrogel Milli‐Grippers

“…Also, compared to the fabrication strategy of bilayer-based soft grippers and self-folded actuators, which have a soft and stiff layer with heterogeneous swelling degrees to fold into 3D shape, our method avoids further alignment processes of secondary materials. [50,51] From the materials point-of-view, compared to the previously presented actuators, including polyurethane-based elastomeric films embedded with SPION chains, [37] our hydrogel milli-gripper is composed of fully biodegradable material, which addresses one of the main challenges of small-scale untethered magnetic robots toward the pursuit of clinical relevance. www.afm-journal.de www.advancedsciencenews.com…”

Shape Morphable Hydrogel/Elastomer Bilayer for Implanted Retinal Electronics

“…Torsion, bending, and buckling can be generated by the residual stress and eventually lead to the shape transformation from a two-dimensional (2D) to a three-dimensional (3D) structure [4,5]. Hybrid bilayers have various applications including cell encapsulation [6][7][8], drug delivery [9], micro robots [10], actuators [11][12][13], and flexible electronics [14][15][16][17][18].…”

“…Metallic bilayer actuators [19,20] have a long history in sensing, but exhibit small shape changes and usually are responsive only to temperature change. In contrast, hydrogels can respond to various stimuli, including temperature, pH, light, chemicals, and electrical field [21] and have a larger extent of shape change [8]. When hydrogel is constrained by the passive layer with a different swelling property, the swell or de-swell of the hydrogel can induce internal residual stress and result in shape transformation.…”