Design And Biological Application Of Conductive Hydrogels

In the past 20 years,the field of tissue engineering has developed rapidly,and which primary goal is to develop functional biological substitutes to regenerate or replace damaged tissues and organs,to further restore,maintain and improve tissue function.Conductive hydrogels not only have the structure and properties of extracellular matrix-like materials,but also can enhance intercellular communication,promote tissue regeneration,and have become the most potential bioactive materials in tissue engineering.Based on the key clinical problems,how to give the conductive hydrogel multiple functions in a targeted way while making it have both biomedical functions and realize the parallelization of physiological response and external stimulus response is the critical problem to be solved in the practical application of hydrogel.Therefore,this paper focuses on preparing conductive hydrogels and aims to solve practical problems in biomedicine.It is committed to developing conductive hydrogel materials with biological activity and has carried out the following work.First,a multifunctional conductive hydrogel was constructed by supramolecular self-assembly to accelerate the repair of diabetes wounds.Attributed to its good electrical activity and antibacterial properties,the conductive hydrogel can accelerate the healing of diabetes wounds by promoting intercellular signal transduction and preventing wound infection.In addition,inspired by the endogenous electric field,we further combined electrical stimulation with conductive hydrogel and found that this combined treatment strategy can comprehensively improve the wound healing of diabetes through local immune regulation,promoting collagen deposition,and promoting nerve and angiogenesis.This synergistic strategy of multifunctional hydrogel combined with electrical stimulation is of great significance for the clinical treatment of chronic diabetes wounds.Secondly,in order to solve the "black box" problem of wound monitoring caused by the opacity of most conventional conductive hydrogel dressings,a conductive hydrogel dressing with high transparency,strong adhesion and high mechanical properties was constructed.The natural plant glycyrrhizic acid and amphoteric polyelectrolyte as raw materials and combining into the hydrogel system.Benefiting from the inherent reducibility of glycyrrhizic acid,a concentration gradient Ag NPs layer was in-situ prepared on the surface of the hydrogel using the green preparation technology,and the hydrogel was endowed with broad-spectrum and lasting antibacterial activity by blocking the invasion of exogenous bacteria.The conductive hydrogel dressing can accelerate the healing of diabetes wounds by preventing wound infection,local immune regulation,improving the inflammatory microenvironment and promoting the generation of blood vessels and nerves.In addition,the therapeutic effect of diabetes wounds has been further improved combined with the treatment of electrical stimulation.The multifunctional conductive hydrogel combined with electrical stimulation provides a new direction for related clinical practice.Afterwards,in order to repair chronic diabetes wounds with irregular shapes and uneven depths,an injectable conductive hydrogel dressing was designed.The hydrogel showed many favorable properties such as self-healing,tissue adhesion,antioxidant,and antibacterial activity.And further combined with electrical stimulation technology to repair deep wounds of diabetes.The results of animal experiments showed that electrical stimulation combined with injectable conductive hydrogel could promote wound healing in diabetes by preventing wound infection,reducing oxidative stress,accelerating collagen deposition,and promoting angiogenesis and neurogenesis.This combined treatment strategy has significantly improved the therapeutic effect of diabetes deep wound repair,showing great application potential.Finally,the conducive material was introduced into the hydrophobic association hydrogel system,and a conductive hydrogel with good tensile and self-healing properties was developed,which could be used as an intelligent sensor to monitor various movements and physiological signals of the human body.The hydrogel smart sensor showed a wide strain window,fast response speed and excellent strain sensitivity.In addition,a balloon-shaped hydrogel sensor was prepared using this material,which was used to isolate tumors and peritumoral organs in brachytherapy,significantly reducing radiation damage to peritumoral organs during radiotherapy.The radiation attenuation process was simulated by the size change of the expansion of the hydrogel balloon,and an APP was used to monitor the safety distance and range provided by the hydrogel balloon under different radiation risks.The conductive hydrogel sensor opens a new way for exploring multi-functional applications in human-computer interaction,biomedical engineering and bionics.