Lipid analogs and liposomes comprising same

A polymeric compound having the general formula I:

• wherein:
• m is zero or a positive integer;
• n is an integer which is at least 1, wherein when X does not comprise a phosphate group, n is at least 2;
• X is a lipid moiety;
• Y is a backbone unit which forms a polymeric backbone;
• L is absent or is a linking moiety;
• and
• Z has the general formula II:
• wherein:
• A is a substituted or unsubstituted hydrocarbon;
• B is an oxygen atom or is absent;
• and
• R1-R3 are each independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, heteroalicyclic, aryl and heteroaryl,
• and wherein:
• a) said lipid is selected from the group consisting of a fatty acid, a monoglyceride, a glycerophospholipid, and a sphingolipid, and/or
• b) X has 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;
• 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, or absent,
• wherein when M is absent, Q is also absent.