Abstract: Disclosed is a polymer blend composition and shaped article, and a process of blending and making shaped articles of polymer blends in which the biocompatibility of various polymers is improved by blending with them a polymer including a zwitterionic group. The zwitterionic group is usually an ammonium phosphate ester, preferably a choline, zwitterionic group and the polymer containing it may be produced by the free radical polymerization of ethylenically unsaturated monomers including a monomer bearing the zwitterionic group. Blending of the two polymers may be achieved by dry blending particulate polymers or by mixing the polymers in liquid dispersion or solution followed by removal of the liquid medium. The fibrinogen absorption and/or platelet activation of polymers may be reduced to a value of less than 80% or even less than 60% of the base polymer by introducing amounts of more than 10% or more than 30% of the zwitterionic group containing polymer.

Abstract: A non-crosslinked polymer having pendant zwitterionic groups and pendant functional groups can be coated from a coating composition onto a surface having pendant coreactive functional groups and, after coating, may be cured so that covalent bonds are formed between the coreactive functional groups on the polymer and the surface. Alternatively the polymer can be crosslinked after coating, by formation of covalent intermolecular cross-links between coreactive pendant functional groups on the polymer. The zwitterionic pendant groups preferably have, as the anion, a phosphate ester group, and as the cation, a quaternary ammonium group. The polymer coating is stable and provides improved biocompatibility, especially haemocompatibility.

Abstract: Polymers of one or more radical polymerisable monomers which polymer has pendant groups bearing a centre of permanent positive charge and other pendant groups capable of stably binding the polymer to a surface are useful in the treatment of surfaces to render them biocompatible. The polymers may contain pendant groups which bind the polymer to a surface by physisorption, covalent bonding or ionic interactions. Additionally reactive groups in the polymer may serve as points for attachment of ligands to the polymer when coated on a surface.

Abstract: A braided stent (1) for transluminal implantation in body lumens is self-expanding and has a radial expanded configuration in which the angle .alpha. between filaments is acute. Some or all of filaments (6,7) are welded together in pairs at each end (4,5) of the stent to provide beads (8), thereby strengthening the stent and assisting its deployment from a delivery device. The stent is preferably completely coated using a biocompatible polymeric coating, said polymer preferably having pendant phosphoryl choline groups. A method of making the stent by braiding and welding is described as well as a delivery device for deploying the device.

Abstract: A method of reducing the extent to which microorganisms, particularly bacteria, will adhere to a surface, which comprises providing a surface having pendant groups of formula (I), in which each group R is the same or different and is alkyl of 1 to 4 carbon atoms and a is from 1 to 4, use of compounds containing a group of formula (I) in reducing the extent to which microorganisms would adhere to a surface and use of articles comprising such surfaces in environments susceptible to microorganism adhesion. The method has application in a wide variety of industrial or domestic fields wherever it is desirable to prevent growth of microorganisms as well as in the medical field.

Abstract: Polymers of one or more radical polymerisable monomers which polymer has pendant groups bearing a centre of permanent positive charge and other pendant groups capable of stably binding the polymer to a surface are useful in the treatment of surfaces to render them biocompatible. The polymers may contain pendant groups which bind the polymer to a surface by physisorption, covalent bonding or ionic interactions. Additionally reactive groups in the polymer may serve as points for attachment of ligands to the polymer when coated on a surface.

Abstract: An improved process for producing ethylenically unsaturated phosphate ester compounds, especially 2-(methacryloyloxyethyl)-2' (trimethylammoniomethyl) phosphate, (HEMA-PC) comprises a two step reaction in the first of which a phospholane reagent is reacted with a hydroxyl containing ethylenically unsaturated starting material, and in the second of which the intermediate formed in the first step is ring opened by reaction with trimethylamine to produce a zwitterionic product. In the process the two steps of the reaction are carried out in the same solvent with substantially no removal or addition of solvent after the first step. The solvent is preferably acetonitrile. The use of pure reagents avoids the production of undesirable by-products. The product is suitable for polymerising, for instance to provide cross-linked hydrogel copolymers used in ophthalmic applications.

Abstract: New materials having improved biocompatibility have novel zwitterionic groups at the surface. The zwitterion is characterized by having at least one monovalent substituent at the atom carrying the cationic charge which is an aryl group. Preferably the atom carries at least two, and preferably three such aryl, usually phenyl, groups. The cationic group is preferably a triphenylphosphonium. Treatment of surfaces to provide pendant zwitterionic groups of the specified type have reduced platelet activation, whilst they do not appear to reduce platelet adhesion. The invention has utility in the field of blood contacting device, especially devices for implantation, such as vascular grafts.

Abstract: Polymers of one or more radical polymerisable monomers which polymer has pendant groups bearing a center of permanent positive charge and other pendant groups capable of stably binding the polymer to a surface are useful in the treatment of surfaces to render them biocompatible. The polymers may contain pendant groups which bind the polymer to a surface by physisorption, covalent bonding or ionic interactions. Additionally reactive groups in the polymer may serve as points for attachment of ligands to the polymer when coated on a surface.

