Duration of dual antiplatelet therapy following percutaneous coronary intervention with drug-eluting stents: a review of recent evidence

Curcumin accelerates reendothelialization and ameliorates intimal hyperplasia in balloon-injured rat carotid artery via the upregulation of endothelial cell autophagy

Delayed reendothelialization and intimal hyperplasia (IH) contribute to the failure of vascular interventions. Curcumin (Cur) has been used for various types of diseases with antioxidant, antiproliferative and anti-inflammatory effects. However, investigations involving the application of Cur in inhibiting IH are limited. The aim of the present study was to evaluate the potential therapeutic effects of Cur and its underlying mechanisms on a rat model of carotid artery (CA) intimal injury. In vitro, an endothelial cell (EC) migration assay was conducted using cultured primary human umbilical vein endothelial cells (HUVECs) that were exposed to Cur. In vivo, CA angioplasty injury was used to generate a rat model of intimal injury. CAs were collected at 3 days, and 1 and 4 weeks after injury, respectively, for western blot analysis and double-immunofluorescence analyses, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining, oxidative stress indicator analysis and hematoxylin and eosin staining of the neointima. In vivo, Cur significantly enhanced the migration and healing of HUVECs and simultaneously promoted microtubule-associated protein light chain 3-II (LC3-II) expression when HUVECs were subjected to an artificial scratch. In vitro, endangium from the Cur-treated rats exhibited a significantly reduced number of apoptotic ECs and oxidative stress level compared to that of the sham group. In addition, Cur treatment markedly improved quantification of the LC3-II concomitant with the downregulation of p62 in the injured CA. At 1 week following injury, sizable neointimal lesions had developed, although prominent intima thickening was not observed. At 4 weeks, apparent hemadostenosis occurred resulting from the exorbitance IH. Cur treatment markedly reduced the thickness of the neointimal lesion. It is noteworthy that high-dose Cur may have exerted more significant effects than low-dose Cur. Cur can potentially become a therapeutic drug for angiostenosis by imparting a protective effect that accelerates reendothelialization and ameliorates IH and was mediated by its pro-autophagic effect.

Safety and effectiveness of the Genous™ endothelial progenitor cell-capture stent in the first year following ST-elevation acute myocardial infarction: A single center experience and review of the literature

PURPOSE

The Genous™ stent (GS) is designed to accelerate endothelization, which is potentially useful in the pro-thrombotic environment of ST-elevation acute myocardial infarction (STEMI). We aimed to evaluate the safety and effectiveness of the GS in the first year following primary percutaneous coronary intervention (PCI) and to compare our results with the few previously published studies.

METHODS AND MATERIALS

All patients admitted to a single center due to STEMI that underwent primary PCI using exclusively GS, between May 2006 and January 2012, were enrolled. The primary study endpoints were major adverse cardiac events (MACEs), defined as the composite of cardiac death, acute myocardial infarction and target vessel revascularization, at one and 12 months.

RESULTS

In the cohort of 109 patients (73.4% male, 59 ± 12 years), 24.8% were diabetic. PCI was performed in 116 lesions with angiographic success in 99.1%, using 148 GS with median diameter of 3.00 mm (2.50-4.00) and median length of 15 mm (9-33). Cumulative MACEs were 2.8% at one month and 6.4% at 12 months. Three stent thromboses (2.8%), all subacute, and one stent restenosis (0.9%) occurred. These accounted for the four target vessel revascularizations (3.7%). At 12 months, 33.9% of patients were not on dual antiplatelet therapy.

CONCLUSIONS

GS was safe and effective in the first year following primary PCI in STEMI, with an apparently safer profile comparing with the previously published data.

SUMMARY

We report the safety and effectiveness of the Genous™ stent (GS) in the first year following primary percutaneous coronary intervention in ST-elevation acute myocardial infarction. A comprehensive review of the few studies that have been published on this subject was included and some suggest a less safe profile of the GS. Our results and the critical review included may add information and reinforce the safety and effectiveness of the GS in ST-elevation in acute myocardial infarction.

Toll-like receptor 2/6 agonist macrophage-activating lipopeptide-2 promotes reendothelialization and inhibits neointima formation after vascular injury

OBJECTIVE

Reendothelialization after vascular injury (ie, balloon angioplasty or stent implantation) is clinically extremely relevant to promote vascular healing. We here investigated the therapeutic potential of the toll-like receptor 2/6 agonist macrophage-activating lipopeptide (MALP)-2 on reendothelialization and neointima formation in a murine model of vascular injury.

APPROACH AND RESULTS

The left common carotid artery was electrically injured, and reendothelialization was quantified by Evans blue staining after 3 days. A single injection of MALP-2 (1 or 10 µg, IV) after vascular injury accelerated reendothelialization (P<0.001). Proliferation of endothelial cells at the wound margins determined by 5-ethynyl-2'-deoxyuridine incorporation was significantly higher in MALP-2-treated animals (P<0.05). Furthermore, wire injury-induced neointima formation of the left common carotid artery was completely prevented by a single injection of MALP-2 (10 µg, IV). In vitro, MALP-2 induced proliferation (BrdU incorporation) and closure of an artificial wound of endothelial cells (P<0.05) but not of smooth muscle cells. Protein array and ELISA analysis of isolated primary endothelial cells and ex vivo stimulated carotid segments revealed that MALP-2 stimulated the release of multiple growth factors and cytokines predominantly from endothelial cells. MALP-2 induced a strong activation of the mitogen-activated protein kinase cascade in endothelial cells, which was attenuated in smooth muscle cells. Furthermore, MALP-2 significantly enhanced circulating monocytes and hematopoietic progenitor cells.

CONCLUSIONS

The toll-like receptor 2/6 agonist MALP-2 promotes reendothelialization and inhibits neointima formation after experimental vascular injury via enhanced proliferation and migration of endothelial cells. Thus, MALP-2 represents a novel therapeutic option to accelerate reendothelialization after vascular injury.

Microelectromechanical systems and nanotechnology: a platform for the next stent technological era

Nanotechnology is the design and development of materials, structures, and devices with at least 1 dimension between the 1- and 100-nm-size scale. Manipulating matter at the atomic scale offers unique opportunities in material design particularly in biological interfaces. In this short review, we explore the disruptive technological opportunities that nanotechnology and microelectromechanical systems may offer in possible future stent designs along with safety issues that may surface with the use of nanoparticles in medical devices.

Synthesis of biomimetic segmented polyurethanes as antifouling biomaterials

Controlling the non-specific adsorption of proteins, cells and bacteria onto biomaterial surfaces is of crucial importance for the development of medical devices with specific levels of performance. Among the strategies pursued to control the interactions between material surfaces and biological tissues, the immobilization of non-fouling polymers on biomaterial surfaces as well as the synthesis of the so-called biomimetic polymers are considered promising approaches to elicit specific cellular responses. In this study, in order to obtain materials able to prevent infectious and thrombotic complications related to the use of blood-contacting medical devices, heparin-mimetic segmented polyurethanes were synthesized and fully characterized. Specifically, sulfate or sulfamate groups, known to be responsible for the biological activity of heparin, were introduced into the side chain of a carboxylated polyurethane. Due to the introduction of these groups, the obtained polymers possessed a higher hard/soft phase segregation (lower glass transition temperatures) and a greater hydrophilicity than the pristine polymer. In addition, the synthesized polymers were able to significantly delay the activated partial thromboplastin time, this increased hemocompatibility being related both to polymer hydrophilicity and to the presence of the -SO3H groups. This last feature was also responsible for the ability of these biomimetic polymers to prevent the adhesion of a strain of Staphylococcus epidermidis.