title: In vivo evaluation of magnetite nanoparticles for use as a tumor contrast agent in MRI.
abstract: Magnetite nanoparticles, coated by three different artificial polypeptides, were conjugated to an antibody specific to the carcinoembryonic antigen (CEA). To protect the particles from fast blood elimination, the coats were modified by various sugars, polyethyleneglycol, albumin, and sialoproteins, respectively. The protective effect was determined by using a specific in vitro test and by analyzing the biodistribution of the nanoparticles in nude mice grafted with CEA-tumors. In particular, a prolongation of the blood circulation time has been expected, if a natural modifier is attached to the coated nanoparticles. Although the elimination rate could hardly be decreased by any modifiers, the tumor accumulation is slightly improved by using the specific sialoprotein glycophorin B. The usefulness of nanoparticles as image contrast agents is probably limited by their microdistribution within the tumor tissue. The requirements for a contrast agent to be highly tissue specific are discussed.
authors.affiliation: Paul Scherrer Institut, Villigen, Switzerland.
authors.forename: L X
authors.initials: LX
authors.lastname: Tiefenauer
authors.forename: A
authors.initials: A
authors.lastname: Tschirky
authors.forename: G
authors.initials: G
authors.lastname: Kühne
authors.forename: R Y
authors.initials: RY
authors.lastname: Andres
mesh_terms: D000818:Animals; D000918:Antibody Specificity; D002272:Carcinoembryonic Antigen / Q000276:immunology; D003287:Contrast Media / Q000493:pharmacokinetics; D052203:Ferrosoferric Oxide; D005947:Glucose; D005965:Glucuronates; D020723:Glucuronic Acid; D006021:Glycophorins; D007501:Iron / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D051379:Mice; D008819:Mice, Nude; D019158:N-Acetylneuraminic Acid; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000175:diagnosis*; D010087:Oxides / Q000493:pharmacokinetics; D011092:Polyethylene Glycols; D011108:Polymers; D012709:Serum Albumin; D013387:Succinic Anhydrides; D013499:Surface Properties; D014018:Tissue Distribution
chemical_list: D002272:Carcinoembryonic Antigen; D003287:Contrast Media; D005965:Glucuronates; D006021:Glycophorins; D010087:Oxides; D011108:Polymers; D012709:Serum Albumin; D013387:Succinic Anhydrides; D011092:Polyethylene Glycols; C031801:succinic anhydride; D020723:Glucuronic Acid; D007501:Iron; D019158:N-Acetylneuraminic Acid; D005947:Glucose; D052203:Ferrosoferric Oxide