NM03.11.26 : A Label Free Monophosphonated-Carbon Dots for Selective In Vivo Fluorescence Imaging of Bone Microcracks

5:00 PM–7:00 PM Apr 5, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Fatemeh Ostadhossein1 Lily Benig1 Indu Tripathi1 Santosh Kumar Misra1 Dipanjan Pan1

1, University of Illinois at Urbana-Champagin, Urbana, Illinois, United States

Phosphonated compounds, in particular, bis-analogs are widely applied in the clinical settings for the treatment of severe bone turnovers and recently as imaging probes when conjugated with organic fluorophores. Herein, we introduce a bone seeking luminescent probe that shows high binding affinity towards bone minerals based on monophosphonated carbon dots (CDs). The spheroidal CDs tethered with PEG monophosphates are synthesized in one pot hydrothermal method and are physico-chemically characterized where the retention of phosphonates is confirmed by 13P NMR and XPS. Interestingly, the high abundance of multiple monodentate phosphonates exhibited strong binding to hydroxyapatite, the main bone mineral constituent. The remarkable opto-physical properties of monophosphonated-CDs were confirmed in an ex vivo model of bovine cortical bone where the imaging feasibility of microcracks as the calcium rich regions were demonstrated. Importantly, the in vivo studies specified the docking of monophosphonated-CDs on tibia. The biodigestible nature and cyto-compatibility of the probe presented here can obviate the demand for a secondary fluorophore while offering nanoscale strategy for bone targeting and can eventually be employed for potential bone therapy in the future.