title: Effect of surface properties on liposomal siRNA delivery.
abstract: Liposomes are one of the most widely investigated carriers for siRNA delivery. The surface properties of liposomal carriers, including the surface charge, PEGylation, and ligand modification can significantly affect the gene silencing efficiency. Three barriers of systemic siRNA delivery (long blood circulation, efficient tumor penetration and efficient cellular uptake/endosomal escape) are analyzed on liposomal carriers with different surface charges, PEGylations and ligand modifications. Cationic formulations dominate siRNA delivery and neutral formulations also have good performance while anionic formulations are generally not proper for siRNA delivery. The PEG dilemma (prolonged blood circulation vs. reduced cellular uptake/endosomal escape) and the side effect of repeated PEGylated formulation (accelerated blood clearance) were discussed. Effects of ligand modification on cationic and neutral formulations were analyzed. Finally, we summarized the achievements in liposomal siRNA delivery, outlined existing problems and provided some future perspectives.
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China.
authors.forename: Yuqiong
authors.initials: Y
authors.lastname: Xia
authors.affiliation: School of Life Science and Technology, Xidian University, Xi'an, Shaanxi, 710071, China; Institute of Automation, Chinese Academy of Sciences, Beijing, 100190, China. Electronic address: tian@ieee.org.
authors.forename: Jie
authors.initials: J
authors.lastname: Tian
authors.affiliation: Laboratory of Molecular Imaging and Nanomedicine (LOMIN), National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH), Bethesda, MD, 20892, USA. Electronic address: shawn.chen@nih.gov.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D020868:Gene Silencing; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D008422:Materials Testing; D011092:Polyethylene Glycols / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry* / Q000235:genetics; D013499:Surface Properties; D014162:Transfection / Q000379:methods*
chemical_list: D008081:Liposomes; D034741:RNA, Small Interfering; D011092:Polyethylene Glycols
keywords: Ligand modification; Liposomes; PEGylation; Surface charge; siRNA delivery