Incorporation of Computed Tomography and Magnetic Resonance Imaging Function into NaYF₄:Yb/Tm Upconversion Nanoparticles for in Vivo Trimodal Bioimaging

Abstract

Rational design and fabrication of multimodal imaging nanoprobes are of great significance for in vivo imaging. Here we report the fabrication of a multishell structured NaYF4:Yb/Tm@NaLuF4@NaYF4@NaGdF4 nanoprobe via a seed-mediated epitaxial growth strategy for upconversion luminescence (UCL), X-ray computed tomography (CT), and magnetic resonance (MR) trimodal imaging. Hexagonal phase NaYF4:Yb/Tm is used as the core to provide UCL, while the shell of NaLuF4 is epitaxially grown on the core not only to provide an optically inert layer for enhancing the UCL but also to serve as a contrast agent for CT. The outermost NaGdF4 shell is fabricated as a thin layer to give the high longitudinal relaxivity (r1) desired for MR imaging. The transition shell layer of NaYF4 not only provides an interface to facilitate the formation of NaGdF4 shell but also inhibits the energy transfer from inner upconversion activator to surface paramagnetic Gd(3+) ions. The fabricated multishell structured nanoprobe shows intense near-infrared UCL, high r1 value of 3.76 mM(-1) s(-1), and in vitro CT contrast effect. The multishell structured nanoprobe offers great potential for in vivo UCL/CT/MR trimodal imaging. Further covalent bonding of folic acid makes the multishell structured nanoprobe promising for in vivo targeted UCL imaging of tumor-bearing mice.

Upconverting Nanoparticles Prompt Remote Near‐Infrared Photoactivation of Ru(II)–Arene Complexes

“…[20] Conversely,B onnet and co-workersa lso reported ap romising system for activation at l = 630 nm of am odel Ru-polypyridyl complexb yu sing triplet-tripleta nnihilation upconversion. [23] The unique optical (upconversion emission) and chemical (e.g.,G d 3 + and 18 F À ions on the surface) features of UCNPs are also exploitedf or multimodali maging (i.e.,s ingle-photon emission computedt omography/positron emission tomography (SPECT/PET), [24,25] computed tomography (CT), [26] magnetic resonance imaging (MRI), [27] optical, [28] and photoacustic), [29] as demonstrated by numerouss tudies in vivo, which have appeared in the last few years. These properties and the low toxicity of UCNPs [30] make hybrid nanomaterials based on UCNPs and metal complexes suitable for application in theranostics.…”

Multimodal Cancer Imaging Using Lanthanide-Based Upconversion Nanoparticles

“…Absorption of water in the near-infrared light region and schematic design of Nd 3+ -sensitized upconversion process through core-shell structural engineering: NaYF 4 :Yb/Er/Nd@NaYF 4 :Nd [94], NaYbF 4 :Nd@ Na(Yb,Gd)F 4 :Er@NaGdF 4 [95], NaGdF 4 :Yb/Er@NaGdF 4 :Nd/Yb [97], NaGdF 4 :Nd@NaYF 4 @NaGdF 4 :Nd/Yb/Er@ NaYF 4 [98], NaYF 4 : Yb/Er@NaYF 4 :Yb@NaNdF 4 :Yb [99]. the magnetic shell, a series of multifunctional nanocomposites such as NaYbF 4 :Tm 3+ /NaGdF 4 , NaYF 4 : Yb/Tm@NaLuF 4 @NaYF 4 @NaGdF 4 , NaYbF 4 :Er 3+ @ NaGdF 4 were prepared [71,105,106], which showed excellent multimodal imaging capacities. Although core-shell approach mentioned above can integrate individual function into one nanosystem, their multistep synthesis procedures are usually complicated and time consuming.…”

Synthesis of Small Ce3+-Er3+-Yb3+ Tri-Doped BaLuF5 Active-Core-Active-Shell-Active-Shell Nanoparticles with Strong Down Conversion Luminescence at 1.5 μm

“…Recently, trivalent rare-earth (RE 3+ ) ions doped fluoride nanoparticles (NPs) have been applied widely in many fields of high technology, such as bioimaging, drug delivery, photodynamic therapy, solar cells [1,2,3,4,5,6,7,8,9,10,11,12], etc. In particular, Er 3+ -doped fluoride NPs have been applied in waveguide amplifiers [13,14,15,16] since intra-4f-shell transitions of Er 3+ ions not only cause visible light emissions but also send an emission at 1.5 μm (the 4 I 13/2 → 4 I 15/2 transition of Er 3+ ions), which is located in low loss windows of optical communication networks.…”