Objectives To observe the impact on endothelial repair of structure and function after novel fully biodegradable drug-eluting stent implanted in mini-pigs coronary arteries.
Methods A total of 10 biodegradable stents [fully biodegradable drug-eluting stent (FBS, n = 5), novel fully biodegradable drug-eluting stent (NFBS, n = 5)] were randomly implanted into the coronary arteries of 10 pigs (one stent for one pig). Twenty-eight days later, coronary angiography was utilised to observe the lumen unobstructed and general properties of all stents. Then the pigs were sacrificed. Their coronary arteries with the stents inside were taken out. Histomorphometric and histopathological analysis were performed to evaluate endometrial hyperplasia. Immunohistochemical assay was applied for expression of CD31 and eNOS.
Results No in-stent thrombosis and parietal were detected in either group. At 28 days follow-up, haematology showed the VEGF level in NFBS group was higher than that in FBS group [(309.86 ± 49.37) pg/ml vs. 222.04 ± 55.16) pg/ml, P < 0.05], and the NO level in NFBS group was higher than that in FBS group [(176.15 ± 20.63) µmol/L vs. 129.96 ± 9.52) µmol/L, P < 0.05]. Immunohistochemistry showed that eNOS protein expression in NFBS group was significantly greater than that in FBS group (38.53 ± 4.25 vs. 27.53 ± 3.55, P < 0.01), and CD31 protein expression in NFBS group was greater than that in FBS group (29.40 ± 3.84 vs. 19.78 ± 3.50, P < 0.05).
Conclusions The novel fully biodegradable drug-eluting stents show sufficient biocompatibility, and it can promote the recovery of endothelial structure and function. Therefore, the novel fully biodegradable drug-eluting stents can effectively promote the process of endothelial repair.