Ultrasmall, water dispersible, TWEEN80 modified Yb:Er:NaGd(WO4)2nanoparticles with record upconversion ratiometric thermal sensitivity and their internalization by mesenchymal stem cells.
This work presents the synthesis by coprecipitation of diamond shaped Yb:Er:NaGd(WO4)2crystalline nanoparticles (NPs) with diagonal dimensions in the 5-7 nm × 10-12 nm range which have been modified with TWEEN80 for their dispersion in water, and their interaction with mesenchymal stem cells (MSCs) proposed as cellular NP vehicles. These NPs belong to a large family of tetragonal Yb:Er:NaT(XO4)2(T = Y, La, Gd, Lu; X = Mo, W) compounds with green (2H11/2+4S3/2→4I15/2) Er-related upconversion (UC) efficiency comparable to that of Yb:Er:β-NaYF4reference compound, but with a ratiometric thermal sensitivity (S) 2.5-3.5 times larger than that of the fluoride. At the temperature range of interest for biomedical applications (∼293-317 K/20-44 °C) S = 108-118 × 10-4K-1for 20 at%Yb:5 at%Er:NaGd(WO4)2NPs, being the largest values so far reported using the2H11/2/4S3/2Er intensity ratiometric method. Cultured MSCs, incubated with these water NP emulsions, internalize and accumulate the NPs enclosed in endosomes/lysosomes. Incubations with up to 10 μg of NPs per ml of culture medium maintain cellular metabolism at 72 h. A thermal assisted excitation path is discussed as responsible for the UC behavior of Yb:Er:NaT(XO4)2compounds.
Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, c/Sor Juana Inés de la Cruz 3, E-28049 Madrid, Spain.
Concepción
C
Cascales
Carlos L
CL
Paíno
Eulalia
E
Bazán
Carlos
C
Zaldo
D011992:Endosomes / Q000378:metabolism; D005063:Europium / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D005682:Gadolinium / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D053758:Nanoparticles / Q000737:chemistry / Q000627:therapeutic use; D011136:Polysorbates / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D017973:Tungsten Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D015018:Ytterbium / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
D011136:Polysorbates; D017973:Tungsten Compounds; D005063:Europium; D005682:Gadolinium; D015018:Ytterbium