title: Transferrin receptor-targeted lipid nanoparticles for delivery of an antisense oligodeoxyribonucleotide against Bcl-2.
abstract: Antisense oligonucleotide G3139-mediated down-regulation of Bcl-2 is a potential strategy for overcoming chemoresistance in leukemia. However, the limited efficacy shown in recent clinical trials calls attention to the need for further development of novel and more efficient delivery systems. In order to address this issue, transferrin receptor (TfR)-targeted, protamine-containing lipid nanoparticles (Tf-LNs) were synthesized as delivery vehicles for G3139. The LNs were produced by an ethanol dilution method, and lipid-conjugated Tf ligand was then incorporated by a postinsertion method. The resulting Tf-LNs had a mean particle diameter of approximately 90 nm and G3139 loading efficiency of 90.4%. Antisense delivery efficiency of Tf-LNs was evaluated in K562, MV4-11, and Raji leukemia cell lines. The results showed that Tf-LNs were more effective than nontargeted LNs and free G3139 (p < 0.05) in decreasing Bcl-2 expression (by up to 62% at the mRNA level in K562 cells) and in inducing caspase-dependent apoptosis. In addition, Bcl-2 down-regulation and apoptosis induced by Tf-LN G3139 were shown to be blocked by excess free Tf and thus were TfR-dependent. Cell lines with higher TfR expression also showed greater Bcl-2 down-regulation. Furthermore, up-regulation of TfR expression in leukemia cells by iron chelator deferoxamine resulted in a further increase in antisense effect (up to 79% Bcl-2 reduction in K562 at the mRNA level) and in caspase-dependent apoptosis (by approximately 3-fold) by Tf-LN. Tf-LN-mediated delivery combined with TfR up-regulation by deferoxamine appears to be a potentially promising strategy for enhancing the delivery efficiency and therapeutic efficacy of antisense oligonucleotides.
authors.affiliation: Division of Pharmaceutics, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Yang
authors.forename: Chee Guan
authors.initials: CG
authors.lastname: Koh
authors.forename: Shujun
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Pan
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Santhanam
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.forename: Yong
authors.initials: Y
authors.lastname: Peng
authors.forename: Jiuxia
authors.initials: J
authors.lastname: Pang
authors.forename: Sharon
authors.initials: S
authors.lastname: Golan
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Talmon
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.forename: Natarajan
authors.initials: N
authors.lastname: Muthusamy
authors.forename: John C
authors.initials: JC
authors.lastname: Byrd
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Chan
authors.forename: L James
authors.initials: LJ
authors.lastname: Lee
authors.forename: Guido
authors.initials: G
authors.lastname: Marcucci
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lee
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D003102:Colloids; D020285:Cryoelectron Microscopy; D015536:Down-Regulation; D016503:Drug Delivery Systems; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020319:Oligodeoxyribonucleotides, Antisense / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010316:Particle Size; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism*; D011990:Receptors, Transferrin / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D003102:Colloids; D008055:Lipids; D020319:Oligodeoxyribonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D011990:Receptors, Transferrin