Abstract:

BACKGROUND: At present, the main research fields about coronary stents are the whole degradation biological materials with high biocompatibility and drug controlled release systems.
OBJECTIVE: To evaluate the safety after the two novel biodegradable stents implanted in coronary arteries in porcine models.
METHODS: The normal fully biodegradable stents were made up of the poly-L-lactide and the antiproliferative drugs paclitaxel, and the novel biodegradable stents were added in amorphic calcium phosphate at the basis of normal biodegradable stents. (1) Five normal fully biodegradable stents were randomly implanted into the coronary arteries of five porcines, and five novel biodegradable stents were randomly implanted into the coronary arteries of the remaining five porcines by coronary angiography. The blood biochemistry and C-reactive protein levels were measured pre-operation and at 28 days after operation. Coronary angiography was utilized to observe the lumen unobstructed at 28 days after surgery. (2) Under a microscope, seven normal fully biodegradable stents and seven novel biodegradable stents were implanted into right external iliac arteries of 14 rabbits. Blood urea nitrogen and creatinine levels were measured before surgery and at 28 days after operation.
RESULTS AND CONCLUSION: At 28 days after operation, there were no significant changes in porcine glutamic-pyruvic transaminase, aspartate aminotransferase, triacylglycerol, total cholesterol, low density lipoprotein and C-reactive protein levels compared with that before operation, but urea nitrogen and creatinine levels were significantly higher than that before operation (P < 0.05). The result of coronary angiography showed that no in-stent thrombosis or stenosis was detected in either group. There was no significant difference in urea nitrogen and creatinine levels in both groups. These results suggested that it is safe and compatible after the two novel biodegradable stents implanted in coronary arteries of porcine models, and the stents had good histocompatibility.

Key words: biocompatible materials, drug-eluting stents, coronary vessels, calcium phosphates