SMALL-ANGLE X-RAY SCATTERING AS A TOOL FOR CHARACTERIZING SILICA NANOPARTICLES IN NEAR-BIOLOGICAL MEDIA

Nanoparticles (NPs) designed for nanomedicine must navigate complex biological environments where factors like colloidal stability, surface interactions, and aggregation are profoundly influenced by the characteristics of surrounding fluids. Crucially, the surface properties of NPs, including charge and functional modification, play a pivotal role in determining their interactions, impacting their stability and bioavailability^[1]. This study leverages small-angle X-ray scattering (SAXS) to characterize silica nanoparticles (SiO₂) directly in near-biological fluids, without requiring pre-sample treatments, thereby preserving their native state. SAXS is a highly efficient and versatile technique for structural analysis, ideally suited for assessing nanomaterials under native, physiologically relevant conditions^[2]. This approach enables researchers to observe the true colloidal behavior of NPs, which is especially pertinent for the study of soft matter systems and nanomedicine applications. By fitting SAXS data to a sticky hard sphere model, we can derive detailed insights of tendencies of NPs across conditions relevant to oral and intravenous drug delivery. The findings underscore SAXS’s unique capability to provide a systematic, high-resolution analysis of NPs in biologically relevant settings.