Limitations of Cationic Liposomes for Antisense Oligonucleotide Delivery in Vivo

Much attention has focused on cationic liposomes for delivery of antisense oligonucleotides. While these reagents demonstrate efficient delivery and potentiation of antisense oligonucleotides in vitro under serum-free conditions, then-use in vivo may be limited. This report highlights issues including serum-instability, biodistribution, and target-nonspecificity that may hinder their use for efficient nucleic acid delivery in vivo. Given the many advantages of liposomes for drug delivery, alternative liposome formulations of nucleic acid are discussed.