Physicochemical dual cross-linked multifunctional conductive organohydrogel sensors for fireworks burn wound healing and intelligent real-time monitoring

This study is led by Chuang Du (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China), Weiwei Liu (Stomatological Hospital, Jilin University, Changchun 130021, China) and Lei Wang (Key Laboratory of Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun 130023, China).

The rapid advancement of flexible electronics technology has opened up promising applications in various fields such as wearable devices, soft robots, human-computer interaction, electronic skin, and flexible energy storage devices. In particular, hydrogel has garnered significant attention in the wearable technology sector due to its ability to conform closely to the skin. Flexible hydrogel wearable sensors play a crucial role in converting stimulus signals into easily observable electrical signals, making them popular in areas like motion sensing and biomedical monitoring. By combining the flexibility of hydrogels with the structural and electrochemical properties of conductive materials, conductive hydrogels offer a promising alternative to traditional rigid electronic devices. These conductive hydrogels, categorized into electronic and ionic types, typically incorporate materials such as graphene, Mxene, carbon nanotubes, ionic liquids, and liquid metals to enhance conductivity while maintaining flexibility through the formation of a continuous conductive channel within the network.

While many studies have focused on the fundamental properties of flexible sensors, such as flexibility, electrical conductivity, and sensing sensitivity, the application of these sensors in medical monitoring is still in monitoring motion signals. Burns are a common type of tissue damage caused by factors such as flames, high temperatures, and intense radiant

heat. Festivals and celebrations involving fireworks can bring joy, but mishandling of fireworks can lead to dangerous situations. Every year, hospital emergency departments

globally see cases of burns caused by fireworks, with a significant number affecting the skin on the hands and face. While some of these burns may be minor, delays in treatment can hinder the healing process and lead to scarring. Prompt emergency treatment for burns is crucial to minimize scarring and reduce the risk of infection. Emergency cooling immediately after a burn can effectively slow down skin damage, alleviate pain, and help prevent wound progression. Therefore, the development of conductive hydrogel-based sensors is urgently needed for emergency treatment and real-time smart monitoring following burns.

Eggshell membrane (ESM) is a valuable resource with high potential for utilization. It is rich in collagen, chondroitin sulfate, hyaluronic acid, glycoproteins, and other bioactive compounds that promote cell growth and improve joint health. These properties make ESM widely used in biomedical materials. For instance, Zhang et al. enhanced the performance of oxidized eggshell membrane through oxidative modification of ESM, creating a self-healing, mechanically strong, adhesive, and biocompatible hydrogel dressing that effectively promotes wound healing. Moreover, catechol-coupled chitosan (CS−GA), produced by reacting gallic acid with chitosan, addresses the solubility issue of chitosan in neutral systems and serves as an antimicrobial agent in biomedical applications. Additionally, tannic acid (TA), a natural polyphenolic compound known for its antimicrobial and antioxidant properties, is commonly used in hydrogel preparation. To cater to burn aftercare needs, a multifunctional conductive hydrogel sensor has been developed, combining cooling, antimicrobial, pro-healing, and real-time monitoring capabilities while maintaining essential flexibility as a sensor.

In this work, a multifunctional conductive hydrogel (P-EPL/CT) was developed using a physical-chemical dual cross-linking approach involving poly(vinyl alcohol) (PVA), CS−GA, TA, ESM, lysozyme, and 4am-PEG-MAL. The hydrogel network system was enhanced through the formation of numerous noncovalent hydrogen bonds during the freezing-thawing process of PVA, CS−GA, and TA, resulting in the creation of a rigid network structure. Furthermore, a soft network was established through the self-assembly of ESM, lysozyme, and 4am-PEG-MAL via chemical cross-linking. The use of ionic liquids/ethylene glycol/water (ILs/EG/H₂O) ternary solvents instead of a single solvent provides freeze resistance and electrical conductivity. The incorporation of polyphenol compounds and lysozyme not only enhanced the mechanical properties of the hydrogel but also endowed it with remarkable antimicrobial capabilities, thereby reducing the risk of wound infections. The hydrogel’s cooling performance and wound healing promotion were evaluated using a mouse model of fireworks burns, and its potential application as a flexible strain sensor for monitoring various body joints was explored, with promising implications for wound healing monitoring. Overall, this study successfully developed a hydrogel flexible sensor with diverse functionalities to tackle the challenges associated with post-treatment of fireworks burns and wound healing promotion.

See the article:

Physicochemical Dual Cross-Linked Multifunctional Conductive Organohydrogel Sensors for Fireworks Burn Wound Healing and Intelligent Real-Time Monitoring

https://doi.org/10.1021/polymscitech.4c00018