The purpose of this study was to develop a novel polymer cuff for the local delivery of alpha-lipoic acid (ALA) to inhibit neointimal formation in vivo. The polymer cuff was fabricated by incorporating the ALA into poly-(D,L-lactide-co-caprolactone) 40:60 (PLC), with or without methoxy polyethylene glycol (MethoxyPEG). The release kinetics of ALA and in vitro degradation by hydrolysis were analyzed by HPLC and field emission scanning electron microscopy (FE-SEM), respectively. In vivo evaluation of the effect of the ALA-containing polymer cuff was carried out using a rat femoral artery cuff injury model. At 24 h, 48% or 87% of the ALA was released from PCL cuffs with or without MethoxyPEG. FE-SEM results indicated that ALA was blended homogenously in the PLC with MethoxyPEG, whereas ALA was distributed on the surface of the PLC cuff without MethoxyPEG. The PLC cuff with MethoxyPEG showed prolonged and controlled release of ALA in PBS, in contrast to the PLC cuff without MethoxyPEG. Both ALA-containing polymer cuffs had a significant effect on the inhibition of neointimal formation in rat femoral artery. Novel ALA-containing polymer cuffs made of PLC were found to be biocompatible and effective in inhibiting neointimal formation in vivo. Polymer cuffs containing MethoxyPEG allowed the release of ALA for one additional week, and the rate of drug release from the PLC could be controlled by changing the composition of the polymer. These findings demonstrate that polymer cuffs may be an easy tool for the evaluation of anti-restenotic agents in animal models.
Animals ; Coronary Restenosis/*therapy ; Delayed-Action Preparations ; Male ; Materials Testing ; Polyesters/*administration & dosage/*chemical synthesis ; Polyethylene Glycols/chemical synthesis ; Rats ; Rats, Sprague-Dawley ; Surface Properties

PURPOSE: Thiazolidinediones are insulin-sensitizing agents that reduce neointimal proliferation and the adverse clinical outcomes associated with percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM). There is little data on whether or not low dose pioglitazone reduces adverse clinical outcomes. MATERIALS AND METHODS: The study population included 121 DM patients with coronary artery disease and they were randomly assigned to 60 patients taking 15 mg of pioglitazone daily in addition to their diabetic medications and 61 patients with placebo after the index procedure with drug-eluting stents (DESs). The primary end points were rate of in-stent restenosis (ISR) and change in atheroma volume and in-stent neointimal volume. The secondary end points were all-cause death, myocardial infarction (MI), stent thrombosis and re-PCI. RESULTS: There were no statistical differences in the clinical outcomes and the rate of ISR between the two groups [all-cause death; n=0 (0%) in the pioglitazone group vs. n=1 (1.6%) in the control group, p=0.504, MI; n=2 (3.3%) vs. n=1 (1.6%), p=0.465, re-PCI; n=6 (10.0%) vs. n=6 (9.8%), p=0.652, ISR; n=4 (9.3%) vs. n=4 (7.5%), p=1.000, respectively]. There were no differences in changes in neointimal volume, percent neointimal volume, total plaque volume and percent plaque volume between the two groups on intravascular ultrasonography (IVUS) study. CONCLUSION: Our study demonstrated that low dose pioglitazone does not reduce rate of ISR, neointimal volume nor atheroma volume in DM patients who have undergone PCI with DESs, despite the limitations of the study.
Aged ; Coronary Artery Disease/drug therapy/radiography/*therapy ; Coronary Restenosis/*prevention & control ; *Drug-Eluting Stents ; Female ; Humans ; Hypoglycemic Agents/therapeutic use ; Male ; Middle Aged ; Thiazolidinediones/administration & dosage/*therapeutic use

The formation of advanced glycation end products (AGEs), in various tissues has been known to enhance immunoinflammatory reactions and local oxidant stresses in long standing diabetes. Recently, AGEs have been reported to play a role in neointimal formation in animal models of arterial injury. We attempted to determine whether the serum levels of AGEs are associated with coronary restenosis in diabetic patients. Blood samples were collected from diabetic patients with coronary artery disease undergoing stent implantation and the serum levels of AGEs were analyzed by the fluorescent intensity method. The development of in-stent restenosis (ISR) was evaluated by a 6-month follow-up coronary angiography. A total of 263 target lesions were evaluated, in 203 patients. The ISR rate in the high-AGE (> 170 U/ml) group (40.1%) was significantly higher than in the low-AGE group (< or =170 U/ml) (19.6%) (p < 0.001). Furthermore, multivariate analysis revealed that a high level of serum AGEs is an independent risk factor for the development of ISR (odds ratio, 2.659; 95% CI, 1.431-4.940; p=0.002). The serum levels of AGEs constitute an excellent predictive factor for ISR, and should be one of the guidelines for medical therapy and interventional strategy to prevent ISR in diabetic patients.
Aged ; Coronary Arteriosclerosis/epidemiology/*metabolism/*therapy ; Coronary Restenosis/epidemiology/*metabolism ; Diabetes Mellitus, Type 2/epidemiology/*metabolism ; Female ; Glycosylation End Products, Advanced/*blood ; Humans ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't ; Risk Factors ; *Stents

BACKGROUND: The heme oxygenase-1 gene (HMOX1) promoter polymorphisms modulate its transcription in response to oxidative stress. This study screened for HMOX1 polymorphisms and investigated the association between HMOX1 polymorphisms and coronary artery disease (CAD) in the Korean population. METHODS: The study population consisted of patients with CAD with obstructive lesions (n=110), CAD with minimal or no lesions (n=40), and controls (n=107). Thirty-nine patients with CAD with obstructive lesions underwent follow-up coronary angiography after six months for the presence of restenosis. The 5'-flanking region containing (GT)n repeats of the HMOX1 gene was analyzed by PCR. RESULTS: The numbers of (GT)n repeats in the HMOX1 promoter showed a bimodal distribution. The alleles were divided into two subclasses, S25 and L25, depending on whether there were less than or equal to and more than 25 (GT)n repeats, respectively. The allele and genotype frequencies among groups were statistically not different. More subjects in the S25-carrier group had the low risk levels of high sensitivity C-reactive protein (hsCRP) for the CAD than those in the non-S25 carrier group (P=0.034). Multivariate logistic regression analysis revealed that the genotypes of (GT)n repeats were not related to CAD status. The restenosis group in the coronary angiography follow-up did not show any significant difference in HMOX1 genotype frequency. CONCLUSIONS: The HMOX1 genotypes were not found to be associated with CAD, but the short allele carrier group contained more individuals with hsCRP values reflecting low risk of cardiovascular disease in the Korean population.
5' Untranslated Regions ; Adult ; Alleles ; Asian Continental Ancestry Group/*genetics ; C-Reactive Protein/analysis ; Coronary Angiography ; Coronary Artery Disease/*genetics/pathology ; Coronary Restenosis/complications/therapy ; Dinucleotide Repeats/genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Heme Oxygenase-1/*genetics ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Promoter Regions, Genetic ; Republic of Korea ; Risk Factors