Study On Preparation And Properties Of Hemostatic And Antibacterial Nasal Packing Materials

The incidence of nasal diseases is high in the population,and patients with severe rhinitis,sinusitis,and nasal tumors require surgery with nasal endoscopy.The nasal mucosa is rich in blood vessels,which is easy to cause bleeding after surgery.Hemostatic sponges are usually used to fill the nasal cavity to stop bleeding,but there are a large number of bacteria in the nasal cavity,and there is a risk of postoperative infection.The current hemostatic sponges on the market do not have antibacterial properties and are not comfortable enough to bring good experience to patients.In this paper,through the screening of the pre-freezing process and the sponge substrate,gelatin and chitosan are selected as the sponge substrate,and liquid nitrogen flash freezing is the pre-freezing process.Gelatin/chitosan(GE/CS)sponges with various formulations were prepared by prefreezing and freeze-drying in liquid nitrogen under certain conditions.The changing trend of sponge properties with cross-linker concentration and crosslinker concentration was investigated.Quaternary ammonium 1,2-epoxypropyl dimethyldodecyl ammonium chloride(EPQA)modified gelatin was synthesized.The sponge prepared by modified gelatin/chitosan had excellent water absorption,degradability,biocompatibility,hemostatic properties,and antibacterial property.1.Use-18 refrigerator,-50 lyophilizer pre-freezing chamber and liquid nitrogen quick-freezing to pre-freeze a variety of sponge materials,and select liquid nitrogen as the optimal pre-freezing process according to the sponge yield and appearance uniformity.Gelatin/sodium alginate(GE/SA),GE/CS and chitosan/sodium alginate(CS/SA)sponge solutions were prepared by using different cross-linking segments.The sponges were pre-frozen in liquid nitrogen and freeze-dried.GE/CS sponge has a uniform texture,a water absorption rate of 64.88 times,and a degradation rate of about 30% in three days in vitro,which can meet the clinical requirements.Therefore,GE/CS was selected as the sponge substrate.2.To explore the effects of GE/CS ratio and genipin dosage on sponge properties.The basic properties,biocompatibility and in vitro hemostatic properties were determined.The study found that with the increase of genipin dosage,the apparent density and compressive strength of the sponge increased,while the porosity,water absorption,swelling degree,pore size and degradation rate decreased.The higher the content of chitosan,the stronger the water absorption ability and swelling ability of the sponge,and the better the hemostatic effect.However,the high content of chitosan leads to poor mechanical properties of the sponge after water absorption,easy to break,and slow degradation rate.The hemolysis rate of GE/CS sponges with different formulations was lower than 5%,and the cell activity was higher than 80%,which met the medical requirements.In order to ensure the performance of the sponge,the concentration of genipin should be 0.006%-0.018%,and the mass ratio of GE/CS should be 3:9-7:5.Under these conditions,the sponge water absorption rate should be 50.64-67.9 times,the degradation rate of three days should be more than 30%,the coagulation index in vitro is 24.29%-62.64%,and the swelling degree is about 200%.The mechanical strength was stable.3.EPQA was synthesized with EPichlorohydrin and N,Ndimethyldodecylamine to prepare quaternary ammonium gelatin/chitosan(EPQA-GE/CS)antibacterial sponge.The conversion rate of EPQA was78.38%,and the amino conversion rate of gelatin was 37.07%.The water absorption rate of different ratios of EPQA-GE/CS antibacterial sponges was more than 50 times,and the highest was 82.83 times.The degradation rate was more than 30% in three days,and the highest degradation was 53.77%.The BCI coagulation index in vitro was between 25.57% and 65.26%,and the hemostasis effect was good.When the mass ratio of EPQA-GE to CS was less than 5:7,the hemolysis rate of the sponge was less than 5%,the relative cell activity was higher than 70%,and the biocompatibility was good.When the ratio of EPQAGE to CS was 3:9,the inhibition rate of S.aureus and E.coli was 99.9%,which showed a good antibacterial property.4.EPQA-GE/CS antibacterial sponge was used to stop bleeding in rabbit nasal septal mucosal trauma animal experiments.Compared with medical PVA sponge,the bleeding volume was reduced by 67.34%,and the hemostasis time was reduced by 31.03%.It has good biocompatibility and can prevent wound infection.