An antimicrobial and adhesive conductive chitosan quaternary ammonium salt hydrogel dressing for combined electrical stimulation and photothermal treatment to promote wound healing.

The aim of this study is to investigate the effect of the adhesive, conductive hydrogel on wound healing when used as a therapeutic dressing. Herein, a dressing of PVA/QCS/TP@Fe (PQTF) was designed and prepared integrating polyvinyl alcohol (PVA), chitosan quaternary ammonium salt (QCS), tea polyphenol (TP), and ferric ions (Fe) by a simple one-pot and freeze-thaw method. In view of the comprehensive properties of PQTF hydrogel, including adhesion, electrical conductivity, and swelling performance, PQTF was selected for subsequent in vitro and in vivo healing promotion studies. PQTF had good adhesion and conductive ability, which was suitable for human motion monitoring and wound treatment. Notably, the PQTF showed and controllable human safety temperature thresholds (~44.8 °C) under near-infrared light (NIR). Meanwhile, PQTF achieved nearly 100 % antibacterial activity against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas putida (P. putida), methicillin-resistant Staphylococcus aureus (MRSA). In addition, the PQTF hydrogel dressing was demonstrated to achieve 99.59 ± 4.11 % would healing rate in a mouse trauma model under the dual stimulation of NIR (808 nm) and electricity (1.5 V direct current). The versatile PQTF hydrogel is a promising dressing for enhancing wound closure integrating with electrical stimulation (ES) and photothermal therapy.