| Objective: Commercial hemostatic materials generally present limitations such as inducing inflammatory reaction,lack of antibacterial activity and limited hemostatic effect,which seriously restrict their clinical application.In this study,a hemostatic sericin dressing with outstanding antibacterial and procoagulant activity is designed and prepared to effectively control traumatic hemorrhage and prevent infection,therey improving the quality of prehospital management and clinical treatment for traumatic hemorrhage.Methods: Sericin-methacryloyl/Ag cryogel(SMC@Ag)dressing was prepared by freezing polymerization of methacryloyl modified sericin,a major component extracted from silkworm cocoons,and in-situ sericin reduction of silver ions.SMC@Ag was characterized and analyzed by scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR).Meanwhile,the biodegradability,mechanical strength,water and blood absorption swelling behavior of SMC@Ag were tested to verify the biological application feasibility of the material.The SMC@Ag treatment effect on in vitro blood coagulation process was investigated by testing in vitro whole blood coagulation time(CT),blood-clotting index(BCI)and thromboelastography(TEG).Models of rat liver injury,tail amputation,and femoral artery injury were established,respectively,to evaluate the animal hemostasis feasibility of SMC@Ag dressing.The SMC@Ag treatment effect on blood coagulation pathway was analyzed through testing four blood coagulation indicators(prothrombin time,activated partial thromboplastin time,fibrinogen concentration and thrombin time),activated coagulation factor Ⅻ(FⅫa),thrombin(FⅡa)and fibrinopeptide A(FPA).The effects on platelet adhesion and activation were evaluated by fluorescence staning(FITC-PI,PEa CD61,FITC-a CD62 P and FITC-Annexin V)after SMC@Ag treatment.The in vitro antibacterial activity of SMC@Ag was evaluated against Staphylococcus aureus(S.aureus),methicillin-resistant Staphylococcus aureus(MRSA)and Escherichia coli(E.coli).And in vivo rat infection models were further constructed to verify the feasibility of SMC@Ag dressing for post-traumatic infection prevention.Whereafter,the biocompatibility of SMC@Ag was investigated.CCK-8 assays were performed to determine the cytotoxicity of SMC@Ag to mouse fibroblast cells(L929)and human hepatocytes(L02).FITC-PI and DAPI co-staining immunofluorescence assays and RT-qPCR tests were conducted to evaluate the immune compatibility of SMC@Ag to murine macrophage-like cells(RAW264.7).Hemolysis assays were performed to estimate the blood compatibility of SMC@Ag.Furthermore,SMC@Ag was implanted in vivo to assess the risk of thrombosis and H&E and CD68 immunohistochemical staining were performed on the tissues around the implantation sites to verify the in vivo biocompatibility.Results: SMC@Ag has an interconnected macroporous structure and could rapidly absorb a large amount of blood to concentrate.The introduction of silver nanoparticles enhances the mechanical strength of sericin cryogel.SMC@Ag could withstand 0.2 MPa stress and the compression strain reaches 85%.SMC@Ag has excellent procoagulant activity,which could significantly shorten the whole blood coagulation time and reduce the blood coagulation factor reaction time and blood clot formation time by promoting the generation of FⅫa,thrombin and FPA,and facilitating the adhesion and activation of platelets.Moreover,the excellent biocompatibility of SMC@Ag is revealed.And it exhibits better hemostasis performance and antibacterial activity than commercial gelatin sponge in vivo.Conclusion: In this study,a dual functional antibacterial hemostatic dressing SMC@Ag is successfully fabricated,which could promote hemostasis by absorbing blood rapidly and facilitating the activation of coagulation pathway and platelets.This dressing also exhibits excellent mechanical property and biocompatibility,and is suitable for clinical trauma hemostasis and infection prevention. |
PDF Full Text Request