A. Dommann, N.I. Anaraki, A. Sadeghpour, P. Wick, A. Neels
Empa, Swiss Federal Laboratories for Materials Sci-ence and Technology,
Keywords: colloidal stability of nanoparticles, dynamics in particle system synthesis, SAXS, WAXS
Summary:X-ray analytical methods are used to the study the dynamics in particle system synthesis and their early event dynamics in biological environments. X-ray based analytical methods are applied such as small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) including Pair Distribution Function (PDF) analysis. Nanomedical applications bring particles in direct contact with body fluids as contrast agents, vaccination or drug delivery vehicles. The colloidal stability of nanoparticles in biological media is a crucial issue in biomedical appli-cations since minor changes in the particle stability or agglomeration state could influence their behavior and cause some undesired consequences. An experimental method for in-situ quantitative observation of nanoparticles agglomeration in biological media flow would provide detailed understanding about the influence of effective parameters at nano-bio interfaces. In addition, the agglomeration kinetics of nanoparticles in different environments are not con-cretely determined yet. Here we study an in-situ method based on small angle X-ray scatter-ing (SAXS) and microfluidics to explore nano-particles agglomeration in different biological medias flow. We could measure the agglomeration rate constant and the mean agglomeration number of nanoparticles precisely. This method enables us to study the influence of various buffer systems, ion strength, pH, temperature, and also competing biomolecules such as pro-teins on nanoparticles agglomeration. Furthermore, these results are compared with the data obtained by dynamic light scattering (DLS) demonstrating a good agreement.