Binary file ./template_functions.inc.php matches
Synthesis, aminosilane-folic acid functionalization and cytotoxicity of the upconversion nanoparticle Y 2 O 3 :Er 3+ , Yb 3+ for cancer cell detection (Trabajo presentado en Innovation Match Mx 2016) - RIIIT
Synthesis, aminosilane-folic acid functionalization and cytotoxicity of the upconversion nanoparticle Y 2 O 3 :Er 3+ , Yb 3+ for cancer cell detection (Trabajo presentado en Innovation Match Mx 2016)
Upconversion nanoparticles (UCN) have gained interest because they can absorb near infrared
radiation (NIR) and upconvert it into to higher energy light, such as the visible range, through the
sequential absorption of multiple photons or energy transfer. The UCN Y
2
O
3
co-doped with Yb
and Er
3+
Revista Internacional de Investigación e Innovación
Tecnológica
was synthesized by sol-gel method. These UCN find application in bioimaging, as
biolabels, to diagnose and visualize cancer cells, after coating and functionalization with ligands
that bind to receptors on the surface of the cell. The UCN were coated with a silica shell using
Stöber method and functionalized with aminosilane (APTES/TEOS) to enable folic acid
conjugation. After the folic acid conjugation, the cytotoxicity of UCN was tested on human
cervix carcinoma cells (HeLa) with a colorimetric assay based on the reduction of the MTT
reagent (methy-134 thiazolyltetrazolium). Different concentrations of bare and functionalized
UCN between 0.001 µg/mL to 1 µg/mL were used. The MTT assays show that some
concentrations of bare UCN of Y
2
Página principal: www.riiit.com.mx
O
3
: Er
3+
, Yb
3+
(1%, 1% mol) were cytotoxic for cervical
3+ adenocarcinoma cells (HeLa); however the functionalized UCN were not cytotoxic. The bare and
functionalized UCN were analyzed by transmission electron microscopy (TEM), Fourier
transform infrared spectroscopy (FTIR) and luminescence measurements. The results reveal that
functionalized UNC have a particle size of 70 nm (±10 nm) with a good luminescence spectrum
in comparison with the bare UCN. Finally, imaging studies were performed by epifluorescence
confocal microscopy; these revealed that UCN functionalized with folic acid were internalized by
HeLa cells. The fluorescence signal of folic acid-UCN was localized into the cell cytoplasm,
confirming with this their efficiency to be used as biolabels.
Keywords: aminosilane-folic acid functionalization, nanoparticles, sol-gel, upconversion luminescence, biolabels.
;)
