79 results about "Thrombogenicity" patented technology

An improved prosthetic mitral valve is provided having advantageous hemodynamic performance, nonthrombogenicity, and durability. The valve includes a valve body having an inflow annulus and an outflow annulus. Commissural attachment locations are disposed adjacent the outflow annulus. An anterior leaflet and a posterior leaflet of the valve are shaped differently from one another. The inflow annulus preferably is scalloped so as to have a saddle-shaped periphery having a pair of relatively high portions separated by a pair of relatively low portions. The anterior high portion preferably is vertically higher than the posterior high portion.

The present invention relates to improved methods for making and using bioadhesive, bioresorbable, anti-adhesion compositions made of intermacromolecular complexes of carboxyl-containing polysaccharides, polyethers, polyacids, polyalkylene oxides, multivalent cations and/or polycations. The polymers are associated with each other, and are then either dried into membranes or sponges, or are used as fluids or microspheres. Bioresorbable, bioadhesive, anti-adhesion compositions are useful in surgery to prevent the formation and reformation of post-surgical adhesions. The compositions are designed to breakdown in-vivo, and thus be removed from the body. Membranes are inserted during surgery either dry or optionally after conditioning in aqueous solutions. The anti-adhesion, bioadhesive, bioresorptive, antithrombogenic and physical properties of such membranes and gels can be varied as needed by carefully adjusting the pH and/or cation content of the polymer casting solutions, polyacid composition, the polyalkylene oxide composition, or by conditioning the membranes prior to surgical use. Multi-layered membranes can be made and used to provide further control over the physical and biological properties of antiadhesion membranes. Membranes and gels can be used concurrently. Antiadhesion compositions may also be used to lubricate tissues and/or medical instruments, and/or deliver drugs to the surgical site and release them locally.

An intraluminal device implantable in a body lumen having an atheroma therein in the vicinity of a side-branch vessel includes a mesh-like tube of bio-compatible material formed with liquid-permeable window openings. The mesh-like tube has an expanded condition in which the tube diameter is slightly larger than the diameter of the body lumen in which it is to be implanted, and the tube length is sufficient to cover the atheroma and the side-branch orifice, and to be anchored to the body lumen around the periphery of the atheroma, and a contracted condition wherein it is sufficiently flexible so as to be easily manipulatable through the body lumen to the site of the atheroma. The mesh-like tube, in its expanded condition, has window openings of a size and distribution such as to structurally stabilize the atheroma and to keep embolic material originating from the atheroma in place on the wall of the body lumen, while diverting embolic material of predetermined size present in the blood flowing through the mesh-like tube from the side-branch orifice, without substantially impeding the blood flow, or increasing the thrombogenitic properties, of the blood flowing into the side-branch orifice.

Endothelialization of a bodily fluid or tissue-contacting, particularly blood-contacting, surface may be accomplished to render that surface substantially non-thrombogenic. Thrombosis may also be mitigated or eliminated by providing an eroding layer on the surface that results in the removal of any thrombus formation as the layer erodes. An implantable device may utilize at least one surface having a plurality of nano-craters thereon that enhance or promote endothelialization. Additionally, an implantable device may have at least one first degradable layer for contacting bodily fluid or tissue and disposed about a central core, and at least one second degradable layer between the first degradable layer and the central core. The first degradable layer has a first degradation rate and the second degradable layer has a second degradation rate which degrades more slowly than the first degradable layer on contact with bodily fluid or tissue.

PCT No. PCT/GB97/01173 Sec. 371 Date Apr. 30, 1999 Sec. 102(e) Date Apr. 30, 1999 PCT Filed Apr. 30, 1997 PCT Pub. No. WO97/41164 PCT Pub. Date Nov. 6, 1997Polymers having non-thrombogenic properties can be prepared by copolymerizing monomers of at least three classes selected from (a) monomers having sulphate groups, (b) monomers having sulphonate groups, (c) monomers having sulphamate groups, (d) monomers having polyoxyalkylene ether groups, and (e) monomers having zwitterionic groups. The polymers can additionally be provided with anti-thrombogenic properties by including an additional comonomer having a pendant heparin (or hirudin, warfarin or hyaluronic acid) group. The polymers can be used as coating materials for medical devices, such as tubing or connectors, in order to provide them with non-thrombogenic, and optionally anti-thrombogenic, properties.

