Nanotoxicology and Nanosafety

Fundamental equipment for characterization of nanoparticles, nanomaterials, polymers and biomolecules dispersed in a liquid medium such as water, organic solvents, buffers and biological media in general. The study of the toxicity of any type of nanostructure requires an understanding of its interaction with the culture medium and biological fluids (characterization of size, electrical charge, biocoronas formation and aggregation/agglomeration phenomena). Furthermore, for the execution of many protocols and standardized tests (toxicity, safety and regulation) it requires the characterization of nanomaterial dispersions using Dynamic Light Scattering (DLS) and Electrophoretic Light Scattering (ELS) techniques. The Zetasizer Ultra equipment has a new technology to measure particle size in scatterings through fast multi-angle dynamic light scattering (MADLS®) measurements, which significantly increases the precision and accuracy of size measurements. In addition, Zetasizer Ultra features a method for determining the concentration/number of particles in dispersion.

Multi-Angle Dynamic Light Scattering (MADLS) and Electrophoretic Light Scattering (ELS) – (Zetasizer Ultra, Malvern, UK).
– Angles: 173°, 13° and 90°.
– Diameters achieved: 0.3 nm to 15 μm.
– Minimum concentration: 0.1 mg/ml or 15 kDa (protein).
– Measurements of the zeta potential of particles between 3.8 nm to 100 μm.
– Particle concentration analysis: from 1×108 to 1×1012 particles/mL.
– Accessories: automatic titrator (MTP-3) and viscometer (SV-10).A703

Enhanced Darkfield Hyperspectral Microscopy (EDHM) is a system for the identification of nanoparticles after interaction with biological systems and diverse complex matrices. This equipment combines darkfield optical microscopy (VNIR 400-1000 nm) and fluorescence techniques for high-resolution spectral imaging (CytoViva® System). Through advanced analysis software, a spectral library with a nanometric resolution of the material under study is generated from its light scattering spectra. Once the spectral signature of the nanomaterial of interest is obtained, it is possible to identify it in different matrices, such as cells and biological tissues. This identification is based on the spectral identity of the nanomaterial (library), not having the need to use contrasts or fluorophores to mark the nanomaterial under study. In this way, it is possible to differentiate isolated nanoparticles from functionalized nanoparticles coated with biomolecules or in aggregates, once their spectral identity is altered. However, patterns and morphological changes in biological tissues can also be monitored using EDHM – CytoViva microscopy (CytoViva Inc., Auburn, USA);
• Dark-field optical microscope (Olympus, Model BX53) equipped with 10, 40, 63 and 100x objectives and fluorescence filters at the wavelengths of the fluorophores DAPI (blue), Texas Red (red) and FITC (green);
• Spectral camera ranging from 400 to 1000 nm (VNIR) and spectral resolution of 1.5 nm (with 30 μm aperture). Maximum spatial scan width of 896 µm at 10x magnification;
• Pixel size: 6.45 μm x 6.45 μm;
• Resolution: 1392 x 1040;
• Exposure time: from 5 μs to 60 sec;
• Image analysis software: Envi 4.8.

• Enhanced dark-field hyperspectral microscopy (EDHM) – CytoViva microscopy (CytoViva Inc., Auburn, USA);
• Dark-field optical microscope (Olympus, Model BX53) equipped with 10, 40, 63 and 100x objectives and fluorescence filters at the wavelengths of the fluorophores DAPI (blue), Texas Red (red) and FITC (green);
• Spectral camera ranging from 400 to 1000 nm (VNIR) and spectral resolution of 1.5 nm (with 30 μm aperture). Maximum spatial scan width of 896 µm at 10x magnification;
• Pixel size: 6.45 μm x 6.45 μm;
• Resolution: 1392 x 1040;
• Exposure time: from 5 μs to 60 sec;
• Image analysis software: Envi 4.8.