title: Monoclonal antibody-targeted fluorescein-5-isothiocyanate-labeled biomimetic nanoapatites: a promising fluorescent probe for imaging applications.
abstract: Multifunctional biomimetic nanoparticles (NPs) are acquiring increasing interest as carriers in medicine and basic research since they can efficiently combine labels for subsequent tracking, moieties for specific cell targeting, and bioactive molecules, e.g., drugs. In particular, because of their easy synthesis, low cost, good biocompatibility, high resorbability, easy surface functionalization, and pH-dependent solubility, nanocrystalline apatites are promising candidates as nanocarriers. This work describes the synthesis and characterization of bioinspired apatite nanoparticles to be used as fluorescent nanocarriers targeted against the Met/hepatocyte growth factor receptor, which is considered a tumor associated cell surface marker of many cancers. To this aim the nanoparticles have been labeled with Fluorescein-5-isothiocyanate (FITC) by simple isothermal adsorption, in the absence of organic, possibly toxic, molecules, and then functionalized with a monoclonal antibody (mAb) directed against such a receptor. Direct labeling of the nanoparticles allowed tracking the moieties with spatiotemporal resolution and thus following their interaction with cells, expressing or not the targeted receptor, as well as their fate in vitro. Cytofluorometry and confocal microscopy experiments showed that the functionalized nanocarriers, which emitted a strong fluorescent signal, were rapidly and specifically internalized in cells expressing the receptor. Indeed, we found that, once inside the cells expressing the receptor, mAb-functionalized FITC nanoparticles partially dissociated in their two components, with some mAbs being recycled to the cell surface and the FITC-labeled nanoparticles remaining in the cytosol. This work thus shows that FITC-labeled nanoapatites are very promising probes for targeted cell imaging applications.
authors.affiliation: Dipartimento di Scienze della Salute, Università del Piemonte Orientale "Amedeo Avogadro" , Via Solaroli 17, 28100 Novara, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Oltolina
authors.forename: Luca
authors.initials: L
authors.lastname: Gregoletto
authors.forename: Donato
authors.initials: D
authors.lastname: Colangelo
authors.forename: Jaime
authors.initials: J
authors.lastname: Gómez-Morales
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Delgado-López
authors.forename: Maria
authors.initials: M
authors.lastname: Prat
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology; D001031:Apatites / Q000737:chemistry*; D001692:Biological Transport; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D045744:Cell Line, Tumor; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008422:Materials Testing; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D019859:Proto-Oncogene Proteins c-met / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D001031:Apatites; D005456:Fluorescent Dyes; D019859:Proto-Oncogene Proteins c-met; D016650:Fluorescein-5-isothiocyanate