A new embolic agent, bioabsorbable polymeric material (BPM) is incorporated to a Guglielmi detachable coil (GDC) to improve long-term anatomic results in the endovascular treatment of intracranial aneurysms. The embolic agent, comprised at least in part of at least one biocompatible and bioabsorbable polymer and growth factors, is carried by hybrid bioactive coils and is used to accelerate histopathologic transformation of unorganized clot into fibrous connective tissue in experimental aneurysms. An endovascular cellular manipulation and inflammatory response are elicited from implantation in a vascular compartment or any intraluminal location. Thrombogenicity of the biocompatible and bioabsorbable polymer is controlled by the composition of the polymer. The coil further is comprised at least in part of a growth factor or more particularly a vascular endothelial growth factor, a basic fibroblast growth factor or other growth factors. The biocompatible and bioabsorbable polymer is in the illustrated embodiment at least one polymer selected from the group consisting of polyglycolic acid, poly~glycolic acid/poly-L-lactic acid copolymers, polycaprolactive, polyhydroxybutyrate/hydroxyvalerate copolymers, poly-L-lactide. Polydioxanone, polycarbonates, and polyanhydrides.

A coating and method for a coating an implantable device or prostheses are disclosed. The coating includes an undercoat of polymeric material containing an amount of biologically active material, particularly heparin, dispersed herein. The coating further includes a topcoat which covers less than the entire surface of the undercoat and wherein the topcoat comprises a polymeric material substantially free of pores and porosigens. The polymeric material of the topcoat can be a biostable, biocompatible material which provides long term non-thrombogenicity to the device portion during and after release of the biologically active material.

Polymer surface modification method comprising the steps of first forming a surface of primary reactive end groups tethered to the polymer chain ends during fabrication of an article, and then modifying the reactive surface with bio-active molecules, hydrophilic and hydrophobic monomers, oligomers, or polymers to attain specific surface properties. Alternatively, a multifunctional coupling agent can be used to couple the primary reactive group to a second reactive group capable of reacting with a functional group associated with bio-active molecules, hydrophilic and hydrophobic monomers, oligomers, and polymers to attain specific surface properties. The invention involves bringing reactive endgroups to the surface with surface active spacer attached to the polymer chain end. The surface active spacer allows the migration and enrichment of reactive end groups to the surface during fabrication. The invention provides medical devices having a bio-interface with anti-thrombogenic properties, lubricity, selective adsorption, and antimicrobial properties.

The present invention relates generally to a diagnostic device including a prognostic assay for parameters which are indicative of a condition or event associated with the systemic vasculature. More particularly, the present invention provides an assay to detect parameters associated with a vascular disease including cardiovascular, stroke, pulmonary, renovascular, cerebrovascular, thrombotic or generalized arterial or venous condition or event including acute coronary syndrome such as but not limited to acute myocardial infarction, heart failure, atheromoma or a thrombotic condition. The identification of these parameters or more particularly a pattern of parameters enables the diagnosis of a condition or event or the determination of the risk of development of a condition or event associated to the systemic vasculature. Still more particularly, the present invention is directed to a diagnostic device comprising a set of members wherein one or more of said members has or have specific or generic binding partners in a biological sample from an animal including human subject wherein the pattern of binding of the members to the binding partners is indicative, predictive or otherwise associated with a likelihood of a condition or event within the systemic vasculature. The absence of detection of specific or generic binding partners is also of indicative or predictive value. This is particularly important in cases where patients are unable to communicate advice to a physician on their own condition, such as during surgery or for patients in a coma. It is also useful in determining the risk of a vascular disease including cardiovascular, stroke, pulmonary, renovascular, cerebrovascular, thrombotic or generalized arterial or venous conditions or events in a healthy subject or a subject entering into an exposure to risk such as surgery or chemotherapy. The present invention is useful inter alia for the identification and/or quantitation of biochemical markers of conditions or events in the systemic vasculature such as heart disease, heart disorders, infections of the heart, stroke and thrombosis as well as the determination of a risk of development of these conditions including the absence of disorders or absence of risk of the development of a disorder. The assessment of such conditions may be made in a clinical setting, as part of triage, as part of a routine testing protocol and/or as a laboratory procedure.

Disclosed herein are methods for modifying a substrate having a hydrophobic surface. Also disclosed are modified hydrophobic substrates. The modified hydrophobic substrates and methods disclosed herein advantageously improve cell affinity and antithrombogenicity of hydrophobic surfaces.

