Fig 1.
Synthesis of chemical intermediates for enhanced biocompatibility and tracking of nanoparticles in vivo.
Synthetic schemes to yield (a) alkNHS, (b) azSil and (c) azFl.
Fig 2.
Generation and characterization of radioluminescent particles.
A) Schematic of the development of Y2(SiO4)O:Ce using a core-shell method. B) Relaxation of cerium from it higher energy 5d state to its respective ground state of 2F7/2 and 2F5/2 in the Ce 1 site. C) Scanning electron micrograph of Y2(SiO4)O:Ce nanoparticles synthesized by the Stöber process. D) Photoluminescence and radioluminescence of nano core-shell particulates irradiated by 360 nm and a broadband 40 KeV tungsten x-ray source, respectively. E) Photoluminescence spectra of sub-100 nm Y2(SiO4)O/BSA/fluorescein nanoparticles in 1x PBS. A 100 μL sample of a 31.4 mg/ml dispersion was placed in 2.90 ml 1x PBS. The normal fluorescein peak at ca. 525 nm is present when the excitation wavelength is 425 nm (red) or 460 nm (blue). Also presented is the system excited at 357 nm (black) to show that the Y2(SiO4)O component is present.
Fig 3.
Detection of radioluminescent particles in mouse motor cortex.
A) Tile-scanned merge of RLP-injected mouse brain at 40x zoom DAPI (blue), RLPs (green), IBA-1 (red) and GFAP (white). M2 region highlighted with dotted line. B) Overlay of RLP injection sites determined by sectioning M2 region of n = 12 animals demonstrates highly reproducible localization of RLP delivery. C) RLP injection site inset demonstrates fluorescein signal near the injection site. D) IBA-1 expressing microglia and GFAP-expressing astrocytes are detectable by the injection site 24 hours post-injection. E) RLP and cellular markers together.
Fig 4.
Quantifying changes in radioluminescent particle signal over time.
A) mean background-normalized fluorescence intensity of the fluorescein (FITC) channel across the entire M2 region compared to the contralateral saline vehicle-injected side was significantly greater (p<0.05), whereas no differences were observed between 1mg/ml and 3mg/ml groups (p>0.05). B) Time course data showing control-normalized RLP-fluorescein (FITC) fluorescence intensity at 1mg/ml and 3mg/ml doses at each 24hr, 72hr and 9 days post-injection. Significantly greater fluorescence was observed in the 24hr group compared to the 72hr and 9 day timepoints (p>0.05). C) The volume of RLP spread and the area of necrosis for each 24hr, 72hr and 9 day time points in 1 and 3mg/ml treated animals.
Fig 5.
Quantifying immune cell presence adjacent to radioluminescent particle injections.
A) Representative image of IBA-1+ microglia and B) GFAP+ astrocytes near RLP injection site. C) Fluorescence intensity of IBA-1 and D) GFAP staining in vehicle (saline) versus RLP-injected M2 following injections of 1mg/ml and 3mg/ml in mice sacrificed 24 hours after injection. E) Total fluorescence intensity of IBA-1 and F) GFAP in RLP-injected M2 (normalized to vehicle-treated contralateral hemisphere) for animals receiving 1 and 3 mg/ml concentrations of RLPs 24 hours, 72 hours, and 9 days post-injection. (G) In vitro Alamar blue assay revealed no significant changes in cell viability of cultured neurons following RLP exposures at multiple timepoints compared to untreated controls (dashed line at “1”).