Multifunctional Stimuli-Responsive Hydrogels with Self-Healing, High Conductivity, and Rapid Recovery through Host–Guest Interactions

Abstract

Self-healing hydrogels with multifunctionality as a type of fascinating material show potential application in various fields, such as biomedicine, tissue engineering, and wearable electronic devices. However, to combine the properties of autonomous self-healing property, high conductivity, excellent mechanical properties, and stimuli-responsive properties for hydrogel is still a great challenge. Herein, we present self-healing conductive hydrogels based on β-cyclodextrin (β-CD), Nisopropylacrylamide (NIPAM), multiwalled carbon nanotubes (CNT) and nanostructured polypyrrole (PPY). Among them, β-CD served as the host molecule, and NIPAM served as the guest molecule, CNT as the physical cross-linker and conducting substrate, and PPY as the highly conductive component, respectively. The obtained hydrogels exhibit high conductivity, selfhealing property, flexible and elastic mechanical property and rapid stimuli-responsive property both to temperature and nearinfrared (NIR)-light together. The excellent characteristics of the hydrogels are further illustrated by pressure-dependent sensors, large-scale human motion monitoring sensors and self-healable electronic circuit. Cytotoxicity test indicated that they are nontoxic to L929 fibroblast cells and C2C12 myoblast cells. Taken together, these multifunctional hydrogels are excellent candidates for stimuli responsive electrical devices, artificial organs, and so on.

Adhesive Hemostatic Conducting Injectable Composite Hydrogels with Sustained Drug Release and Photothermal Antibacterial Activity to Promote Full‐Thickness Skin Regeneration During Wound Healing

“…Characterizations : The FT‐IR, nuclear magnetic resonance ( 1 H NMR), UV–vis spectroscopy, SEM, and rheological measurements were used to confirm the physical and chemical characterizations of HA‐DA, rGO@PDA, or HA‐DA/rGO hydrogels. The specific details of thermal stability, conductivity test, swelling, and degradation test are available in the Materials and methods section of Supporting Information.…”

Cytocompatible, Injectable, and Electroconductive Soft Adhesives with Hybrid Covalent/Noncovalent Dynamic Network

“…[1][2][3] The incorporation of electroconductive elements to hydrogels is an attractive design approach that combines the viscoelastic and mechanical properties of hydrogels with the conductivity of organic electronics. [11][12][13][14] However, the state-of-the-art technology suffers from particular properties of conductive polymers, such as high hydrophobicity and insolubility, resulting in low adherence to wet substrates and poor penetration into living tissues. [8][9][10] Conductive polymers, such as polypyrrole (PPy), polyaniline (PAni), and poly (3,4-ethylenedioxythiophene) (PEDOT), have been used in the synthesis of electroconductive hydrogels due to their high conductivity and ease of processing.…”

“…[18][19][20] To incorporate new functions to a conductive polymer for biomedical utilities, there are several limits of "add-on" approach because it does not alter the intrinsic properties of the electroconductive hydrogel network. [12] While the materials have shown high cytocompatibility for 2D cell culture, the covalent crosslinking reaction does not permit cell encapsulation in 3D hydrogel and completely impair the network dynamics mediated only by host-guest interaction. An attractive avenue is to develop self-assembled physical electroconductive hydrogels.…”

Poly(vinyl alcohol)–Carbon Nanodots Fluorescent Hydrogel with Superior Mechanical Properties and Sensitive to Detection of Iron(III) Ions

“…When the large strain returned to small strain, G ′ and G″ were adjusted again. The network was rebuilt when subjected to small strain, and the network was destroyed when experiencing large strains . This was the reason why hydrogel could produce self‐healing.…”