Study On The Preparation And Property Of PDO Intravascular Stent

With the improvement of modern living standards,cardiovascular disease has become a major threat to human health.Stent implantation through PTCA(Percutaneous transluminal coronary angioplasty)and PCI(percutaneous coronary intervention)is currently the effective means of cardiovascular disease reconstruction which caused artery stenosis.The curative effect of first generation of metal stents and second generation drug-coated stents treating coronary heart disease has confirmed and widely used in clinical.But as a permanent stents retention in the body easily lead to a lot of inflammation and even cause vascular restenosis and other issues.To the issues,this paper is researching on the biodegradable material stent.As a kind of temporary support,it can be degraded into non-toxic molecules gradually after vascular injury healing.The molecules can be absorbed and excreted with the blood circulation.At the same time the biodegradable stent also as an anti-irritant anti-allergy drug carriers,which has become the research forefront and hot point of cardiovascular disease treatment in domestic and overseas.This project proposed to study on basic materials and the structure characteristics of the biodegradable stent to discuss the mechanical properties and degradation performance.Absorbable material PDO monofilament has been chosen to prepare intravascular stents.The apparent morphology,degree of crystalline and orientation,mechanical properties and bending stiffness and other basic properties were investigated.The in vitro degradation test shows that PDO monofilament has a slowly degradation performance and highly strength retention.16 kinds of hand-braided intravascular stents were produced with four different diameters of PDO monofilament.The structure of stents have characterized including inside diameter,outside diameter,thickness,comprehensive in support of porosity,axial shortening and etc.The PDO intravascular stents can meet the application requirements of the porosities.Through study all aspects of performance especially radial support to optimize the mechanical characteristics of stent.The pre-simulation experiments confirmed the method of radial compression testing.Compression-recovery curve,radial compression force,strength retention rate,the elastic recovery rate have been discussed to analysis the radial compression performance of the PDO intravascular stents.Combined with the actual demand of the hospital implanted rationality analysis,compare the degradation performance of preferred PDO intravascular stent in vitro degradation experiments.The research indicates that the PDO degradation intravascular stent has the optimized structure,excellent mechanical properties and degradation.Consequently,this study will provide credible data for our country to develop and produce with independent intellectual property rights of the biodegradable stent products.