In Vitro Studies On The Degradation Of Cellulose Absorbable Hemostatic Products

Cellulose absorbable hemostatic products are widely applied in clinical and their safety has raised increasingly concerns from related approval department,doctors and patients.Their complete degradation time is one of the key factors in clinical application.To improve safety of absorbable hemostatic products,it is necessary to adjust complete degradation time of products,establish a rapid and accurate detection technology.At present,there is a lack of systematic research on the degradation,the separation and analysis methods of biodegradable materials.Therefore,this study intends to set up scientific and effective evaluation system of hemostatic material,improve shortcomings and deficiencies of the current standards.In the first part,background and significance of the work were introduced.In the second part,oxidized degredation conditions in vitro of cellulose absorbable hemostatic products were explored and device of dynamic degradation was designed to evaluate their degredation performance.3% hydrogen peroxide was optimized as degradation solution,device of dynamic degradation can better evaluate degredation performance and provide ideas to establish a rapid,accurate and effective evaluation methods for the evaluation of other materials.In the third part,a new method for determining complete degradation time ofsoluble hemostatic products was established.The current weight loss method was optimized by using dialysis bag combined with assay of reducing sugar.The correlation coefficient between percentage of weight loss and cumulative content of reducing sugar was 0.957,which illustrated high correlation with each other.Hence dialysis bag combined with assay of reducing sugar is capable of evaluating the degradation endpoint of soluble hemostatic products in vitro.The method also provides a way for the evaluation of degradation of other degradable biomaterials in vitro.In the fourth part,GPC(gel permeation chromatography)was used to monitor the degradation process of materials and other information.The degradation endpoint of cellulose absorbable hemostatic products was determined by testing molecular weight in the dialysis bag at different time.This method can evaluate endpoint of cellulose absorbable hemostatic products,as to whether the method is applicable to other materials need to be further verified.In the fifth part,SEM and FT-IR were used to analyse functional groups and morphology changes between degradation products and original cellulose absorbable hemostatic products.The functional groups analysis results showed little changes but morphology analysis results showed obvious changes between degradation products and original cellulose absorbable hemostatic products.In the sixth part,MTT method was used to assess the cytotoxicity of two cellulose absorbable hemostatic products' solutions and degradation solutions.The results showed that degradation products had more serious influence on cells andwould provide new ideas to evaluate safety of cellulose absorbable hemostatic products.