Abstract: The present invention relates to materials which comprise a surface having pendant groups of formula (I), in which the groups --B-- are the same or different, preferably the same, and each is --CH.sub.2 -- or --C(.dbd.O)--, preferably --CH.sub.2 --, R.sup.1 is hydrogen alkyl of 1 to 12, preferably 1 to 4 carbon atoms, or a group capable of bonding to, or bonded to, a ligand or R.sup.1 is a polymerisable, preferably ethylenically unsaturated, group and Z is a zwitterionic group. Usually both groups B are the same and are joined to identical groups so that the compound of formula (I) is achiral. New compounds are achiral glyceryl phosphatidyl choline analogues. Surfaces having the groups (I) at their surface have improved biocompatibility, and show reduced fibrinogen absorption, reduced platelet activation, reduced microorganism adhesion and are useful in the production of implants or prostheses, for extra-corporeal circuitry for body fluids, for treating membranes of various type, for contact lenses.

Abstract: The biocompatibility of various polymers is improved by blending with them a polymer including a zwitterionic group. The zwitterionic group is usually an ammonium phosphate ester zwitterionic group and the polymer containing it may be produced by the free radical polymerisation of ethylenically unsaturated monomers including a monomer bearing the zwitterionic group. Blending of the two polymers may be achieved by dry blending particulate polymers or by mixing the polymers in liquid dispersion or solution followed by removal of the liquid medium. The fibrinogen absorption and/or platelet activation of polymers may be reduced to a value of less than 80% or even less than 60% of the base polymer by introducing amounts of more than 10% or mare than 30% of the zwitterionic group containing polymer. Preferred blends are of copolymers of 2-(methacryloyloxyethyl)-2'-(trimethylammonium)ethyl phosphate inner salt with higher alkyl (meth) acrylate, blended with olefin polymers and/or with rubber latices.

Abstract: Polymers of one or more radical polymerisable monomers which polymer has pendant groups bearing a center of permanent positive charge and other pendant groups capable of stably binding the polymer to a surface are useful in the treatment of surfaces to render them biocompatible. The polymers may contain pendant groups which bind the polymer to a surface by physisorption, covalent bonding or ionic interactions. Additionally reactive groups in the polymer may serve as points for attachment of ligands to the polymer when coated on a surface.

Abstract: A method of producing a material bearing zwitterionic groups, such as phosphoryl choline groups, which comprises treating at least the surface of a substrate with a solution or dispersion of a polymer grafter with zwitterionic groups, and material produced by the method. The method is suitable for producing materials for use in contact with blood and in particular a regenerated cellulose membrane.

Abstract: Polymers of one or more radical polymerizable monomers which polymer has pendant groups bearing a center of permanent positive charge and other pendant groups capable of stably binding the polymer to a surface are useful in the treatment of surfaces to render them biocompatible. The polymers may contain pendant groups which bind the polymer to a surface by physisorption, covalent bonding or ionic interactions. Additionally reactive groups in the polymer may serve as points for attachment of ligands to the polymer when coated on a surface.

Abstract: The present invention provides materials which comprise a surface having pendant zwitterionic groups Z comprising, as anion, a phosphate, sulphonate, carboxylate or phosphate-ester group or a phosphate ester group in which one or more of the ester oxygen atoms is replaced by --S--, --NH-- or by a valence bond and, as cation, an ammonium, phosphonium or sulphonium moiety, provided that where the anion is a phosphate-ester group or derivative thereof or sulphonate and the cation is a trialkyl quaternary ammonium group (the alkyl groups each containing from 1 to 4 carbon atoms) and the group linking the anion and cation moieties is an alkylene group, the alkylene group, contains at least 5, preferably at least 6, and more preferably at least 7, carbon atoms. The materials have improved biocompatibility for instance as evidenced by reduced protein deposition and reduced platelet activation.

Abstract: Plastics materials may be plasticized using lipids as the sole plasticizer or in combination with conventional plasticizers. When appropriate lipids are used thermosetting plastics and elastomers may be rendered biocompatible or therapeutic articles and substained release medicaments may be formed.

Abstract: A process for the preparation of compounds of formula (I) in which Z is hydrogen or --NHZ is an activated amine group capable of reacting with a surface, the groups R are the same or different and each is a straight or branched C.sub.1 -C.sub.4 alkyl group, preferably methyl, n is from 2 to 6, and X is a straight or branched C.sub.1-20 alkylene group, or X is a group of formula --(CH.sub.2 CH.sub.2 O).sub.b --, or --(CH.sub.2).sub.c --Ar--(CH.sub.2).sub.d -- where b is from 1 to 20, c and d are the same or different and each is from 0 to 5, and Ar is a para- or meta- disubstituted phenyl group (preferably a para-disubstituted phenyl group) which is optionally further substituted by one or more C.sub.1 -C.sub.4 alkyl groups, or an acid addition salt thereof or a hydrate thereof, new compounds of formula (I) and salts and hydrates thereof and the use of compounds of formula (I) and salts and hydrates thereof in treating surfaces to render them more biocompatible.

Abstract: Compounds of formula (I), in which the groups R are hydrogen or C.sub.1-4 alkyl, n is from 2 to 4, X is alkylene, poly(ethoxy) or an aryl-containing group, Y is a valence bond or a divalent functional or heterocyclic group or a trivalent alkylene group, and Z is a sulphur-containing group which contains a thiol or disulphide group are useful to provide biocompatible treatments of metal surfaces, such as silver and gold surfaces. Processes for the preparation of the compounds, intermediates useful in such processes, articles having a metal surface treated with such compounds and processes of rendering metal surfaces biocompatible which comprise treating the metal surfaces with them.

Abstract: A process for coating a surface comprising applying a solution containing a polymer obtained by polymerizing a phospholipid of the following formula (I): ##STR1##