title: Ultrasound-based molecular imaging and specific gene delivery to mesenteric vasculature by endothelial adhesion molecule targeted microbubbles in a mouse model of Crohn's disease.
abstract: Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract (GI) for which treatments with immunosuppressive drugs have significant side-effects. Consequently, there is a clinical need for site-specific and non-toxic delivery of therapeutic genes or drugs for CD and related disorders such as inflammatory bowel disease. The aim of this study was to validate a gene delivery platform based on ultrasound-activated lipid-shelled microbubbles (MBs) targeted to inflamed mesenteric endothelium in the CD-like TNFΔARE mouse model. MBs bearing luciferase plasmid were functionalized with antibodies to MAdCAM-1 (MB-M) or VCAM-1 (MB-V), biomarkers of gut endothelial cell inflammation and evaluated in an in vitro flow chamber assay with appropriate ligands to confirm targeting specificity. Following MB retro-orbital injection in TNFΔARE mice, the mean contrast intensity in the ileocecal region from accumulated MB-M and MB-V was 8.5-fold and 3.6-fold greater, respectively, compared to MB-C. Delivery of luciferase plasmid to the GI tract in TNFΔARE mice was achieved by insonating the endothelial cell-bound agents using a commercial sonoporator. Luciferase expression in the midgut was detected 48 h later by bioluminescence imaging and further confirmed by immunohistochemical staining. The liver, spleen, heart, and kidney had no detectable bioluminescence following insonation. Transfection of the microcirculation guided by a targeted, acoustically-activated platform such as an ultrasound contrast agent microbubble has the potential to be a minimally-invasive treatment strategy to ameliorate CD and other inflammatory conditions.
authors.affiliation: Department of Biomedical Engineering, School of Engineering and Applied Science, University of Virginia, Charlottesville, VA, United States.
authors.forename: José L
authors.initials: JL
authors.lastname: Tlaxca
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Rychak
authors.forename: Peter B
authors.initials: PB
authors.lastname: Ernst
authors.forename: Prasad R
authors.initials: PR
authors.lastname: Konkalmatt
authors.forename: Talent I
authors.initials: TI
authors.lastname: Shevchenko
authors.forename: Theresa T
authors.initials: TT
authors.lastname: Pizarro
authors.forename: Theresa T
authors.initials: TT
authors.lastname: Pizzaro
authors.forename: Jesús
authors.initials: J
authors.lastname: Rivera-Nieves
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Klibanov
authors.forename: Michael B
authors.initials: MB
authors.lastname: Lawrence
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003424:Crohn Disease / Q000000981:diagnostic imaging / Q000378:metabolism*; D004247:DNA / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D018014:Gene Transfer Techniques; D049409:Luciferases, Firefly / Q000235:genetics / Q000378:metabolism; D008643:Mesentery / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D045423:Microbubbles; D057054:Molecular Imaging; D009088:Mucoproteins; D010957:Plasmids; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D014463:Ultrasonography; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
chemical_list: D015815:Cell Adhesion Molecules; C489082:Madcam1 protein, mouse; D009088:Mucoproteins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D004247:DNA; D049409:Luciferases, Firefly