title: Protease-triggered siRNA delivery vehicles.
abstract: The safe and efficacious delivery of membrane impermeable therapeutics requires cytoplasmic access without the toxicity of nonspecific cytoplasmic membrane lysis. We have developed a mechanism for control of cytoplasmic release which utilizes endogenous proteases as a trigger and results in functional delivery of small interfering RNA (siRNA). The delivery approach is based on reversible inhibition of membrane disruptive polymers with protease-sensitive substrates. Proteolytic hydrolysis upon endocytosis restores the membrane destabilizing activity of the polymers thereby allowing cytoplasmic access of the co-delivered siRNA. Protease-sensitive polymer masking reagents derived from polyethylene glycol (PEG), which inhibit membrane interactions, and N-acetylgalactosamine, which targets asialoglycoprotein receptors on hepatocytes, were synthesized and used to formulate masked polymer-siRNA delivery vehicles. The size, charge and stability of the vehicles enable functional delivery of siRNA after subcutaneous administration and, with modification of the targeting ligand, have the potential for extrahepatic targeting.
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA. Electronic address: dave.rozema@arrowres.com.
authors.forename: David B
authors.initials: DB
authors.lastname: Rozema
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Blokhin
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Darren H
authors.initials: DH
authors.lastname: Wakefield
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Benson
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Carlson
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Klein
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Almeida
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Nicholas
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Holly L
authors.initials: HL
authors.lastname: Hamilton
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Qili
authors.initials: Q
authors.lastname: Chu
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Julia O
authors.initials: JO
authors.lastname: Hegge
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: So C
authors.initials: SC
authors.lastname: Wong
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Vladimir S
authors.initials: VS
authors.lastname: Trubetskoy
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Collin M
authors.initials: CM
authors.lastname: Hagen
authors.affiliation: F. Hoffmann-La Roche Ltd., Pharma Research and Early Development Discovery Chemistry, Roche Innovation Center Basel, Grenzacherstrasse 124, CH-4070 Basel, Switzerland.
authors.forename: Eric
authors.initials: E
authors.lastname: Kitas
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: Jon A
authors.initials: JA
authors.lastname: Wolff
authors.affiliation: Arrowhead Research Corporation, Arrowhead Madison, 465 Science Drive, Madison, WI 53711, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Lewis
mesh_terms: D000818:Animals; D004912:Erythrocytes / Q000187:drug effects; D005167:Factor VII / Q000235:genetics*; D005260:Female; D018014:Gene Transfer Techniques; D006461:Hemolysis / Q000187:drug effects; D008252:Macaca fascicularis; D008297:Male; D008813:Mice, Inbred ICR; D010447:Peptide Hydrolases / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000737:chemistry; D051381:Rats
chemical_list: D011108:Polymers; D034741:RNA, Small Interfering; D005167:Factor VII; D010447:Peptide Hydrolases
keywords: Subcutaneous; Targeted delivery; siRNA polymer conjugate