title: VCAM-1 specific PEGylated SAINT-based lipoplexes deliver siRNA to activated endothelium in vivo but do not attenuate target gene expression.
abstract: In recent years much research in RNA nanotechnology has been directed to develop an efficient and clinically suitable delivery system for short interfering RNA (siRNA). The current study describes the in vivo siRNA delivery using PEGylated antibody-targeted SAINT-based-lipoplexes (referred to as antibody-SAINTPEGarg/PEG2%), which showed superior siRNA delivery capacity and effective down-regulation of VE-cadherin gene expression in vitro in inflammation-activated primary endothelial cells of different vascular origins. PEGylation of antibody-SAINTPEGarg resulted in more desirable pharmacokinetic behavior than that of non-PEGylated antibody-SAINTPEGarg. To create specificity for inflammation-activated endothelial cells, antibodies against vascular cell adhesion molecule-1 (VCAM-1) were employed. In TNFα-challenged mice, these intravenously administered anti-VCAM-1-SAINTPEGarg/PEG2% homed to VCAM-1 protein expressing vasculature. Confocal laser scanning microscopy revealed that anti-VCAM-1-SAINTPEGarg/PEG2% co-localized with endothelial cells in lung postcapillary venules. Furthermore, they did not exert any liver and kidney toxicity. Yet, lack of in vivo gene silencing as assessed in whole lung and in laser microdissected lung microvascular segments indicates that in vivo internalization and/or intracellular trafficking of the delivery system and its cargo in the target cells are not sufficient, and needs further attention, emphasizing the essence of evaluating siRNA delivery systems in an appropriate in vivo animal model at an early stage in their development.
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands.
authors.forename: Niek G J
authors.initials: NG
authors.lastname: Leus
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands.
authors.forename: Henriëtte W M
authors.initials: HW
authors.lastname: Morselt
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Zwiers
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands.
authors.forename: Piotr S
authors.initials: PS
authors.lastname: Kowalski
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands; Synvolux Therapeutics, Groningen, the Netherlands.
authors.forename: Marcel H J
authors.initials: MH
authors.lastname: Ruiters
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands.
authors.forename: Grietje
authors.initials: G
authors.lastname: Molema
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pathology & Medical Biology, Medical Biology section, Laboratory for Endothelial Biomedicine & Vascular Drug Targeting Research, Groningen, the Netherlands. Electronic address: j.a.a.m.kamps@umcg.nl.
authors.forename: Jan A A M
authors.initials: JA
authors.lastname: Kamps
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry / Q000378:metabolism*; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000276:immunology / Q000378:metabolism*; D005786:Gene Expression Regulation; D007249:Inflammation / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D008055:Lipids / Q000737:chemistry*; D008168:Lung / Q000098:blood supply*; D008297:Male; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D011092:Polyethylene Glycols / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution; D014162:Transfection / Q000379:methods*; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1 / Q000276:immunology / Q000378:metabolism*; D014699:Venules / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D000906:Antibodies; D015703:Antigens, CD; D015820:Cadherins; D008055:Lipids; D011092:Polyethylene Glycols; D011726:Pyridinium Compounds; D034741:RNA, Small Interfering; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D000099152:Cadherin 5; C532953:1-methyl-4-(9-dioleyl)methylpyridinium
keywords: Cationic lipid; Endothelial cells; Inflammation; Targeted delivery; Vascular cell adhesion molecule-1; siRNA