Sun-Jung Song

Adsorption of pyridine onto the metal organic framework MIL-101

The adsorption of pyridine onto the metal organic framework MIL-101 was investigated by experimental and theoretical methods. The amount of pyridine adsorbed on MIL-101 was extraordinarily large at 20 °C, corresponding to about 950 mg/g of dried MIL-101 and approximately half of the voids being filled. Most of the pyridine that had filled the voids was rapidly removed by evacuation at room temperature, but some of the pyridine was so strongly adsorbed that it was retained even under evacuation at 150 °C. Although IR spectra of the adsorbed pyridine indicated the adsorption of pyridine as pyridinium ions and coordinated pyridine at low temperatures, increasing the adsorption temperature induced partial cleavage of the pyridine rings. The high stabilization energy of pyridine on the coordinative unsaturated sites (CUS) of MIL-101, obtained by theoretical calculation, -103 kJ/mol, supported the strong adsorption of pyridine on the CUS.

Effect of polymer-free TiO2 stent coated with abciximab or alpha lipoic acid in porcine coronary restenosis model.

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 ± 1.0mm(2), 2.6 ± 0.94 mm(2), 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 ± 1.24 mm(2), 2.9 ± 0.83 mm(2), 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 ± 1.30 mm(2), 2.6 ± 1.06 mm(2), 50.1 ± 23.20%, 2.0 (range 1.0-3.0), 2.0 (range 1.0-3.0) in BES group vs. 1.7 ± 0.63 mm(2), 3.3 ± 0.58 mm(2), 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.

Novel abciximab-Kruppel-like factor 4-plasmid dual-delivery titanium dioxide-coated coronary stent

a Department of Cardiology, Chonnam National University Hospital, Gwangju, Republic of Korea b Heart Research Center, Chonnam National University Hospital, Gwangju, Republic of Korea c Department of Molecular Medicine and Advanced Chemical & Engineering, Chonnam National University Graduate School, Gwangju, Republic of Korea d Center for Functional Nano Fine Chemicals & School of Applied Chemical Engineering, Chonnam National University, Gwangju, Republic of Korea e Institute of Interventional Medicine, M.I. Tech Co., Ltd., Pyeongtaek, Republic of Korea

Development of Blood Compatible Alpha-lipoic acid Coated Stent with a Good Adhesive by Low Temperature Plasma Polymerization

Neointimal hyperplasia is a main cause for in-stent restenosis after stent-implantation and is triggered by inflammatory response to foreign materials. It can be inhibited if the stent is modified to have good blood compatibility by coating drug compounds. Low temperature plasma polymerization of 1, 2-diaminocyclohexane was performed to prepare more adhesive polymeric thin film onto the metallic stent. Then, the chemical grafting of α-lipoic acid (ALA) was carried out to improve blood compatibility of stent. Drugs containing carboxylic groups can be chemically grafted through the formation of amide bond in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide methiodide onto the DACH deposited stent surface. ALA grafted film showed good mechanical stability and blood compatibility.