A coated implantable medical device 10 includes a structure 12 adapted for introduction into the vascular system, esophagus, trachea, colon, biliary tract, or urinary tract; at least one layer 18 of a bioactive material positioned over the structure 12; and at least one porous layer 20 positioned over the bioactive material layer 18. Preferably, the structure 12 is a coronary stent, and the bioactive material is at least one of heparin, dexamethasone or a dexamethasone derivative. The device 10 includes layers 18 and 22 of heparin and dexamethasone, the layer 22 of dexamethasone being positioned above the layer 18 of heparin. The layers of bioactive material also can be individual materials or a combination of different materials. Unexpectedly, the more soluble heparin markedly promotes the release of the less soluble dexamethasone above it. The porous layer 20 is composed of a polymer applied by vapor or plasma deposition and provides a controlled release of the bioactive material. It is particularly preferred that the polymer is a polyimide, parylene or a parylene derivative, which is deposited without solvents, heat or catalysts, merely by condensation of a monomer vapor.

Coated implantable medical device

Background: A substantial proportion of patients receiving fibrinolytic therapy for myocardial infarction with ST-segment elevation have inadequate reperfusion or reocclusion of the infarct-related artery, leading to an increased risk of complications and death. Methods: We enrolled 3491 patients, 18 to 75 years of age, who presented within 12 hours after the onset of an ST-elevation myocardial infarction and randomly assigned them to receive clopidogrel 8300-mg loading dose, followed by 75 mg once daily) or placebo. Patients received a fibrinolytic agent, aspirin, and when appropriate, heparin (dispensed according to body weight) and were echeduled to undergo angiography 48 to 192 hours after the start of study medication. The primary efficacy end point was a composite of an ocluded infarct-related artery (defined by a Thrombolysus in Myocardial Infarction flow grade of 0 or 1) on angiography or death or recurrent myocardial infarction before angiography. Results: The rates of the primary efficacy end point were 21.7 percent in the placebo group and 15.0 percent in the clopidogrel group, representing an absolute reduction of 6.7 percentage points in the rate and a 36 percent reduction in the odds of the end point with clopidogrel therapy (95 percent confidence interval, 24 to 47 percent; P<0.001). By 30 days, clopidogrel therapy reduced the odds ol the composite end point of death from cardiovascular causes, recurrent myocardial infarction, or recurrent ischemia leading to the need for urgent revascularization by 20 percent (from 14.1 to 11.6 percent, P=0.03). The rates of major bleeding and intracranial hemorrhage were similar in the two groups. Conclusions: In patients 75 years of age or younger who have myocardial infarction with ST-segment elevation and who receive aspirin and a standard fibrinolytic regimen, the addition of clopidogrel improves the patency rate of the infarct-related artery and reduces ischemic complications.

Addition of clopidogrel to aspirin and fibrinolytic therapy for myocardial infarction with ST-segment elevation

Recent experimental and human studies have shown that hyperuricemia is associated with hypertension, systemic inflammation, and cardiovascular disease mediated by endothelial dysfunction and pathologic vascular remodeling Elevated levels of C-reactive protein (CRP) have emerged as one of the most powerful independent predictors of cardiovascular disease In addition to being a marker of inflammation, recent evidence suggests that CRP may participate directly in the development of atherosclerotic vascular disease For investigating whether uric acid (UA)-induced inflammatory reaction and vascular remodeling is related to CRP, the UA-induced expression of CRP in human vascular smooth muscle cells (HVSMC) and human umbilical vein endothelial cells (HUVEC) was examined, as well as the pathogenetic role of CRP in vascular remodeling It is interesting that HVSMC and HUVEC expressed CRP mRNA and protein constitutively, revealing that vascular cells are another source of CRP production UA (6 to 12 mg/dl) upregulated CRP mRNA expression in HVSMC and HUVEC with a concomitant increase in CRP release into cell culture media Inhibition of p38 or extracellular signal-regulated kinase 44/42 significantly suppressed UA-induced CRP expression, implicating these pathways in the response to UA UA stimulated HVSMC proliferation whereas UA inhibited serum-induced proliferation of HUVEC assessed by 3H-thymidine uptake and cell counting, which was attenuated by co-incubation with probenecid, the organic anion transport inhibitor, suggesting that entry of UA into cells is responsible for CRP expression UA also increased HVSMC migration and inhibited HUVEC migration In HUVEC, UA reduced nitric oxide (NO) release Treatment of vascular cells with anti-CRP antibody revealed a reversal of the effect of UA on cell proliferation and migration in HVSMC and NO release in HUVEC, which suggests that CRP expression may be responsible for UA-induced vascular remodeling This is the first study to show that soluble UA, at physiologic concentrations, has profound effects on human vascular cells The observation that UA alters the proliferation/migration and NO release of human vascular cells, mediated by the expression of CRP, calls for careful reconsideration of the role of UA in hypertension and vascular disease

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Uric Acid–Induced C-Reactive Protein Expression: Implication on Cell Proliferation and Nitric Oxide Production of Human Vascular Cells

A prosthetic valve for implantation within a fluid conducting lumen within a body includes an elongate generally cylindrical radially collapsible valve body scaffold defining a fluid passageway therethrough for retentive positioning within the lumen. A radially collapsible leaf valve member is supported by the scaffold includes a number of valve leafs deflectable between a closed position restricting fluid flow through the passageway and an open position permitting fluid flow through the passageway. The leaf valve member includes an interior leaf valve frame defining a valve leaf aperture which is sealed by a fluid impermeable non-thrombogenic lining to prevent fluid flow therethrough.

