The Basic Study Of Biodegradable Trachea Stent

Purpose1. To design a kind of biodegradable trachea stent with PLLA and HA meterials by the technology of CAD(computer aided design),and to test its mechanical properties in the use of trachea stent.2. To evaluate the biocompatibility of the PLLA/HA materials stents,and study the biodegradation property of the these trachea stents in vitro and in vivo for further study and application.Materials and Methods1. A kind of stent was designed with PLLA and HA,and the mechanical properties were tested.2. A hydrolysis test was performed in PBS in vitro, and these PLLA/HA materials stents were implanted in 4 dogs' tracheas for in vivo study. The histopathological changes of the tracheas were observed,and biodegradation property was studied via molecular weight changes and weight loss ratio.Results1. The stents were prepared with PLLA/HA materials from 20 mm to 26mm in diameter,80mm in length,and the mechanical properties were tested.2. The histopathological observation found no significant inflammatory reaction for 4 weeks,8 weeks,12 weeks and 16 weeks after the stents implantion.The Mv in vivo decreased more than that in vitro,and the difference between them was significant; also the weight loss ratio decreased quickly than in vitro,but it kept the pattern of the biodegration of PLA.Conclusion1. The mechanical properties of the PLLA/HA materials stents are available for the dogs' tracheas for futher study.2. These PLLA/HA materials stents have good biodegrdation property and biocompatibility in dogs' tracheas,and they are new kinds of materials in the use of trachea stent.