One-Step Synthesis of Biocompatible NaY0.65Gd0.15F4:Yb,Er Upconverting Nanoparticles for In Vitro Cell Imaging

There is a great technological interest in synthesis of lanthanide doped upconverting nanoparticles (UCNPs) with controlled crystal phase, morphology and intense luminescence properties suitable for biomedical use. A conventional approach for synthesis of such particles comprises decomposition of organometallic compounds in an oxygen-free environment, followed either with a ligand exchange, or biocompatible layer coating. Biocompatible NaY0.65Gd0.15F4:Yb,Er nanoparticles used in this study were synthesized through chitosan assisted one-pot hydrothermal synthesis and were characterized by X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) and photoluminescence measurement (PL). Due to the presence of the amino groups at their surface, excellent biocompatibility and notably low cytotoxicity against MRC-5 cells (line of normal human fibroblasts) and A549 cells (human lung cancer cells) were detected using MTT assay. Furthermore, upon 980 nm laser irradiation, particles were successfully used in vitro for labeling of both, MRC-5 and A549 cells

One-Step Synthesis of Biocompatible NaY0.65Gd0.15F4:Yb,Er Upconverting Nanoparticles for In Vitro Cell Imaging

There is a great technological interest in synthesis of lanthanide doped upconverting nanoparticles (UCNPs) with controlled crystal phase, morphology and intense luminescence properties suitable for biomedical use. A conventional approach for synthesis of such particles comprises decomposition of organometallic compounds in an oxygen-free environment, followed either with a ligand exchange, or biocompatible layer coating. Biocompatible NaY0.65Gd0.15F4:Yb,Er nanoparticles used in this study were synthesized through chitosan assisted one-pot hydrothermal synthesis and were characterized by X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) and photoluminescence measurement (PL). Due to the presence of the amino groups at their surface, excellent biocompatibility and notably low cytotoxicity against MRC-5 cells (line of normal human fibroblasts) and A549 cells (human lung cancer cells) were detected using MTT assay. Furthermore, upon 980 nm laser irradiation, particles were successfully used in vitro for labeling of both, MRC-5 and A549 cells

Temperature Sensing Properties of Biocompatible Yb/Er-Doped GdF3 and YF3 Mesocrystals

Y0.8−xGdxF3:Yb/Er mesocrystals with a biocompatible surface and diverse morphological characteristics were successfully synthesized using chitosan-assisted solvothermal processing. Their structural properties, studied using X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and energy dispersive X-ray analysis, were further correlated with the up-conversion emission (λexc = 976 nm) recorded in function of temperature. Based on the change in the visible green emissions originating from the thermally coupled 2H11/2 and 4S3/2 levels of Er3+, the corresponding LIR was acquired in the physiologically relevant range of temperatures (25–50 °C). The detected absolute sensitivity of about 0.0042 °C−1, along with the low cytotoxicity toward both normal human lung fibroblasts (MRC-5) and cancerous lung epithelial (A549) cells, indicate a potential for use in temperature sensing in biomedicine. Additionally, their enhanced internalization in cells, without suppression of cell viability, enabled in vitro labeling of cancer and healthy cells upon 976 nm laser irradiation

Selective in vitro labeling of cancer cells using NaGd0.8Yb0.17Er0.03F4 nanoparticles

Cancer represents one of the leading problems of today, with clinical detection oftentimes being difficult, currently based on imaging techniques, such as X-ray, computed tomography (CT) and magnetic resonance imaging (MRI). However, mortality rate is often reduced by early detection, therefore much focus has been directed towards developing methods for early detection of the disease. Recent research in the field of nanotechnology is focused on the use of nanoparticles, particularly Lanthanide-doped up-conversion nanoparticles (UCNPs), for the detection of cancer cells using near infrared (NIR) fluorescence microscopy. The reason for this is that in long-term tracking tests, nearinfrared (NIR) light, has lower phototoxicity and higher tissue penetration depth in living systems as compared with UV/VIS light. In this research, NaGd0.8Yb0.17Er0.03F4 UCNPs were prepared by solvothermal synthesis in the presence of chitosan, a ligand which enables UCNPs biocompatibility and the specific antibody conjugation. Morphological and structural characterization of synthetized UCNPs were performed based on X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PL). Results confirmed the presence of the cubic phase with a minor portion of hexagonal phase in nanoparticles. Synthesized nanoparticles were conjugated further with anti-human CD44 antibodies, labeled with fluorescein isothiocyanate (FITC), which signal is used for confirmation of nanoparticles positioning in cells. Such obtained conjugates were successfully used for selective in vitro biolabeling of oral squamous cell carcinoma cells