The preparation of biodegradable intravascular stent and the studies of its properties / 中华放射学杂志

ABSTRACT

Objective To investigate the preparation of a biodegradable intravascular stent (BIS) with poly-l-lactic acid (PLLA), and to evaluate its physical and mechanical properties, as well as its biocompatibility. Methods The study of this BIS was first prepared by PLLA with molecular weight of 100 000 unit as the strut, and then the micro-porous structure was fabricated and the film was coated at the struts. Following the solidified shaping of BIS, the primary physical and mechanical properties of the BIS were tested, and 22 zigzag type BISs were implanted into the aorta and iliac arteries of 11 canines, then they were euthanized according to a fixed timetable for histopathological assessment. Results Two types of BIS (spiral and zigzag) were prepared, and the strut diameter of the BIS was 0.1-0.6 mm, stent diameter of BIS was 6-15 mm, and stent length was 30-80 mm. Of this BIS, the radial strength was 1.6-2.0 kPa (1 kPa=7.5 mm Hg), the dilatable rate was 6.0-6.5, the shortening rate was smaller than 8%-10%, and the proportion of stent surface area to open surface area was 0.16-0.18 (