NIR photo-driven upconversion in NaYF4:Yb,Er/PLGA particles for in vitro bioimaging of cancer cells

Abstract

Lanthanide-doped fluoride up-converting nanoparticles (UCNPs) represent the new class of imaging contrast agents which hold great potential for overcoming existing problems associated with traditionally used dyes, proteins and quantum dots. In this study, a new kind of hybrid NaYF:Yb,Er/PLGA nanoparticles for efficient biolabeling were prepared through one-pot solvothermal synthesis route. Morphological and structural characteristics of the as-designed particles were obtained using X-ray powder diffraction (XRPD), scanning and transmission electron microscopy (SEM/TEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopy, while their cytotoxicity as well as up-conversion (UC) labeling capability were tested in vitro toward human gingival cells (HGC) and oral squamous cell carcinoma (OSCC). The results revealed coexistence of the cubic (Fm-3m) and hexagonal (P6/m) phase in spherical and irregularly shaped nanoparticles, respectively. PLGA [Poly(lactic-co-glycolic acid)] ligands attached at the surface of UCNPs particles provide their enhanced cellular uptake and enable high-quality cells imaging through a near-infrared (NIR) laser scanning microscopy (λ = 980 nm). Moreover, the fact that NaYF4:Yb,Er/PLGA UCNPs show low cytotoxicity against HGC over the whole concentration range (10-50 μg/mL) while a dose dependent viability of OSCC is obtained indicates that these might be a promising candidates for targeted cancer cell therapy.

Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies

“…The diffraction peaks of reverse micro-emulsion synthesized UCNP1 and UCNP2 are matches well the JCPDS:16-0334 of hexagonal β-NaYF 4 . The hexagonal phase UCNP1 and UCNP2 are crystalline with the space group of p63/m [ 5 ]. The diffraction peaks of the UCNP1-PLGA-nanocur and UCNP2-PLGA-nanocur broaden with a decrement in their peak intensity compared to UCNP1 and UCNP2, and it can be identified at 29 and 30° corresponding to the (110) and (101) planes.…”

“…It affirms that the nanocurcumin efficiently loaded with UCNPs via PLGA ligands attached on the surface of the nanocarrier. The PLGA functionalization with carboxylic groups could improve the binding affinity between the nanocurcumin drug and the UCNP nanocarrier, which will be useful for drug delivery applications [5]. NaYF 4 :Yb,Er (UCNP) exhibits a strong absorption peak around 550 cm −1 and small absorption peak at 605 cm −1 which corresponds to stretching vibrations of metal fluorides.…”

“…These properties make UCNPs an excellent platform for biovisualization. However, UCNPs could additionally be loaded with antitumor drugs to obtain a theranostics platform with both visualization and therapeutic properties [ 5 ].…”

Cytotoxic effects of different aromatic plants essential oils on oral squamous cell carcinoma: An in vitro study

“…Negative (no cells), solvent (0,02% DMSO), and positive controls (cells in complete growth medium) were also included. After 24h of incubation, cells were washed with 100µl phosphate buffered saline (PBS) and 100µl of MTT solution was added and incubated for 3 hours 24 . Finally, after the dissolution in isopropanol the absorbance at 560 nm was measured using a microplate reader (RT-2100C, China) and the obtained values were presented as percentages of viability.…”

Effects of different polymers and solvents on crystallization of the $$\hbox {NaYF}_{4}$$:Yb/Er phase

“…Furthermore, 10 nm PEGylated UCNPs, prepared solvothermally under the cooperative influence of two ligands (polyethylene glycol bis(carboxymethyl)ether and oleic acid) demonstrated excellent biodistribution in small animals [23], while PEI/FAfunctionalized UC NPs (FA-folic acid) were successfully used for the targeted release of doxycycline [24]. Recently, we have also shown that chitosan (CS) and poly(lactide-coglycolide) could also be used during hydrothermal synthesis of NaYF 4 :Yb/Er nanoparticles, as the source for amino and carboxyl ligands, respectively, for providing low cytotoxicity of UCNP and excellent cell internalization capability towards oral squamous cell carcinoma and normal human gingival cells [25,26]. Besides surface chemistry, monodispersibility and size control of biocompatible UCNPs represent another challenge which can be overcome by the use of polymers.…”