Multifunctional calcium phosphate nano-contrast agent for combined nuclear, magnetic and near-infrared in vivo imaging

Manganese doped nano-bioactive glass for magnetic resonance imaging

“…We earlier reported Gd 3+ doped hydroxyapatite (HAp) nanoparticles for multimodal in vivo imaging [6,7,8], however in the present study, we have replaced HAp with BG considering its superior bone regeneration and resorption capabilities [9]. Further, toxicity concerns over the use of Gd 3+ motivated us to investigate manganese as an alternative paramagnetic element for doping BG [10][11][12].…”

“…pH was an important parameter to control the size of the nanoparticles. Addition of NH 4 OH reduced the gelation time of the reaction and maintained the pH at ~ 9 to obtain spherical nanoparticles [7]. Fig.1.…”

Calcium Phosphate Nanocoatings and Nanocomposites, Part I: Recent Developments and Advancements in Tissue Engineering and Bioimaging

“…In addition, it has also been suggested that lanthanide ions including europium (Eu 3+ ) and gadolinium (Gd 3+ ) are known functional mimics of calcium ions [51,56]. Consequently, researchers have begun to incorporate these rare earth elements into calcium phosphate nanoparticles and examine their potential uses in imaging applications [49][50][51][52]. Fluorescent capability of calcium phosphate nanoparticles doped with a small amount of europium was investigated by Mondejar et al [49].…”

“…The addition of luminescent or fluorescent capabilities to a calcium phosphate nanomaterial drug delivery system will further enhance their in vivo functionality. For this reason, investigations have begun to examine the possibility of conjugating QDs with calcium phosphate nanoparticles and nanowhiskers in addition to doping it with elements such as lanthanide and cyanine dyes such as indocyanine green in an effort to improve biocompatibility and to achieve elimination of cytotoxicity within a physiological environment [46][47][48][49][50][51][52][53][54]. Although most work is carried out on nanoparticles, the same approach could be used in nanocoatings.…”

“…They also observed the dualdoped nanospheres exhibited a strong near-infrared emission under the excitation of a certain wavelength and the photoluminescent intensity can be adjusted by varying the Eu 3+ and Gd 3+ concentrations. Later, Ashokan et al [52] also examined the potential use and production of a multimodal contrast agent. They observed by doping the calcium phosphate nanocrystals with Eu 3+ resulted in bright near-infrared fluorescence and codoping with Gd 3+ resulted in an enhancement in paramagnetic longitudinal relaxivity suitable for T1 weighted MRI together with approximately 80% x-ray attenuation suitable for x-ray contrast imaging.…”