title: Targeting vascular endothelium with avidin microbubbles.
abstract: Targeting microbubbles (MBs) to specific vascular beds enables contrast ultrasound to be used for molecular imaging. There are several methods for attaching targeting moieties to the surface of MBs. In the present study, we demonstrate that avidin (Av) can be incorporated into the shell of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) MBs (Av-PESDA-MBs) and serve as an anchor that links Av-PESDA-MBs to biotinylated monoclonal antibodies (mAbs). This novel linking strategy was used to conjugate Av-PESDA-MBs to mAbs specific for endoglin (CD105) or a control IgG. MBs targeted to CD105 specifically bound to endothelial cells, but not to fibroblasts, in vitro but Av-PESDA-MBs conjugated with the control IgG did not specifically target either cell type. We conclude that Av-PESDA-MBs represent a novel and attractive tool to conjugate MBs with biotinylated mAbs for the purposes of vascular targeting and molecular imaging.
authors.affiliation: Hamon Center for Therapeutic Oncology Research, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Korpanty
authors.forename: Paul A
authors.initials: PA
authors.lastname: Grayburn
authors.forename: Ralph V
authors.initials: RV
authors.lastname: Shohet
authors.forename: Rolf A
authors.initials: RA
authors.lastname: Brekken
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001360:Avidin / Q000737:chemistry; D002478:Cells, Cultured; D003287:Contrast Media; D000071063:Endoglin; D004730:Endothelium, Vascular / Q000000981:diagnostic imaging* / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D005434:Flow Cytometry; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology; D051379:Mice; D045423:Microbubbles; D013010:Sonication; D014463:Ultrasonography
chemical_list: D000911:Antibodies, Monoclonal; D003287:Contrast Media; D000071063:Endoglin; C502004:Eng protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D001360:Avidin