Research On The Preparation And Hemostatic Mechanism Of Hemostatic Materials Through Injury

Rapid hemostasis for non-compressible bleeding injuries such as penetrating injuries in emergency first aid is the key to saving lives.The existing hemostasis system mainly focuses on developing different hemostatic devices for different anatomical locations,which is narrowly adapted and has poor hemostatic effect,and also ignores the multiple needs of antibacterial and pain relief during the hemostasis process,which becomes the key to limit the emergency treatment.Based on the previous research on hemostatic system,this project uses chitosan as the main raw material to prepare chitosan hemostatic sponge cross-linked with sodium tripolyphosphate to improve the poor mechanical properties of single chitosan,and then grafted with3,4-dihydroxyphenylacetic acid to prepare chitosan composite hemostatic sponge to increase its We designed and constructed an in vivo hemostatic system with multiple coupling properties.It is suitable for multiple anatomical locations and breaks the bottleneck of the current pre-hospital emergency hemostasis system.Through in vivo and ex vivo biological evaluation,we will analyze the structure-effect relationship of the hemostatic system and the mechanism of action in pre-hospital emergency.The specific experimental methods and results are as follows:（1）In this paper,chitosan,which has excellent hemostatic properties and can promote wound healing,was firstly used as a hemostatic material.Columnar chitosan samples of different sizes were prepared by freeze-drying method and medical syringe,and chitosan was treated with sodium tripolyphosphate（TPP）as an ionic cross-linking agent,as it contains PO-Na⁺group and chitosan-NH³⁺group dissolved in acetic acid to form intramolecular and intermolecular cross-linkages,and The physicochemical characterization and biological properties were characterized,and the results showed that the chitosan hemostatic sponges cross-linked by sodium tripolyphosphate could effectively improve the disadvantages of chitosan inability to prepare larger concentrations of solutions and poor physical and mechanical properties,and the optimal conditions are chitosan concentration of 20mg/ml and a crosslinking ratio of 10%NaCl+1%TPP.（2）Since most binders have poor adhesion to tissues and mucous membranes,many scholars have found that 3,4-Dihydroxyphenylacetic acid（HCA）can form strong covalent and non-covalent bonds with various organic/inorganic/metal materials by adhering to the surface of various substrates under wetting conditions.In this paper,the strong covalent and non-covalent bonds are formed by EDC/NHS coupling reaction to graft catechol groups on the structure of controlled cross-linked chitosan hemostatic sponge samples to obtain catechol-modified chitosan hemostatic sponge（CMCHS）,and to characterize its physicochemical and biological properties.The results show that compared with CHS,CMCHS exhibits a richer and more uniform pore structure,and the pore structure of CMCHS is more uniform and continuous when the ratio is HCA₃.All physicochemical properties suggest that CMCHS has the potential to be used for incompressible traumatic bleeding through injuries and lays the foundation for its subsequent hemostatic applications.（3）In this paper,we demonstrated that CMCHS can significantly accelerate whole blood coagulation,increase the degree of platelet and red blood cell adhesion,and has no cytotoxicity and good biocompatibility by performing whole blood coagulation,red blood cell adhesion test,platelet adhesion test,hemolysis and cytotoxicity test on CMCHS.In a rabbit liver model,CMCHS significantly shortened hemostasis time and reduced blood loss.The current study has important implications for the use of chitosan composite hemostatic sponges for hemostasis in non-compressible wounds such as penetrating wounds and demonstrates its feasibility for future clinical applications.