Improved lipid formulation for the delivery of nucleic acids

摘要

IMPROVED LIPID FORMULATION FOR THE DELIVERY OF NUCLEIC ACIDS Abstract: The invention features an improved lipid formulation comprising a cationic lipid of formula (A), a neutral lipid, a sterol and a PEG or PEG-modified lipid, where R 1 and R 2 are independently alkyl, alkenyl or alkynyl, each can be optionally substituted, and R 3 and R 4 are independently lower alkyl or R 3 and R 4 can be taken together to form an optionally subsituted heterocyclic ring. In one embodiment, R 1 and R 2 are independently selected from oleoyl, pamitoyl, steroyl, linoleyl and R 3 and R 4 are methyl. Also disclosed are targeting lipids, and specific lipid formulations comprising such targeting lipids. N-R4 (A) o 0 1j> R2