Next Article in Journal
Comparing the Acidity of (R3P)2BH-Based Donor Groups in Iridium Pincer Complexes
Next Article in Special Issue
Unconventional Anticancer Metallodrugs and Strategies to Improve Their Pharmacological Profile
Previous Article in Journal
Potential of MRI in Radiotherapy Mediated by Small Conjugates and Nanosystems
Previous Article in Special Issue
Designing Ruthenium Anticancer Drugs: What Have We Learnt from the Key Drug Candidates?
Open AccessCommunication

Functionalizing NaGdF4:Yb,Er Upconverting Nanoparticles with Bone-Targeting Phosphonate Ligands: Imaging and In Vivo Biodistribution

CIC biomaGUNE, Paseo de Miramón 182, 20014 Donostia, Spain
Donostia International Physics Center (DIPC), Manuel Lardizabal Ibilbidea 4, 20018 Donostia, Spain
Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
Authors to whom correspondence should be addressed.
Current address: BASF SE, Department of Material Physics & Analytics, Carl-Bosch-Strasse 38, 67056 Ludwigshafen, Germany.
Inorganics 2019, 7(5), 60;
Received: 11 December 2018 / Revised: 12 April 2019 / Accepted: 19 April 2019 / Published: 30 April 2019
Lanthanide-doped upconverting nanoparticles (UCNPs) transform near infrared light (NIR) into higher-energy UV and visible light by multiphotonic processes. Owing to such unique feature, UCNPs have found application in optical imaging and have been investigated for the NIR light activation of prodrugs, including transition metal complexes of interest in photochemotherapy. Besides, UCNPs also function as magnetic resonance imaging (MRI) contrast agents and positron emission tomography (PET) probes when labelled with radionuclides such as 18F. In this contribution, we report on a new series of phosphonate-functionalized NaGdF4:Yb,Er UCNPs that show affinity for hydroxyapatite (inorganic constituent of bones), and we discuss their potential as bone targeting multimodal (MRI/PET) imaging agents. In vivo biodistribution studies of 18F-labelled NaGdF4:Yb,Er UCNPs in rats indicate that surface functionalization with phosphonates favours the accumulation of nanoparticles in bones over time. PET results reveal leakage of 18F for phosphonate-functionalized NaGdF4:Yb,Er and control nanomaterials. However, Gd was detected in the femur for phosphonate-capped UCNPs by ex vivo analysis using ICP-MS, corresponding to 6–7% of the injected dose. View Full-Text
Keywords: upconverting nanoparticles; phosphonates; bones; imaging; MRI; PET upconverting nanoparticles; phosphonates; bones; imaging; MRI; PET
Show Figures

Graphical abstract

MDPI and ACS Style

Alonso-de Castro, S.; Ruggiero, E.; Lekuona Fernández, A.; Cossío, U.; Baz, Z.; Otaegui, D.; Gómez-Vallejo, V.; Padro, D.; Llop, J.; Salassa, L. Functionalizing NaGdF4:Yb,Er Upconverting Nanoparticles with Bone-Targeting Phosphonate Ligands: Imaging and In Vivo Biodistribution. Inorganics 2019, 7, 60.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop