Upconverting nanoparticles are attracting extensive interest as a multimodal imaging tool. In this work, we report on the synthesis and characterization of gadolinium-enriched upconverting nanoparticles for bimodal magnetic resonance and optical luminescence imaging. NaYF4:Gd3+,Yb3+,Tm3+ core upconverting nanoparticles were obtained by a thermal coprecipitation of lanthanide oleate precursors in the presence of oleic acid as a stabilizer. With the aim of improving the upconversion emission and increasing the amount of Gd3+ ions on the nanoparticle surface, a 2.5 nm NaGdF4 shell was grown by the epitaxial layer-by-layer strategy, resulting in the 26 nm core-shell nanoparticles. Both core and core-shell nanoparticles were coated with poly(ethylene glycol) (PEG)-neridronate (PEG-Ner) to have stable and well-dispersed upconverting nanoparticles in a biological medium. FTIR spectroscopy and thermogravimetric analysis indicated the presence of ∼20 wt % of PEG-Ner on the nanoparticle surface. The addition of inert NaGdF4 shell resulted in a total 26-fold enhancement of the emission under 980 nm excitation and also affected the T 1 and T 2 relaxation times. Both r 1 and r 2 relaxivities of PEG-Ner-modified nanoparticles were much higher compared to those of non-PEGylated particles, thus manifesting their potential as a diagnostic tool for magnetic resonance imaging. Together with the enhanced luminescence efficiency, upconverting nanoparticles might represent an efficient probe for bimodal in vitro and in vivo imaging of cells in regenerative medicine, drug delivery, and/or photodynamic therapy.

• Publikační typ
• časopisecké články MeSH

Over the last few years, the development and relevance of 19F magnetic resonance imaging (MRI) for use in clinical practice has emerged. MRI using fluorinated probes enables the achievement of a specific signal with high contrast in MRI images. However, to ensure sufficient sensitivity of 19F MRI, fluorine probes with a high content of chemically equivalent fluorine atoms are required. The majority of 19F MRI agents are perfluorocarbon emulsions, which have a broad range of applications in molecular imaging, although the content of fluorine atoms in these molecules is limited. In this review, we focus mainly on polymer probes that allow higher fluorine content and represent versatile platforms with properties tailorable to a plethora of biomedical in vivo applications. We discuss the chemical development, up to the first imaging applications, of these promising fluorine probes, including injectable polymers that form depots that are intended for possible use in cancer therapy.

• Klíčová slova
• 19F MRI probe, Fluorine, Magnetic resonance imaging (MRI), Molecular imaging, Polymer,
• MeSH
• fluor chemie   MeSH
• fluorokarbony chemie   MeSH
• koncentrace vodíkových iontů MeSH
• kontrastní látky chemie   MeSH
• lidé MeSH
• molekulární sondy chemie   MeSH
• molekulární zobrazování přístrojové vybavení   metody   MeSH
• myši MeSH
• polymery chemie   MeSH
• radiační rozptyl MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• světlo MeSH
• teplota MeSH
• zobrazování fluorovou magnetickou rezonancí metody   trendy   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• fluor MeSH
• fluorokarbony MeSH
• kontrastní látky MeSH
• molekulární sondy MeSH
• polymery MeSH
• reaktivní formy kyslíku MeSH