Nd³⁺ sensitized core-shell-shell nanocomposites loaded with IR806 dye for photothermal therapy and up-conversion luminescence imaging by a single wavelength NIR light irradiation

Abstract

To perform photothermal therapy (PTT) and luminescence imaging by a single wavelength NIR light irradiation, we have designed and prepared a novel nanocomposite incorporating the IR806 photothermal sensitizers (PTS) into the core-shell-shell NaYF4:Yb,Er@ NaYF4:Yb@NaYF4:Yb,Nd up-conversion nanoparticles (UCNPs). Irradiation with the 793 nm near-infrared (NIR) laser, the Nd3+ ions in the UCNPs were sensitized to up-convert energy via Yb3+ to the Er3+ ions to emit visible light at 540 nm and 654 nm, as well as to down-convert energy to the Yb3+ ions to emit NIR light at 980 nm. For luminescence imaging, the 793 nm NIR radiation is more suitable to use for deeper-tissue penetration and to reduce overheating problem due to water absorption as compared to 980 nm radiation. Additionally, the same 793 nm NIR radiation could also excite the IR806 dye for effective PTT. Surface modifications of the UCNPs with mesoporous silica (mSiO2) and polyallylamine (PAH) allow stable loading of IR806 dye and further derivatization with polyethylene glycol-folic acid (PEG-FA) for tumor targeting. Preliminary in vitro studies demonstrated that the final UCNP@mSiO2/IR806@PAH-PEG-FA nanocomposites (UCNC-FAs) could be uptaken by the MDA-MB-231 cancer cells and were “dark” viable, and when irradiated with the 793 nm laser, the MDA-MB-231 cell viability was effectively reduced. This indicated that the UCNC-FAs nanocomposites could be potentially useful for targeted photothermal therapy and up-conversion luminescence imaging by a single wavelength NIR light irradiation.

Enhancing Förster Resonance Energy Transfer (FRET) Efficiency of Titania–Lanthanide Hybrid Upconversion Nanomaterials by Shortening the Donor–Acceptor Distance

“…The upconversion nanoparticles (UCNPs) were synthesized according to a literature reported method with minor modifications [ 35 ]. Core NaYF 4 :Nd,Yb NPs, a total of 1 mmol Ln-triacetate in the Y:Nd:Yb = 70:15:15 mol% ratio (for NaYF 4 :Yb,Tm NPs, in the Y:Yb:Tm = 89.5:10:0.5 mol% ratio) were added to a 10 mL oleic acid (OA) and 15 mL octadecene (ODE) solution.…”

“…In this study, we demonstrate that by doping the Tm 3+ emitters in the shell and the Nd 3+ and Yb 3+ sensitizers in the core and after the addition of a Yb 3+ shell and TiO 2 coating with polyallylamine hydrochloride (PAH)/polyethylene glycol folate (PEG-FA), the newly designed core/shell/shell hybrid UCNPs NaYF 4 :Nd,Yb@Yb@Yb,Tm@TiO 2 -PAH-PEG-FA (designated as Nd-Yb-Tm-TiO 2 -UCNCs) would achieve greater FRET efficiency to produce ROS for PDT as compared to that of the reference NaYF 4 :Yb,Tm@Yb@Nd,Yb@TiO 2 -PAH-PEG-FA (designated as Tm-Yb-Nd-TiO 2 -UCNCs), due primarily to shortened Tm 3+ -TiO 2 distance upon 793 nm NIR laser excitation ( Scheme 1 ). Note that the excitation at 793 nm on Nd 3+ doped UCNPs would give about 4 times greater luminescence intensity at 975 nm than that excitation at 808 nm, with lower power and increased safety [ 35 ]. To simplify the writing of these UCNPs formulas, the mol% values of the doping Ln 3+ ions are neglected unless if deemed necessary to clarify certain statements.…”

Injectable and NIR‐Responsive DNA–Inorganic Hybrid Hydrogels with Outstanding Photothermal Therapy

“…First, the injectable DNA‐inorganic hybrid hydrogel was prepared ( Figure ). In detail, the monodispersed NaYF 4 nanoparticles co‐doped with Yb 3+ and Er 3+ were prepared by a solvent thermal method [ 19 ] and then used as the core to form hybrids with NaYF 4 :Nd. The NaYF 4 :Yb,Er@NaYF 4 :Nd (UCNP) were further converted into hydrophilic UCNP‐PEI via a ligand exchange process using polyetherimide (PEI) as a surface coating agent to replace the original oleic acid ligands (Figure S1, Supporting Information).…”

Application of rare earth-doped nanoparticles in biological imaging and tumor treatment

“…[154][155][156][157][158] A versatile nanoparticle NaYF 4 :Yb,Er@ NaYF 4 : Yb@NaYF 4 :Yb,Nd for bioimaging and tumor treatment with NIR excitation (793 nm) and NIR emission (980 nm) was reported by Lin. 118 In order to obtain tumor targeting, mesoporous silica was coated on the surface of the NPs. Then, the positively charged PAH was absorbed to the NPs by electrostatic interaction.…”