In-vitro visualization of primary tumor cells using up-conversion nanophosphors

Abstract

For such purpose, Ln-UCNPs should have specific morphological characteristics and efficient luminescence response. In this work, a biocompatible and water dispersible NaYF4:Yb,Er@PLGA nanoparticles synthesized using a one-step hydrothermal synthesis were tested as fluorescent bio-labels of primary cell cultures obtained after passage of head and neck squamous carcinoma cells (HNSCC). Structural, morphological and optical properties of particles were obtained using X-ray powder diffraction (XRPD), field emission scanning and transmission electron microscopy (FESEM/TEM), energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) and photoluminescence (PL) spectroscopy. The results revealed coexistence of the cubic (Fm-3m) and hexagonal (P63/m) phase in spherical and irregularly shaped nanoparticles, respectively. Moreover, preservation of the PLGA ligands at the particles surface facilitates their interactions with the cell membrane and provides permeation into cells. To asses a biological safety of their use, viability of human gingival fibroblasts (HFG) was additionally evaluated by a colorimetric MTT assay.