Implantable prosthetic valve

This invention provides novel nanofiber enhanced surface area substrates and structures comprising such substrates for use in various medical devices, as well as methods and uses for such substrates and medical devices. In one particular embodiment, methods for enhancing cellular functions on a surface of a medical device implant are disclosed which generally comprise providing a medical device implant comprising a plurality of nanofibers (e.g., nanowires) thereon and exposing the medical device implant to cells such as osteoblasts.

Medical device applications of nanostructured surfaces

Background— Myocardial ischemia provides a potent stimulus to angiogenesis, and the mobilization and differentiation of endothelial progenitor cells (EPCs) has been shown to be important in this process. An elevated level of C-reactive protein (CRP) has emerged as one of the most powerful predictors of cardiovascular disease. However, the impact of CRP on EPC biology is unknown. Methods and Results— EPCs were isolated from the peripheral venous blood of healthy male volunteers. Cells were cultured in endothelial cell basal medium-2 in the absence and presence of CRP (5 to 20 μg/mL), rosiglitazone (1 μmol/L), and/or vascular endothelial growth factor. EPC differentiation, survival, and function were assayed. CRP at concentrations ≥15 μg/mL significantly reduced EPC cell number, inhibited the expression of the endothelial cell–specific markers Tie-2, EC-lectin, and VE-cadherin, significantly increased EPC apoptosis, and impaired EPC-induced angiogenesis. EPC-induced angiogenesis was dependent on the presenc...

C-Reactive Protein Attenuates Endothelial Progenitor Cell Survival, Differentiation, and Function Further Evidence of a Mechanistic Link Between C-Reactive Protein and Cardiovascular Disease

The invention relates to a method for healing blood vessels by stimulating the formation of a confluent endothelial autologous cell layer in vivo on an implantable metallic stent having a lumen and a luminal surface, and an exterior surface. More specifically, the method includes implanting the stent with a coating in a patient in need of thereof; wherein the coating includes one or more layers of a matrix covalently adherent on said luminal and exterior surface of said stent containing one or more pharmaceutical substances on said exterior surface and a therapeutically effective amount of a single type of antibody, antibody fragments or combinations thereof being compatible to binding selectively to a specific cell surface antigen of circulating autologous endothelial progenitor cells in peripheral blood. In addition, genetically engineered endothelial progenitor cells can be captured on said luminal surface of stent in vivo, to proliferate to form rapidly a confluent endothelium in situ.

Medical Device with Coating that Promotes Endothelial Cell Adherence

Compositions and methods are provided for producing a medical device such as a stent, a stent graft, a synthetic vascular graft, heart valves, coated with a biocompatible matrix which incorporates antibodies, antibody fragments, or small molecules, which recognize, bind to and/or interact with a progenitor cell surface antigen to immobilize the cells at the surface of the device. The coating on the device can also contain a compound or growth factor for promoting the progenitor endothelial cell to accelerate adherence, growth and differentiation of the bound cells into mature and functional endothelial cells on the surface of the device to prevent intimal hyperplasia. Methods for preparing such medical devices, compositions, and methods for treating a mammal with vascular disease such as restenosis, artherosclerosis or other types of vessel obstructions are disclosed.

Medical device with coating that promotes endothelial cell adherence and differentiation

Medical device with coating that promotes cell adherence and differentiation

Therapeutic and drug delivery systems are provided in the form of medical devices with coatings for capturing and immobilizing target cells such as circulating progenitor or genetically-altered mammalian cells in vivo. The genetically-altered cells are transfected with genetic material for expressing a marker gene and at least one therapeutic gene in a constitutively or controlled manner. The marker gene is a cell membrane antigen not found in circulating cells in the blood stream and therapeutic gene encodes a peptide for the treatment of disease, such as, vascular disease and cancer. The coating on the medical device may be a biocompatible matrix comprising at least one type of ligand, such as antibodies, antibody fragments, other peptides and small molecules, which recognize and bind the target cells. The therapeutic and/or drug delivery systems may be provided with a signal source such as activator molecules for stimulating the modified cells to express and secrete the desired marker and therapeutic gene products.

Michael Kutryk

Papers

C-Reactive Protein Attenuates Endothelial Progenitor Cell Survival, Differentiation, and Function Further Evidence of a Mechanistic Link Between C-Reactive Protein and Cardiovascular Disease

Medical Device with Coating that Promotes Endothelial Cell Adherence

Medical device with coating that promotes endothelial cell adherence and differentiation

Medical device with coating that promotes cell adherence and differentiation

Medical device with coating for capturing genetically-altered cells and methods of using same