Preparation And Hemostatic Performance Of Composite Materials Based On Chitosan And Diatomite

Excessive bleeding causes a large part of deaths in wars and accidents.It is necessary to prepare a hemostatic material with excellent performance and low cost by a facile strategy.Highly biocompatible and efficient hemostatic sponges(CS/SA/ADia)were prepared by using chitosan(CS),sodium alginate(SA)and aminated diatomite(ADia)as raw materials.Firstly,ADia was prepared with the"one-step method"by using diatomite(Dia)and(3-aminopropyl)triethoxysilane(APTES)as raw materials.The chemical structure and morphology of ADia were studied by using Fourier infrared spectrometer(FTIR),X-ray diffractometer(XRD),X-ray photoelectron spectrometer(XPS)and field emission scanning electron microscope(SEM),respectively.The grafting amount and surface Zeta potential change of ADia were measured by thermogravimetric analyzer(TGA)and dynamic light scattering instrument(DLS),respectively.The results show that the surface amination did not affect the surface morphology,the structure,and the crystallinity of diatomite.The surface grafting amount of amino groups is about 1.5 wt%,and the surface Zeta potential of diatomite before and after modification from-30.4.m V increases to+3.3 m V.Subsequently,CS/SA/ADia was prepared by freeze-drying and Ca²⁺cross-linking by using the blend of CS,SA and ADia.The chemical structure,surface morphology,mechanical properties and the ADia composite stability of CS/SA/ADia were characterized by FTIR,SEM,enzyme-labeled instrument and tensile testing machine respectively.The test results show that CS/SA/ADia is of a typical sponge skeleton structure,where ADia can be stably compounded in CS/SA/ADia to enhance its mechanical properties.Through in vitro hemolysis experiments,cytotoxicity experiments and subcutaneous implantation experiments in mice proved that CS and SA made CS/SA/ADia well compatibility at the blood,in vitro and in vivo levels,respectively.In vitro whole blood coagulation experiments and mice liver hemostatic experiments proved that CS/SA/ADia could quickly stop bleeding.As the content of ADia increases,the hemostatic effect is improved.CS/SA/ADia exerts hemostasis by intrinsic pathway was proved by measuring the prothrombin time(PT)and activated partial thromboplastin time(APTT).In order to avoid the traditional powdered hemostatic material enter the human body from the wound,causing uncontrollable thrombosis.Hemostatic microspheres(CS/ADia/Dpa/TBA)were prepared by the alkaline precipitation and tert-butanol(TBA)replacement method,by using CS,dopamine(Dpa)and ADia as raw materials.The chemical structure,surface morphology and internal structure of the CS/ADia/Dpa/TBA were characterized by FTIR and SEM,respectively.The experimental results show that CS/ADia/Dpa/TBA is of multiscale hierarchical porous structure and great water absorption rate,which can be controlled by the concentration of TBA.In vitro hemolysis experiments and cytotoxicity experiments proved that CS/ADia/Dpa/TBA is of good biocompatibility.In vitro whole blood coagulation experiments and hemostatic experiments in mice liver proved that the hemostatic microspheres obtained by 30 wt%TBA replacement solution are of the best hemostatic effect.CS/ADia/Dpa/TBA exerts hemostasis by intrinsic pathway was proved by measuring the prothrombin time(PT)and activated partial thromboplastin time(APTT).