In Vitro Degradation Study on Braided Degradable Ureteral Stent

摘要

The biodegradable ureteral stents are investigated to retain their supporting properties for defined periods.They negate secondary removal surgery and avoid other complications that conventional biostable stents bring to us.But their mechanical and degradation properties should be improved so as to function well and then gradually degrade.A new braided biodegradable ureteral stent composed of PGA (Polyglycolic acid) and PGLA (Copolymer of polyglycolic and polylactic acid) multifilaments was evaluated in vitro in this study.In vitro degradation was performed in artificial urine and human urine respectively with the temperature of 37°C and the pH of about 5.8.The mechanical properties and morphology were observed at different degradaing time intervals of 0,1,2,3,4,5 weeks.Both the biodegradable and biostable stent and two kinds of culture solutions were compared.In human urine,the mechanical properties of braided biodegradable stent could meet the demand of clinical application in the first 10 days and then gradually degraded.The degradation in human urine which is closer to the in vivo environment was 1 week faster than that in artificial urine with the degradation product of quiet little fragments and finally powder which has a smaller possibility of obstruction.