Theranostic Polyaniline-Integrated N-Acetyl-l-Cysteine Hydrogel for Synergistic Photothermal Antibacterial Therapy and Enhanced Cell Migration

Bacterial infections continue to pose a significant global health challenge, highlighting the urgent need for innovative therapeutic approaches that combine antibacterial efficacy with photothermal treatment modalities. In this study, we report a theranostic multifunctional hydrogel (APQ@NH), comprising Asiatic acid (AA)-doped polyaniline (PANi) loaded with quercetin (Q), and incorporated into an N-acetyl-l-cysteine (NAC)-based hydrogel matrix, for in vitro antibacterial and photothermal applications. The APQ@NH hydrogel exhibits excellent rheological stability and controlled, sustained drug release behavior, ensuring prolonged antibacterial activity. Upon near-infrared 808 nm laser irradiation, the APQ@NH hydrogel effectively generates localized hyperthermia, facilitating membrane disruption and enhancing the intracellular delivery of antibacterial agents. The photothermal conversion efficiency (PCE) of APQ@NH was calculated to be 21.7% under 808 nm laser irradiation, confirming its effective photothermal capability. This synergistic system exhibited potent antibacterial activity against both Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) , resulting in substantial bacterial eradication. Additionally, in vitro studies confirmed the hydrogel's ability to promote cell migration, further supporting its potential for wound healing applications.