Polymers having non-thrombogenic properties can be prepared by copolymerizing monomers of at least three classes selected from (a) monomers having sulphate groups, (b) monomers having sulphonate groups, (c) monomers having sulphamate groups, (d) monomers having polyoxyalkylene ether groups, and (e) monomers having zwitterionic groups. The polymers can additionally be provided with anti-thrombogenic properties by including an additional comonomer having a pendant heparin (or hirudin, warfarin or hyaluronic acid) group. The polymers can be used as coating materials for medical devices, such as tubing or connectors, in order to provide them with non-thrombogenic, and optionally anti-thrombogenic, properties.

Composition consisting of heparin fractions having reproducible characteristics with average molecular weight of 5,200 D obtained by depolymerization with gamma radiation and subsequent fractionation by gel permeation, having high antithrombotic properties and particularly suitable for the prophilaxis and the therapy of the alterations of the plasmatic homeostasis.

Comblike, surfactant polymers for changing the surface properties of biomaterials are provided. Such surfactant polymers comprise a polymeric backbone of repeating monomeric units having functional groups for coupling with side chains, a plurality of hydrophobic side chains linked to the backbone via the functional groups, and a plurality of hydrophilic side chains linked to said backbone via the functional groups. Medical devices coated with the surfactant polymers are also provided. The surfactant polymers may be used to decrease the thrombogenic properties, encapsulation, and bacterial colonization of medical devices.

New ampholyte biomaterial compounds containing ampholyte moieties are synthesized and integrated into polymeric assemblies to provide hydrophilic polymers exhibiting improved biocompatibility, haemocompatibility, hydrophilicity non-thrombogenicity, anti-bacterial ability, and mechanical strength, as well as suitability as a drug delivery platform.

The object of the present invention is achieved by providing a copolymer, in particular, a block copolymer which has excellent coating formation ability, adhesive properties to a substrate, and does not adsorb protein; an antithrombotic coating agent which has superior antithrombotic properties and adhesive properties to a substrate to those of the conventional antithrombotic coating agent; and a medical instrument which is obtained by coating the antithrombotic coating agent, and the block copolymer includes a polymer (A) containing a (meth)acrylic ester monomer and a polymer (B) containing a (meth)acrylamide monomer and has excellent coating formation ability and high adhesive properties to a substrate.

A functional chitosan derivative which comprises a chitin/chitosan, which is a natural polysaccharide, and incorporated therein at least one of a carbohydrate, a photo-reactive functional group, an amphipathic group, e.g. a polyoxyethylene alkyl ether, and a glycosaminoglycan and which, due to the incorporation, has solubility in a neutral medium, self-crosslinking ability, the property of highly containing water or healing wounds, and antithrombotic properties. Namely, the derivative has various properties required of health care materials such as medical products and cosmetics.

Vaso-occlusive devices are provided that have a polymer foam disposed about them. The polymer is treated with a plasma to facilitate thrombogenicity. A method for making and using such devices also is provided. The preferred polymer is a copolymer of a halogenated vinylidene and a halogenated alkene.

The present invention provides a method for treating a thrombotic or an inflammatory disorder administering to a patient in need thereof a therapeutically effective amount of at least one compound of Formula (I) or Formula (V): (I) or a stereoisomer or pharmaceutically acceptable salt or solvate form thereof, wherein the variables A, L, Z, R<3>, R<4>, R<6>, R<11>, X<1>, X<2>, and X<3> are as defined herein. The compounds of Formula (I) are useful as selective inhibitors of serine protease enzymes of the coagulation cascade and/or contact activation system; for example thrombin, factor Xa, factor XIa, factor IXa, factor VIIa and/or plasma kallikrein. In particular, it relates to compounds that are selective factor XIa inhibitors. This invention also provides compounds within the scope of Formula I and relates to pharmaceutical compositions comprising these compounds.

Provided is a surface showing excellent antithrombotic properties. Also provided is a medical device having the same. An antithrombotic surface comprising polymer layers which are in different charged states and alternately layered, characterized by having three-dimensional peaks and valleys formed thereon. The antithrombotic surface as described above which is further characterized in that the peaks and valleys are 15 nm or more but not more than 200 nm in height and depth respectively. A medical device characterized by being provided with the antithrombotic surface as described above. Thus, a thin and highly antithrombotic surface or medical device can be obtained by a relatively convenient method.

A cardiovascular graft is provided with highly reduced thrombogenicity. The cardiovascular graft is an electrospun non-woven mesh produced from supramolecular polymers with large diameter fibers. The cardiovascular graft can be implemented as a vascular graft into the human body to allow vascular bypass/reconstruction, or repeated venous access for dialysis treatment, as well as other disorders of small-diameter blood vessels.