Patent ID: 7982027

Claim:
A nucleic acid-lipid particle, said nucleic acid-lipid particle comprising: a chemically synthesized siRNA; a cationic lipid; a non-cationic lipid; and a conjugated lipid that inhibits aggregation of particles, wherein the conjugated lipid that inhibits aggregation of particles comprises a polyethyleneglycol-dialkyloxypropyl (PEG-DAA) conjugate having the following structure: wherein: R 1 and R 2 are independently selected and are alkyl groups having from about 10 to about 22 carbon atoms; PEG is a polyethyleneglycol, wherein the terminal hydroxyl group is substituted with a methyl group; and L is a carbamate linker moiety; and wherein said siRNA is fully encapsulated in said nucleic acid-lipid particle.