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Lim K.S.,Korea Cardiovascular Stent Institute | Lim K.S.,Heart Health | Lim K.S.,Chonnam National University | Jeong M.H.,Korea Cardiovascular Stent Institute | And 20 more authors.
Korean Circulation Journal | Year: 2013

Background and Objectives: The aim of this study was to examine the histolopathogical effects among the biolimus, zotarolimus, and everolimus eluting stent (EES) in the porcine coronary restenosis model. Subjects and Methods: Pigs were randomized into three groups in which the coronary arteries (15 pigs, 10 coronaries in each group) had either a biolimus A9 eluting stent (BES, n=10), zotarolimus eluting stent (ZES, n=10) or an EES (n=10). Histopathologic analysis was performed at 28 days after stenting. Results: There were no significant differences in the injury score among the three groups. There was a significant difference in the internal elastic lamina, lumen area, neointima area, percent area stenosis, and the fibrin and inflammation score among the three groups (4.3±0.53 mm2, 2.5±0.93 mm 2, 1.8±1.03 mm2, 40.7±20.80%, 1.7±0.41, 1.4±0.72 in the BES group vs. 5.1±0.55 mm 2, 2.3±1.14 mm2, 2.8±1.00 mm2, 55.4±21.23%, 2.0±0.39, 1.6±0.76 in the ZES group vs. 4.4±0.53 mm2, 1.7±1.22 mm2, 2.8±1.23 mm2, 64.0±26.00%, 1.8±0.76, 2.1±0.90 in the EES group, respectively). BES is more effective in inhibiting neointimal hyperplasia compared to ZES and EES (p<0.0001). According to the fibrin and inflammation score, BES and EES are more effective in decreasing the fibrin deposition compared to ZES (p<0.001). Moreover, BES and ZES are more effective in reducing the inflammatory reaction compared to EES (p<0.001). Conclusion: The result demonstrates that BES shows better histopathological characteristics than ZES and EES at one month after stenting in the porcine coronary restenosis model. Copyright © 2013 The Korean Society of Cardiology.


Sim D.S.,Heart Health | Sim D.S.,Chonnam National University | Sim D.S.,Korea Cardiovascular Stent Institute | Jeong M.H.,Heart Health | And 28 more authors.
International Journal of Cardiology | Year: 2016

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 × 18 mm, n = 10), group 2 (BMSs with nitrogen-doped TiO2 film deposition, 3.0 × 18 mm, n = 10), group 3 [commercial everolimus-eluting stent, 3.0 × 18 mm, n = 10], and group 4 (polymer-free everolimus-eluting stent using nitrogen-doped TiO2 film deposition, 3.0 × 18 mm, 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. © 2016


Park D.S.,Korea Cardiovascular Stent Institute | Park D.S.,Chonnam National University | Park J.-K.,CGBio Co. | Jeong M.H.,Korea Cardiovascular Stent Institute | And 21 more authors.
Macromolecular Research | Year: 2015

Drug-eluting stents, which are widely used in percutaneous coronary intervention, are fabricated with various considerations, such as drugs, design, polymers, and coating techniques. The aim of this study was to compare tacrolimus-eluting stents (TES), sirolimus-eluting stents (SES) and everolimus-eluting stents (EES) under identical conditions. Poly(lactic-co-glycolic acid) (PLGA) biodegradable polymer was used to coat bare metal stents (Chonnam National University Hospital Stent, CNUH Stent) with the drugs in all fabricating procedures with an ultrasonic stent-coating machine. Surface morphologies of the stents were investigated by scanning electron microscopy. The effect of drugs released from stents on rat smooth muscle and human umbilical vein endothelial cells was examined by MTT assay. The stents were implanted in rabbit iliac arteries randomly, with either TES (n=10), SES (n=10), or EES (n=10). After six weeks of implantation, the stents were isolated and subjected to histopathological analysis. Cell viability decreased in a dose-dependent manner. The surface morphologies of the stents showed a smooth and uniform shape. The release patterns of the stents showed similar profiles over 30 days. There were no significant differences in the injury score, internal elastic lamina, lumenal area, neointimal area, percent area stenosis, and inflammation score among the three groups. However, there was a significant difference in the fibrin score (0.6±0.44 in the TES, vs. 0.8±0.48 in the SES, vs. 0.8±0.61 in the EES, n=10, p<0.05). This study showed that tacrolimus was not inferior to sirolimus (SRL) and everolimus (EVL). Moreover, tacrolimus (TCL) is more effective in decreasing the fibrin score. Therefore, tacrolimus can be a useful alternative drug for fabricating drug-eluting stents. [Figure not available: see fulltext.] © 2015, The Polymer Society of Korea and Springer Sciene+Business Media Dordrecht.


