Liposomic drug-delivery vehicles

A liposome comprising:

• a) at least one bilayer-forming lipid;
• b) a polymeric compound having the general formula I:
• wherein:
• m is zero or a positive integer,
• n is an integer which is at least 3,
• Y is a backbone unit which forms a polymeric backbone,
• L is absent or is a linking moiety,
• Z has the general formula II:
• wherein:
• A is a substituted or unsubstituted hydrocarbon;
• B is an oxygen atom or is absent;
• R1-R3 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heteroalicyclic, aryl and heteroaryl, and
• X is a lipid moiety having the general formula III:
• wherein:
• W1 and W2 are each independently selected from the group consisting of hydrogen, alkyl, alkenyl, alkynyl and acyl, wherein at least one of W1 and W2 is not hydrogen;
• J is —P(═O)(OH)—O— or absent;
• K is a substituted or unsubstituted hydrocarbon from 1 to 10 carbon atoms in length, or absent;
• M is a linking group selected from the group consisting of —O—, —S—, amino, sulfinyl, sulfonyl, phosphate, phosphonyl, phosphinyl, carbonyl, thiocarbonyl, urea, thiourea, carbamyl, thiocarbamyl, amido, carboxy, and sulfonamide, or absent;
• and
• Q is a substituted or unsubstituted hydrocarbon from 1 to 10 carbon atoms in length,
• wherein when M is absent, K is also absent,
• wherein at least a portion of said Y, said L and/or said Z comprises at least one targeting moiety;
• and
• c) a therapeutically active agent, incorporated in the liposome and/or on a surface of the liposome,
• wherein said at least one targeting moiety is selected as targeting said therapeutically active agent to a specific bodily site.