Self-healing hydrogels

Polymer chemistry

Tissue engineering

Ferrofluid

Quantum mechanics

Anisotropy

Composite material

Medicine

Magnetic field

Nanotechnology

Biomedical engineering

Materials science

Carbon nanotube

Physics

Electrical conductor

Biomaterial

Nano Letters

Anisotropic hydrogels with a hierarchical structure can mimic biological tissues, such as neurons or muscles that show directional functions, which are important factors for signal transduction and cell guidance. Here, we report a mussel-inspired approach to fabricate an anisotropic hydrogel based on a conductive ferrofluid. First, polydopamine (PDA) was used to mediate the formation of PDA-chelated carbon nanotube-Fe3O4 (PFeCNT) nanohybrids and also used as a dispersion medium to stabilize the nanohybrids to form a conductive ferrofluid. The ferrofluid can respond to an orientated magnetic field and be programed to form aligned structures, which were then frozen in a hydrogel network formed via in situ free-radical polymerization and gelation. The resulted hydrogel shows directional conductive and mechanical properties, mimicking an oriented biological tissue. Under external electrical stimulation, the orientated PFeCNT nanohybrids can be sensed by the myoblasts cultured on the hydrogel, resulting in the ori...

An Anisotropic Hydrogel Based on Mussel-Inspired Conductive Ferrofluid Composed of Electromagnetic Nanohybrids