Cytotoxicity of Gd 2O3:Ln 3+ Nanostructures and their Potential as Biomarkers

In this study erbium and ytterbium doped gadolinium oxide nanostructures were synthesized. To investigate the influence of morphology on the optical and biological properties of the obtained particles, different types of nanoparticles were prepared. First, Gd(OH) 3:Er 3+ ,Yb 3+ nanorods of aspect ratios of 5 and 12 were synthesized by hydrothermal method, which could be transformed into the oxide phase by post-thermal treatment. Enzymatic and alkaline precipitation methods were used to prepare nanoparticles of approx. 40 nm in diameter and larger particles with less homogeneous size distribution in the range from 100 nm to 1 μm, respectively. Spherical particles of 300 nm in diameter and with a homogeneous size distribution were obtained by homogeneous precipitation. Investigation of their optical properties, in particular upconversion emission and near-infrared emission, revealed the potential use of the obtained nanostructures for applications as biomarkers. In this context, morphology and size effects on the cytotoxicity of Ln 3+ -doped gadolinium oxide were investigated using B- cell hybridomas and macrophages. Concentrations of particles up to 500 μg/mL at an incubation period of 48 hrs were analyzed.