Preparation And Properties Of Artificial Muscles Based On Electric Field Sensitive Hydrogels

In our daily life,the use of electricity brought us convenience in all aspects.However,with the frequent use of electricity,various safety accidents have followed.Electric injury(EI)accounts for a large proportion of these safety accidents.Electric burns can cause tissue damage and necrosis,especially progressive necrosis of muscle tissue.Muscular tissue is the largest body tissue and it can provide power to the body.Since muscle tissue plays an important role in the body,and electrical burns often cause damage to the muscle tissue,Therefore,regenerating and repairing the missing muscle tissue of an electric burn patient becomes an important issue in the field of medical rehabilitation.Currently,the method of treatment of muscle tissue damage mostly by allogeneic or autologous skeletal muscle tissue.However,the number of autologous tissue transplant donors is limited,and allograft transplantation is prone to long-term immunological rejection.Clinically,artificial synthetic materials such as polypropylene are also used as a support material for repairing muscle damage.However,these artificial synthetic materials have poor effects of inducing tissue regeneration and can cause series of adhesion reactions.Electric field-sensitive hydrogels can be deformed by electric field stimulation to achieve the conversion of electrical energy and mechanical energy.Compared to other rigid materials,electrosensitive gels have broad application prospects in micro-mechanics,actuators,and artificial muscle tissue.Aiming at clinical problems of patients with muscle damage,this research plans to develop a kind of electric field sensitive hydrogel material artificial muscle.The material has the advantages of rapid reaction under electric field,bending motion,sufficient mechanical properties and good biocompatibility,not only provides mechanical support for injured muscle tissue,it also provides scaffolding for cell transplantation and growth factor delivery.This topic firstly combines chitosan with carboxymethyl chitosan,adding a certain concentration of polyvinyl alcohol,cross-linking with a certain concentration of cross-linking agent,and preparing an electric field-sensitive hydrogel material through repeated freezing and thawing.After orthogonal experiment and single factor test,the optimal preparation process was simultaneously screened out under the two properties of electric field sensitivity and mechanical properties.The SEM and FIRT proved that the gel material was tightly bound and the cross-linking reaction between chitosan and glutaraldehyde occurred.The porosity of the material was 97.67%.The mechanical properties test shows that the gel material has good mechanical properties and elongation at break,which meets the mechanical requirements of natural muscles.The electric field sensitive behavior test results of the gel material show that the gel material has a good electric field response behavior.The in vitro degradation experiment showed that the degradation rate was 2%,the degradation was very slow,and the overall structure was stable.During the degradation process,the mechanical properties and electric field sensitivity of the gel material did not change significantly,and the properties were stable.n vivo degradation experiments showed that the gel material was implanted subcutaneously in rabbits.No obvious lump,inflammation,and other significant tissue immune response and dissociation were observed at the site of implantation.One month after implantation,rabbits were harvested and tested for loss of solution.The rate was only 0.27%,and the degradation was slow.H&E staining of tissue sections showed that the tissue cells in the site of the implanted material grew well.Blood compatibility experiments showed that the hemolysis rate of the gel material was less than 5%;the platelet adhesion rate was much lower than 40%;and it had good anticoagulant properties.The material has good blood compatibility;the cell experiment results show that the gel material has no cytotoxicity to mouse L-929 cells and human skeletal myoblasts(HSK).The study shows that the electric field sensitive hydrogel material prepared in this project has good electric field sensitivity,can be sensitively driven under the electric field and has good mechanical properties and biological properties.It is expected to be used in muscle damage caused by electrical burns and to repair the patient’s movement.