Research On The Preparation And Characterization Of CS/PVA-alginate Composite Hemostatic Dressing

Traumatic bleeding occurs now and then in our daily life.In wars,traffic accidents and natural disasters,excessive hemorrhage is one of the key factors leading to death.The hemostatic dressing is an important material to effectively prevent death from excessive loss of blood.However,the traditional hemostatic dressing has limitations,such as poor effect in hemostasis and inability to stop bleeding in the opposite different wound.Therefore,it is of great significance to develop a hemostatic dressing with excellent hemostatic efficacy,certain functionality and easy to use.The ocean contains abundant resources in storage.Alginate and chitosan extracted in large quantities from marine organisms have good hemostatic effect and biocompatibility.In addition,chitosan is widely used in the field of antisepsis because of its excellent antibacterial effect.Therefore,the preparation of hemostatic dressings with alginate and chitosan has broad research prospects.This article used sodium alginate and chitosan as raw materials to prepare a composite hemostatic dressing.Alginate-containing polyvinyl alcohol hemostatic sponges and chitosan nanofiber membranes with antibacterial effects were respectively prepared by thermoforming and electrospinning techniques.The medical hot-melt pressure-sensitive adhesive is used for bonding to prepare a hemostatic dressing with antibacterial properties.First of all,the best technological conditions for preparation of polyvinyl alcohol sponge were studied.Sponges with higher porosity,lower density and stronger liquid absorption were prepared.The single-factor experiment determined the optimal amount of sodium alginate,and prepared hemostatic sponge under this condition.The in vitro coagulation test showed that it had excellent effect to stop bleeding.Secondly,different types and proportions of polyvinyl alcohol and chitosan were mixed to prepare electrospinning nanofiber membranes.The molecular weight of polyvinyl alcohol and the viscosity of chitosan were determined.Under the optimal spinning conditions,the nanofiber membrane had good antibacterial properties.Experiments showed that polyvinyl alcohol with molecular weight of 85000,alcoholysis degree of 90% and chitosan with viscosity of 200-400 mPa.s and deacetylation degree of 95% had good spinning effect.After that,the best spinning process of nanofiber membrane was explored.The single-factor experiment and the orthogonal experiment determined the best technology of the factors such as the applied voltage,the receiving distance and the spinning liquid flow in the electrospinning process.The process parameters are: voltage 21 kV,receiving distance 13 cm,spinning solution flow 0.4mL/h.The surface of the nanofiber membrane prepared in this process is smooth and uniform,and the diameter difference is small.Cross-linking nanofiber membranes with glutaraldehyde vapor improved its waterproof performance and scanning electron microscopy observations showed that there is no significant change in nanofibers before and after crosslinking.The antibacterial test was carried out on the crosslinked nanofiber membrane,and the results showed that the membrane had excellent antibacterial effect.Finally,the hemostatic sponge containing sodium alginate was bonded to the chitosancontaining nanofiber membrane with hot-melt pressure-sensitive adhesive,and a CS/PVA-alginate composite hemostatic dressing with antibacterial effect was successfully prepared.