ABSTRACT
Objective To investigate mechanical performances of two different drug eluting stents (DES) during compression process, so as to provide a scientific guideline for design of DES. Methods Using Solidworks, two kinds of stent models, namely the common DES without slots in outside surface (Stent I) and the targeted DES with slots in outside surface (Stent II) were established, respectively. The important mechanical properties of the two stents during compression process, such as rebound ratio of radial contraction, rebound ratio of axial contraction, the inhomogeneity of compression and the distribution of residual stress, were analyzed by ABAQUS. Results With the same outer radius, the difference values of rebound ratio of radial contraction, rebound ratio of axial contraction and inhomogeneity of compressing for the two stents were 0.07%-0.12%, 0.016%-0.033% and 0.013 %-0.048%, respectively; there was a bigger low-stress area on the support of Stent II. Conclusions Compared with the traditional DES, the targeted DES could maintain the same mechanical performances while reducing drug-loading capacity, which shows a good prospect in clinical application of the treatment for cardiovascular stenosis diseases.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of SSd on lipid peroxidation during experimental hepatic fibrosis progression.</p><p><b>METHOD</b>The experimental models of hepatic fibrosis were induced by intraperitoneal injection of dimethylnitrosamine (DMN) on rats. SSd was administered by intraperitoneal injection for 4 weeks. Serum was analyzed for alanine and aspartate aminotransferase (ALT and AST), hyaluronic acid (HA), laminin (LN), collagen IV (IV-C), malonaldehyde (MDA) and superoxide dismutase (SOD) activities. Liver samples were measured for MDA contents and SOD activities in normal group, model group and SSd group.</p><p><b>RESULT</b>SSd significantly decreased ALT and AST activities and lowered HA, LN and IV-C contents. It enhanced SOD activities in liver, while reduced MDA contents both in serum and liver.</p><p><b>CONCLUSION</b>SSd has obvious effects of protecting hepatocytes and resisting hepatic fibrosis, and the mechanism may be associated with its anti-lipid peroxidation effect.</p>