Abstract: An article of metal, glass, ceramics or plastics having a surface for contact with tissue or with circulating blood, has a surface coating of an organopolysiloxane and heparin, in which coating the organopolysiloxane is adherent to the surface of the article and has cationic groups that form ionic bonds with anionic groups of the heparin. The surface for contact with circulating blood may be an interior surface of a cannula or tubing or of a blood oxygenator or it may be a working surface of a blood filter. The polymer may be poly-[dimethylsiloxane-co-methyl-(3-hydroxypropyl)siloxane]-graft-poly(ethylene glycol) [3-(trimethylammonio) propyl chloride] ether.

Abstract: A metal, glass or ceramics surface is treated to enhance its compatibility with biological material such as blood or blood related products. Treatment involves covalently bonding to the surface by means of a catalyst functional molecules each of has at least one alkoxysilane group which can form at least one first covalent bond by reaction with the oxide or hydroxide of said surface and at least one other group which can participate in free-radical polymerisation. Free-radical polymerisation from said functional molecules is then effected to build bio-compatible and/or hydrophilic polymer chains. The compatibility of the metal surface with biological material may be further improved by bonding bio-active molecules, such as heparin or heparin derived molecules to the polymer chains. Suitable metal surfaces are those of medical devices such as heat exchangers, coronary and peripheral stents and guide wires used in angioplasty.

Abstract: An article of metal, glass, ceramics or plastics having a surface for contact with tissue or with circulating blood, has a surface coating of an organopolysiloxane and heparin, in which coating the organopolysiloxane is adherent to the surface of the article and has cationic groups that form ionic bonds with anionic groups of the heparin. The surface for contact with circulating blood may be an interior surface of a cannula or tubing or of a blood oxygenator or it may be a working surface of a blood filter. The polymer may be poly-[dimethylsiloxane-co-methyl-(3-hydroxypropyl)siloxane]-graft-poly(ethylene glycol) [3-(trimethylammonio) propyl chloride] ether.