Intrinsic Antibacterial and Conductive Hydrogels Based on the Distinct Bactericidal Effect of Polyaniline for Infected Chronic Wound Healing

Abstract

Most chronic wounds suffer from infections, and their treatment is challenging. The usage of antibiotics may lead to bacterial resistance and adverse side effects. Positively charged substances have shown promise, but their applications are usually limited by certain cytotoxicity or complex synthesis. Doped polyaniline that carries a high density of positive charges would be a promising candidate due to its good biocompatibility and easy availability, but its interaction with bacteria has not been elucidated. Herein, the distinct bactericidal effect of polyaniline against Gram-positive bacteria has been verified. The antibacterial activity may result from the specific interaction with lipoteichoic acid to destroy the Gram-positive bacterial cell wall. Polyaniline and a macromolecular dopant (sulfonated hyaluronic acid) are used to construct a flexible hydrogel with skin-mimic electrical conductivity. The in vivo results demonstrate that electrical stimulation (ES) through this hydrogel is superior to ES via separated electrodes (the ES strategy used clinically) for promoting infected chronic wound healing.

Advances in Hyaluronic Acid for Biomedical Applications

“…application in vascular tissue engineering (Yu et al, 2020). Wu et al (2021) used polyaniline and sulfonated hyaluronic acid to construct flexible hydrogels with simulated skin conductivity. In vivo results showed that the electrical stimulation method by this hydrogel was superior to the present clinical electrical stimulation strategy to promote the healing of infected chronic wounds.…”

“…Data showed that HA with a higher sulfonation degree had stronger functions of inhibiting inflammatory macrophages, promoting the adhesion, proliferation, and migration of EC and regulating and maintaining the contractile phenotype of SMCs ( Yu et al, 2020 ), which is a promising potential application in vascular tissue engineering ( Yu et al, 2020 ). Wu et al (2021) used polyaniline and sulfonated hyaluronic acid to construct flexible hydrogels with simulated skin conductivity. In vivo results showed that the electrical stimulation method by this hydrogel was superior to the present clinical electrical stimulation strategy to promote the healing of infected chronic wounds.…”

Construction of multifunctional wound dressings with their application in chronic wound treatment

“…23 Professor Wang's group developed a series of conductive hydrogels for chronic wound treatment. [96][97][98][99] For example, they initiated the polymerization of aniline monomers in situ in polyacrylamide hydrogels to construct a novel conductive hydrogel dressing. 96 They found that sulfonated HA-doped polyaniline with a high density of positive charges could specifically interact with lipoteichoic acid to disrupt Gram-positive bacterial cell walls.…”

Smart Antifreeze Hydrogels with Abundant Hydrogen Bonding for Conductive Flexible Sensors

“…However, most hydrogels lack conductivity due to the insulating properties of conventional polymer networks. Commonly used methods to enhance the conductivity of hydrogel include filling conductive fillers (graphene [ 17 , 18 ], carbon nanotubes [ 19 , 20 ], polypyrrole [ 21 , 22 ] and polyaniline [ 23 ], etc.) or adding soluble electrolytes (e.g., LiCl, NaCl, and (NH 4 ) 2 SO 4 ) [ 24 , 25 , 26 , 27 , 28 ].…”