title: Slow intracellular trafficking of catalase nanoparticles targeted to ICAM-1 protects endothelial cells from oxidative stress.
abstract: Nanotechnologies promise new means for drug delivery. ICAM-1 is a good target for vascular immunotargeting of nanoparticles to the perturbed endothelium, although endothelial cells do not internalize monomeric anti-ICAM-1 antibodies. However, coupling ICAM-1 antibodies to nanoparticles creates multivalent ligands that enter cells via an amiloride-sensitive endocytic pathway that does not require clathrin or caveolin. Fluorescence microscopy revealed that internalized anti-ICAM nanoparticles are retained in a stable form in early endosomes for an unusually long time (1-2 h) and subsequently were degraded following slow transport to lysosomes. Inhibition of lysosome acidification by chloroquine delayed degradation without affecting anti-ICAM trafficking. Also, the microtubule disrupting agent nocodazole delayed degradation by inhibiting anti-ICAM nanoparticle trafficking to lysosomes. Addition of catalase to create anti-ICAM nanoparticles with antioxidant activity did not affect the mechanisms of nanoparticle uptake or trafficking. Intracellular anti-ICAM/catalase nanoparticles were active, because endothelial cells were resistant to H2O2-induced oxidative injury for 1-2 h after nanoparticle uptake. Chloroquine and nocodazole increased the duration of antioxidant protection by decreasing the extent of anti-ICAM/catalase degradation. Therefore, the unique trafficking pathway followed by internalized anti-ICAM nanoparticles seems well suited for targeted delivery of therapeutic enzymes to endothelial cells and may provide a basis for treatment of acute vascular oxidative stress.
authors.affiliation: Institute for Environmental Medicine, University of Pennsylvania School of Medicine, 1 John Morgan/6068, 3620 Hamilton Walk, Philadelphia, PA 19104, USA.
authors.forename: Silvia
authors.initials: S
authors.lastname: Muro
authors.forename: Xiumin
authors.initials: X
authors.lastname: Cui
authors.forename: Christine
authors.initials: C
authors.lastname: Gajewski
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Murciano
authors.forename: Vladimir R
authors.initials: VR
authors.lastname: Muzykantov
authors.forename: Michael
authors.initials: M
authors.lastname: Koval
mesh_terms: D002374:Catalase / Q000008:administration & dosage*; D002478:Cells, Cultured; D016503:Drug Delivery Systems / Q000379:methods*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000201:enzymology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D007424:Intracellular Fluid / Q000187:drug effects; D036103:Nanotechnology / Q000379:methods; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology
chemical_list: D018799:Intercellular Adhesion Molecule-1; D002374:Catalase