摘要 |
New phospholipids containing a conjugated di-yne system have the formula: <IMAGE> wherein at least one of B1 and B2 is a group of the formula -(CO)p-X1-C 3BOND C-C 3BOND C-Y1 wherein p is 0 or 1, X1 is a direct bond or a divalent aliphatic or cycloaliphatic group, Y1 is H or a monovalent aliphatic or cycloaliphatic group, the total number of carbon atoms in X1 and Y1 in each of B1 and/or B2 being 8 to 26; and the other of B1 and B2 is either (a) the same or a different group of the formula: -(CO)p-X1-C 3BOND C-C 3BOND C-Y1 where X1, Y1 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. |