Preparation Of Shell Powder And Chitosan Composite Hemostatic Materials By Supercritical Fluid Technology

Chitosan is a kind of good natural biocompatible hemostatic material,shell type containing a clotting factor,a hemostasis effect of the composite produced two further study.In this paper,we prepared the chitosan hemostatic sponges and their combination with powders（shell powder/chitosan sponges,pearl powder/chitosan sponge）by supercritical carbon dioxide（sc-co2）assisted method.Further,the hemostatic effect and biocompatibility of the prepared sponges are evaluated and the highlights of the research are summarized as follows:1.The composite sponges are prepared by the sc-co₂ foaming method maintained at 25 Mpa,2h,and 40℃.The structural propertiese,water absorption and porosity of designed sponges and its effects such as,coagulation time in vitro and whole blood coagulation are investigated.The prepared materials have uniform pores and high cross-linking degree,which have a significant influence on porosity and water absorption.2.Biocompatibility tests of include hemocompatibility and acute toxicity in mice are investigated.The results demonstrated that the extracts of prepared sponges resulted in excellent hemocompatibility by blood routine test;and after 72 hours of intraperitioneal injection in mice had ensured no acute toxicity and their liver sections were normal.3.The mechanism of hemostasis of all the synthetic sponges is discussed by the determination of partial clotting time（APTT）,prothrombin time（PT）and thrombin time（TT）.However,the results indicated that the action of composite sponges is partially dependent on physiological hemostasis.4.The hemostasis effect of all the designed combinations is investigated by using various models such as a femoral artery;tail trauma and liver of Kunming mice.In femoral artery,the hemostatic time of chitosan sponge,chitosan-shell powder sponge and chitosan-pearl powder sponge recorded was 64.3 ± 15.2s,44.7 ± 14.0s,50.2 ± 15.2s,respectively.In trauma model,the reading were 82.1 ± 17.7s,48.6 ± 11.0s and 51.6 ± 10.2s respectively.In liver,the recordings were 82.1 ± 17.7s,62.3 ± 4.0s and 70.2 ± 10.2s,respectively.In addition,the hemostatic time was significantly less than Avitene sponges and medical hemostatic gauze.Conclusions: The shell powder/chitosan composite hemostatic material prepared by supercritical fluid foaming technology has excellent biocompatibility and has significant hemostasis effect,and it is expected to be the best choice in treating clinical hemostasis...