1 research outputs found
Luminescence Enhanced Eu<sup>3+</sup>/Gd<sup>3+</sup> Co-Doped Hydroxyapatite Nanocrystals as Imaging Agents In Vitro and In Vivo
Biocompatible, biodegradable,
and luminescent nano material can be used as an alternative bioimaging
agent for early cancer diagnosis, which is crucial to achieve successful
treatment. Hydroxyapatite (HAP) nanocyrstals have good biocompatibility
and biodegradability, and can be used as an excellent host for luminescent
rare earth elements. In this study, based on the energy transfer from
Gd<sup>3+</sup> to Eu<sup>3+</sup>, the luminescence enhanced imaging
agent of Eu/Gd codoping HAP (HAP:Eu/Gd) nanocrystals are obtained
via coprecipitation with plate-like shape and no change in crystal
phase composition. The luminescence can be much elevated (up to about
120%) with a nonlinear increase versus Gd doping content, which is
due to the energy transfer (<sup>6</sup>P<sub>J</sub> of Gd<sup>3+</sup> → <sup>5</sup>H<sub>J</sub> of Eu<sup>3+</sup>) under 273
nm and the possible combination effect of the cooperative upconversion
and the successive energy transfer under 394 nm, respectively. Results
demonstrate that the biocompatible HAP:Eu/Gd nanocrystals can successfully
perform cell labeling and in vivo imaging. The intracellular HAP:Eu/Gd
nanocrystals display good biodegradability with a cumulative degradation
of about 65% after 72 h. This biocompatible, biodegradable, and luminescence
enhanced HAP:Eu/Gd nanocrystal has the potential to act as a fluorescent
imaging agent in vitro and in vivo