Prepartation And Prorerties Of Chitosan-based Composite Sponge Dressing

Polysaccharide-based materials are widely used in the field of hemostasis,due to their advantages,such as wide source,biodegradability,good biocompatibility and low immune response.Among natural polysaccharides,chitosan with positive charge of the amino group can promote adhesion of red blood cells,induce platelet aggregation/activation and promote hemostasis.Therefore,the development of high-performance chitosan-based hemostatic materials is a research hotspot in the field of hemostatic materials.Sodium alginate is a natural polysaccharide with good biocompatibility and hydrophilicity.Negative charges on the surface of alginate can induce the activation of factor XII and accelerate hemostasis.The first part of this paper is to prepare a cross-linked porous hemostatic sponge based on the cross-linking of chitosan and sodium alginate.A polysaccharide macromolecular cross-linking agent(SA-CHO)was prepared by the oxidation treatment of sodium alginate,and a chitosan/sodium alginate composite sponge(CSH-SA)was prepared by the Schiff base reaction between the aldehyde groups of sodium alginate oxidation and the amino groups of chitosan.The hemolysis test and in vitro dynamic whole blood coagulation test demonstrated that CSH-SA sponge possessed good blood compatibility and in vitro coagulation effect.Rat femoral artery trauma model further confirmed the excellent in vivo hemostatic ability of CSH-SA sponge.The positive charges of chitosan can inhibit bacterial growth.However,because of the poor antibacterial effect of large-molecular-weight chitosan and the high cost of small-molecular-weight chitosan,the antibacterial effect of pure chitosan normally cannot meet the clinical needs.Based on the first part work,the second part is to firstly prepare a wide-spectrum antibacterial agent,quaternary ammonium quaternized polyethyleneimine(QPEI),through the reaction of polyethyleneimine and bromohexane.Then,a chitosan-based antibacterial sponge(CSH-P)was prepared through the ternary cross-linking of SA-CHO,QPEI and chitosan.The antibacterial experiment confirmed that CSH-P sponge possessed excellent antibacterial effect against S.aureus and E.coli.MTT cytotoxicity experiment showed the low cytotoxicity,excellent antibacterial property of CSH-P sponge with QPEI addition amount of 2%.The results demonstrated that CSH-P could serve as a medical antibacterial dressing to be applied in clinical practice.In summary,two chitosan-based composite sponge dressings were prepared in this paper.Chitosan-based composite hemostatic sponge dressings have highly effective hemostatic properties and excellent blood compatibility.Chitosan-based composite antibacterial sponge dressings have good properties.The antibacterial properties and no obvious cytotoxicity are expected to be applied clinically.