Multifunctional antifreeze gelatin-based ionic conductive organohydrogel coupled with electrical stimulation for monitoring and accelerated wound healing

Introduction

Traditional hydrogels with poor mechanical properties and lack of biological activities severely limit their application in wound therapy. Designing multifunctional hydrogels for monitoring and accelerating wound healing remains imperative.

Objectives

The aim of this study is to develop a multifunctional antifreeze ionic conductive Gel-TBA@organohydrogel with antibacterial, anti-inflammatory and antioxidant properties for monitoring and wound treatment.

Methods

The Gel-TBA@organohydrogel were developed through simply adding 2,3,4-trihydroxybenzaldehyde (TBA) into the gelatin (Gel) solution, and further immersed in water/glycerol binary solvent containing ZnSO₄ for solvent replacement and salting out. Meanwhile, the antifreeze, antibacterial, anti-inflammatory, antioxidant, conductive and biocompatible properties of the organohydrogels were systematically evaluated. Also, the sensing measurements of the Gel-TBA@organohydrogel were carried out to monitor human behaviors, wound exudates and humidity. Furthermore, the wound healing ability of the organohydrogels in combination with electrical stimulation (ES) was investigated by in vivo and ex vivo experiments.

Results

Assisted by TBA addition and binary solvent immersion, Gel-TBA@organohydrogel not only exhibits significant antibacterial and ROS scavenging capabilities, but also has commendable mechanical properties (tensile strain: 346 %, toughness: 1.54 MJ/m³) due to the Schiff base reaction, hydrogen bonding and coordination interaction. In addition, it shows significant conductive sensitivity in the strain range of 60 % to 150 % (GF = 1.54). Interestingly, the organohydrogels exhibit excellent anti-freezing capacity that maintains mechanical strength and electrical properties at −18 °C. Furthermore, Gel-TBA@organohydrogel has good sensing capabilities, responding to wound exudates, humidity and body movement. In vivo experiments showed that the wound healing rate of Gel-TBA@organohydrogel co-treated with ES reached 98.59 % on day 14, with high expression of collagen deposition (90.10 ± 2.35 %), which promoted wound healing and new tissue regeneration.

Conclusion

The Gel-TBA@organohydrogel holds promise for applications in sensing and wound healing, wherein it shows multifunctional abilities and can detect wound exudates and motion behavior, thereby enabling the effective wound care management.