title: A novel polymer-free drug-eluting stent coated with everolimus using nitrogen-doped titanium dioxide film deposition in a porcine coronary restenosis model.
abstract: BACKGROUND
  Titanium dioxide (TiO2) films have superior biocompatibility and may be effective as drug-binding matrices for drug-eluting stents (DESs). We sought to evaluate efficacy of a polymer-free DES coated with everolimus using nitrogen-doped TiO2 film deposition in a porcine coronary restenosis model.
  
  
  METHODS
  Forty coronary arteries in 20 pigs were randomly allocated to group 1 (bare-metal stents (BMSs), 3.0×18mm, n=10), group 2 (BMSs with nitrogen-doped TiO2 film deposition, 3.0×18mm, n=10), group 3 [commercial everolimus-eluting stent, 3.0×18mm, n=10], and group 4 (polymer-free everolimus-eluting stent using nitrogen-doped TiO2 film deposition, 3.0×18mm, n=10). Stents were randomly implanted in the left anterior descending coronary artery and left circumflex artery with stent:artery ratio of 1.3. Four weeks later, pigs underwent follow-up coronary angiography and were sacrificed for histopathologic analysis.
  
  
  RESULTS
  Percent area stenosis was greater in group 1 compared to groups 3 and 4 (46.4±13.8% vs. 30.2±11.7% vs. 29.2±8.9%, respectively, p=0.005). Fibrin score was lower in groups 1 and 2, compared to groups 3 and 4: 0.87±0.67 vs. 0.76±0.61 vs. 2.27±0.24 vs. 1.75±0.31, respectively, p<0.001). Injury score and inflammation score were not different. Comparison between DES showed a higher fibrin score in group 3 than group 4 (2.27±0.24 vs. 1.75±0.31, p=0.023).
  
  
  CONCLUSIONS
  In a porcine model of coronary restenosis, a novel polymer-free DES using nitrogen-doped TiO2 film deposition shows higher biocompatibility and compares favorably with a commercial DES.
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: Doo Sun
authors: DS
authors: Sim
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea. Electronic address: myungho@chollian.net.
authors: Myung Ho
authors: MH
authors: Jeong
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: Dae Sung
authors: DS
authors: Park
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: Jung Ha
authors: JH
authors: Kim
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: Kyung Seob
authors: KS
authors: Lim
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: In Ho
authors: IH
authors: Bae
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Piao
authors: P
authors: Zhehao
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Hae Young
authors: HY
authors: Yang
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Je Hoon
authors: JH
authors: Lee
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Dae Young
authors: DY
authors: Hyun
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Young Joon
authors: YJ
authors: Hong
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea; Korea Cardiovascular Stent Institute, Jangseong, Republic of Korea.
authors: Ju Han
authors: JH
authors: Kim
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Youngkeun
authors: Y
authors: Ahn
authors: Heart Research Center Nominated by Korea Ministry of Health and Welfare, Gwangju, Republic of Korea; Cardiovascular Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea.
authors: Jung Chaee
authors: JC
authors: Kang
mesh_terms: D000818:Animals; D023903:Coronary Restenosis / Q000473:pathology / Q000628:therapy*; D004195:Disease Models, Animal; D054855:Drug-Eluting Stents / Q000639:trends*; D000068338:Everolimus / Q000008:administration & dosage*; D009584:Nitrogen / Q000008:administration & dosage*; D011108:Polymers; D011474:Prosthesis Design; D011897:Random Allocation; D013552:Swine; D014025:Titanium / Q000008:administration & dosage*
chemical_list: D011108:Polymers; C009495:titanium dioxide; D000068338:Everolimus; D014025:Titanium; D009584:Nitrogen
keywords: Drug-eluting stents; Polymers; Titanium dioxide