title: Poly-l-lactic acid/amorphous calcium phosphate bioabsorbable stent causes less inflammation than poly-l-lactic acid stent in coronary arteries.
abstract: OBJECTIVE
  Poly-l-lactic acid (PLLA) based bioabsorbable stents with or without amorphous calcium phosphate (ACP) were implanted and compared the inflammation in coronary arteries.
  
  
  METHODS
  6 PLLA and 6 PLLA/ACP based paclitaxel-eluting stents were randomly implanted into the coronary arteries of 12 healthy mini-pigs. The segments with stent were used to evaluate inflammation score and endothelialization score by hematoxylin-eosin staining.
  
  
  RESULTS
  At the 28th day after stent implantation, no in-stent restenosis or stent thrombosis was found in both PLLA and PLLA/ACP group. Histological analysis indicated that the inflammation score in PLLA/ACP group was less than that of in PLLA group (2.20±0.42 vs. 2.80±0.48, P<0.05). Consist with that, the expression of NF-κB was lower in PLLA/ACP group. The results from immunohistochemistry showed that the expressions of endothelial nitric oxide synthase (eNOS) and CD 31 in PLLA/ACP group were dramatically higher than those in PLLA group respectively. The serum levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in PLLA/ACP group were significantly higher than those in PLLA group respectively (509.86±49.37 pg/ml vs. 322.04±35.16 pg/ml and 139.46±7.52 μmol/L vs. 29.55±16.55 μmol/L, P<0.05).
  
  
  CONCLUSIONS
  The application of ACP helps to reduce the inflammation caused by PLLA, and is also helpful in endothelial formation and function for PLLA-based bioabsorbable stent.
authors: Department of Emergency, Yantaishan Hospital Yantai 264000, China.
authors: Lingting
authors: L
authors: Kong
authors: Department of Cardiology, Yantaishan Hospital Yantai 264000, China.
authors: Wenbo
authors: W
authors: Liu
authors: Department of Medical Administration, Yantaishan Hospital Yantai 264000, China.
authors: Ge
authors: G
authors: Yan
authors: Department of Cardiology, Yantaishan Hospital Yantai 264000, China.
authors: Qiang
authors: Q
authors: Li
authors: Department of Emergency, Yantaishan Hospital Yantai 264000, China.
authors: Haiyan
authors: H
authors: Yang
authors: Department of Emergency, Yantaishan Hospital Yantai 264000, China.
authors: Fengxia
authors: F
authors: Yu
authors: Department of Cardiology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors: Haoming
authors: H
authors: Song
keywords: Poly-l-lactic acid; amorphous calcium phosphate; bioabsorbable stent; inflammation