title: Covalently dye-linked, surface-controlled, and bioconjugated organically modified silica nanoparticles as targeted probes for optical imaging.
abstract: In this paper we report the synthesis and characterization of organically modified silica (ORMOSIL) nanoparticles, covalently incorporating the fluorophore rhodamine-B, and surface-functionalized with a variety of active groups. The synthesized nanoparticles are of ultralow size (diameter approximately 20 nm), highly monodispersed, stable in aqueous suspension, and retain the optical properties of the incorporated fluorophore. The surface of the nanoparticles can be functionalized with a variety of active groups such as hydroxyl, thiol, amine, and carboxyl. The carboxyl groups on the surface were used to conjugate with various bioactive molecules such as transferrin, as well as monoclonal antibodies such as anti-claudin 4 and anti-mesothelin, for targeted delivery to pancreatic cancer cell lines. In vitro experiments have revealed that the cellular uptake of these bioconjugated (targeted) nanoparticles is significantly higher than that of the nonconjugated ones. The ease of surface functionalization and incorporation of a variety of biotargeting molecules, combined with their observed noncytotoxicity, makes these fluorescent ORMOSIL nanoparticles potential candidates as efficient probes for optical bioimaging, both in vitro and in vivo.
authors.affiliation: Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260-3000, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Kumar
authors.forename: Indrajit
authors.initials: I
authors.lastname: Roy
authors.forename: Tymish Y
authors.initials: TY
authors.lastname: Ohulchanskyy
authors.forename: Lalit N
authors.initials: LN
authors.lastname: Goswami
authors.forename: Adela C
authors.initials: AC
authors.lastname: Bonoiu
authors.forename: Earl J
authors.initials: EJ
authors.lastname: Bergey
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Tramposch
authors.forename: Anirban
authors.initials: A
authors.lastname: Maitra
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
mesh_terms: D003287:Contrast Media / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008856:Microscopy, Fluorescence / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012235:Rhodamines / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003287:Contrast Media; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D005456:Fluorescent Dyes; D046911:Macromolecular Substances; D012235:Rhodamines; D012822:Silicon Dioxide; C029773:rhodamine B