Kim N.Y.,Cardiovascular Convergence Research Center Nominated by Korea Ministry of Health and Welfare | Kim N.Y.,Chonnam National University | Lim K.S.,Korea Cardiovascular Stent Institute | Lim K.S.,Cardiovascular Convergence Research Center Nominated by Korea Ministry of Health and Welfare | And 42 more authors.
Journal of Materials Science: Materials in Medicine | Year: 2015

Chronic total occlusions (CTOs) are common in patients with peripheral arterial disease (PAD). This study aimed to examine the feasibility and reliability of a CTO induced by a thin biodegradable polymer (polyglycolic acid) coated copper stent in a porcine femoral artery. Novel thin biodegradable polymer coated copper stents (9 mm long) were crimped on an angioplasty balloon (4.5 mm diameter × 12 mm length) and inserted into the femoral artery. Histopathologic analysis was performed 35 days after stenting. In five of six stented femoral arteries, severe in-stent restenosis and total occlusion with collateral circulation were observed without adverse effects such as acute stent thrombosis, leg necrosis, or death at 5 weeks. Fibrous tissue deposition, small vascular channels, calcification, and inflammatory cells were observed in hematoxylin-eosin, Carstair’s, and von Kossa tissue stains; these characteristics were similar to pathological findings associated with CTOs in humans. The neointima volume measured by micro-computed tomography was 93.9 ± 4.04 % in the stented femoral arteries. CTOs were reliably induced by novel thin biodegradable polymer coated copper stents in porcine femoral arteries. Successful induction of CTOs may provide a practical understanding of their formation and application of an interventional device for CTO treatment. © 2015, Springer Science+Business Media New York.


Lim K.S.,Korea Cardiovascular Stent Institute | Lim K.S.,Cardiovascular Convergence Research Center Nominated by Korea Ministry of Health and Welfare | Lim K.S.,Chonnam National University | Park J.-K.,Sunchon National University | And 30 more authors.
Journal of Materials Science: Materials in Medicine | Year: 2016

The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-l-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78 % in BMS vs. 51.5 ± 12.20 % in AES vs. 34.7 ± 7.23 % in SES vs. 28.7 ± 7.30 % in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0–1.0) in BMS vs. 1.0 (range 1.0–1.0) in AES vs. 2.0 (range 2.0–2.0) in SES vs. 2.0 (range 2.0–2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88 % in BMS vs. 50.4 ± 14.87 % in AES vs. 34.5 ± 7.22 % in SES vs. 28.9 ± 7.22 % in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia. © 2016, Springer Science+Business Media New York.


Lim K.S.,Korea Cardiovascular Stent Institute | Lim K.S.,Chonnam National University | Jeong M.H.,Korea Cardiovascular Stent Institute | Jeong M.H.,Chonnam National University | And 17 more authors.
Journal of Cardiology | Year: 2014

Background: Polymer-free drug-eluting stents (DES) may overcome the shortcomings of polymer-based DES. The aim of this study was to examine the effect of the polymer-free TiO2 film-coated stent with abciximab or alpha lipoic acid in a porcine coronary overstretch restenosis model. Methods: Pigs were randomized into four groups in which the coronary arteries (24 pigs, 48 coronaries in each group) had TiO2 film-coated stent with abciximab (TCA, n=12), TiO2 film-coated stent with alpha lipoic acid (TCALA, n=12), biolimus A9-eluting stents with biodegradable polymer (BES, n=12), and TiO2 film-coated stent (TCstent, n=12). Histopathologic analysis was performed at 28 days after stenting. Results: There was no significant difference in the injury score and internal elastic lamina (IEL) among the four groups. There were significant differences in the lumen area, neointima area, percent area stenosis, fibrin score, and inflammation score among the four groups [2.7±1.0mm2, 2.6±0.94mm2, 48.9±16.25%, 1.0 (range 0.0-3.0), 1.0 (range 0.0-2.0) in TCA stent group vs. 2.7±1.24mm2, 2.9±0.83mm2, 53.5±17.19%, 1.0 (range 0.0-2.0), 1.0 (range 0.0-2.0) in TCALA stent group vs. 2.7±1.30mm2, 2.6±1.06mm2, 50.1±23.20%, 2.0 (range 1.0-3.0), 2.0 (range 1.0-3.0) in BES group vs. 1.7±0.63mm2, 3.3±0.58mm2, 60.2±10.12%, 0.5 (range 0.0-2.0), 1.0 (range 0.0-2.0) in TC stent group, respectively]. Conclusion: TCA and TCALA are more effective to reduce neointimal hyperplasia compared to TC. Moreover, fibrin and inflammation scores are significantly lower in TCA and TCALA than BES in porcine coronary restenosis model. © 2014 .

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