Mussel-inspired Electroactive And Anti-oxidative Scaffolds For Enhancing Skin Wound Healing

The scaffold is a good wound repair material,and its porous structure can facilitate the growth of cells and the formation of extracellular matrix.However,the scaffold materials currently used for wound regeneration are mostly aimed at improving their biocompatibility,ignoring the coordination between the materials and various physiological signals in the wound repair microenvironment,thereby limiting the efficiency of wound repair.The wound regeneration process contains a variety of physiological signals,and these physiological signals play an important role in the wound regeneration process,which determines the efficiency of wound regeneration.Among them,physiological electrical signals can promote wound tissue regeneration by regulating cell behavior.Excessive reactive oxygen species/free radicals will induce oxidative stress,leading to oxidative damage at the cell level and injury impeding regeneration.Therefore,designing a wound dressing that can coordinate physiological signals provides a new idea for accelerating wound regeneration.Based on mussel chemistry,this paper designs a multifunctional bioactive scaffold with good mechanical properties,electrical activity and anti-oxidation.The relationship between the physical and chemical structure of the scaffold and its mechanical properties,electrical activity and oxidation resistance was investigated.The effect of the physiological response of the scaffold on tissue regeneration was also explored.The main research content includes the following two parts:First,a natural polymer scaffold with good bioactivity was prepared by biomimetic mussel adhesion chemistry.Reduced graphene oxide(pGO)with good electrical conductivity is prepared by dopamine reduction and modification of graphene oxide.In addition,dopamine can also be modified on the surface of graphene oxide while reducing graphite oxide.Rich functional groups such as catechol and amino groups can also improve the dispersibility of pGO.Then,pGO was dispersed into an aqueous solution of chitosan(CS)and silk fibroin(SF),and a pGO-CS/SF composite scaffold having good electroactivity and oxidation resistance was prepared by double cross-linking and freeze-drying techniques.The introduction of pGO can be used as a nano-enhancer to enhance the mechanical properties of the pGO-CS/SF scaffold.Meanwhile,due to the good conductivity and oxidation resistance of pGO,the pGO-CS/SF scaffold can be imparted with good conductivity and good scavenging ability for DPPH radicals and hydroxyl radicals.Second,the response between the pGO-CS/SF composite scaffold and physiological signals during wound regeneration was explored by cell experiments and animal experiments.C2C12 cells are seeded on materials and simulated by high-throughput electrical stimulation devices.Cell experiments have shown that electrical signals can promote the proliferation and orientation of C2C12 cells.Anti-cellular oxidation experiments were performed by macrophages(RAW 264.7).The results showed that the pGO-CS/SF scaffold can effectively remove reactive oxygen species(ROS)in the environment and reduce oxidative stress in cells.The full-thickness skin regeneration experiment also showed that the pGO-CS/SF scaffold has excellent wound regeneration ability due to good electrical activity and antioxidant properties.