biopolymer, lacked the electrical properties needed for cardiovascular engineering, with

the addition of PEDOT:PSS as conductive scaffolds to the CS/PVA, significant electrical

conductivity was achieved for heart tissue engineering.

Polydopamine (PDA) and PPy integrated polyacrylamide (PAM) (PDA−PPy−PAM)

hydrogel marked yet another high-performance soft electronic device. They exhibited

high intrinsic conductivity (12 S/m), high optical transparency (70% after 3 days), and

good UV-shielding performance and may prove beneficial for potential applications in

wound dressings, transparent electronic skins, and bioelectrodes.

A conducting hydrogel immobilized enzyme-based amperometric biosensor for glu­

cose determination onto a Pt electrode as a biotransducer was fabricated [5]. An enzyme-

loaded electroconductive polymeric hydrogel composite on Pt electrode was chemically

modified and functionalized with 3-aminopropyl-trimethoxysilane (APTMS), acryloyl

(polyethyleneglycol)-N-hydroxysuccinamide (AC-PEG-NHS), and polyHEMA cross-

linked hydrogel scaffold followed by electropolymerization of pyrrole in the presence of

glucose oxidase. The polymeric hydrogel composite–based bio-transducer rendered

higher catalytic bioactivity.

An injectable self-healing conductive hydrogel as a cell delivery vehicle for cardiac cell

therapy for the treatment of myocardial infarction was introduced [6]. CS grafted aniline

tetramer (CS-AT) and di-benzaldehyde terminated polyethylene glycol (PEG-DA)–based

conductive hydrogel was fabricated for cell treatment. Hydrogels exhibited conductivity

similar to that of the myocardium, suitable for cardiac repairing applications by reg­

ulating the electrical signals as well as showing self-healing, tissue adhesive, cell pro­

liferation, antibacterial activity, cell delivery ability in chosen H9c2 and C2C12 myoblasts

for cardiac repair.

Motivated by the challenges faced during the formation of elastic conducting polymer

hydrogel, Lu et al. developed conductive PPy hydrogels with extraordinary elasticity of

about 70% of compress strain [7] and this added several characteristics to the conducting

polymeric hydrogels such as shape memory, facile functionalization, fast removal of dyes

from wastewater, etc. They can also be conveniently transformed into pure organic,

electronically conductive, and elastic sponges by supercritical fluid drying technique with

magnificent stress-sensing performance. Such remarkable characteristics of PPy hydro­

gels render them an intelligent engineering material.

18.2.2 Conductive Hydrogels

Conductive hydrogel (CH) composites were popular, owing to their electronic func­

tionality and hydrophilic network. As the name implies, a conducting hydrogel is the

cross-linked hybrid network of hydrogels incorporated with conducting materials to

provide electrical conductivity. CHs have found potential applications in bioelectronics

such as implantable and electronic devices at cell/tissue interfaces. They are an ideal

candidate for implantable and ingestible devices, as cheap, elastic, and biocompatible,

biodegradable materials that are compliant with biological systems. Edible electronics are

another feather in the cap for physicians and researchers as a high-performing tool in

medical science. Edible devices are digestible within the body, suitable for treating the

gastrointestinal (GI) tract without any risk of retention. Various electronic devices based

on conducting hydrogels have been explored and employed successfully in biomedical

applications for targeted drug delivery, wound dressing, and disease monitoring due to

their good electronic properties and tunable mechanical flexibility.

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