Biocompatible surfaces

Abstract

New phospholipids containing a conjugated di-yne system have the formula: ##STR1## wherein at least one of B.sub.1 and B.sub.2 is a group of the formula --(CO).sub.p --X.sub.1 --C.tbd.C--C.tbd.C--Y.sub.1 wherein p is 0 or 1, X.sub.1 is a direct bond or a divalent aliphatic or cycloaliphatic group, Y.sub.1 is H or a monovalent aliphatic or cycloaliphatic group, the total number of carbon atoms in X.sub.1 and Y.sub.1 in each of B.sub.1 and/or B.sub.2 being 8 to 26; and the other of B.sub.1 and B.sub.2 is either (a) the same or a different group of the formula: --(CO).sub.p --X.sub.1 --C.tbd.C--C.tbd.C--Y.sub.1 where X.sub.1, Y.sub.1 or p are as defined above; or (b) is an aliphatic or cycloaliphatic group containing at least 8 carbon atoms; n is 0 or 1, m is 2, 3 or 4 and each R independently represents an alkyl group containing 1 to 4 carbon atoms, and are prepared by esterification and/or etherification of glycerol by conventional techniques. The conjugated di-yne systems can be cross-linked by actinic radiation to give intermolecular and, in certain cases, also intramolecular cross-linking. Thin layers of the phospholipids can be coated onto substrates subsequently to be brought into contact with blood or other body fluids and then cross-linked to give polymer coated surfaces which have a reduced tendency to initiate blood coagulation, for example, compared to untreated surfaces. Artificial lenses for the human eye treated in this way have a reduced tendency to cause endothelial damage. The phospholipids of the invention can also be formed into liposomes and the conjugated di-yne system then cross-linked. Physiologically active materials such as drugs, enzymes or antigens can be incorporated into the liposomes which can then be used as prolonged release formulations.

Dependencies are inferred from the claim text.