Simulation and Modeling Small-Angle X-ray Scattering of Polyelectrolyte Complex Micelles

Small-angle X-ray scattering (SAXS) utilizes a high-intensity X-ray source to provide multiscale structural information for nanoscale materials, which helps to quantify the physical properties and internal features of nanoparticles including polyelectrolyte complex micelles (PCMs). PCMs are core-shell nanoparticles that self-assemble by phase separation of neutral-cationic block copolymers with anionic polymers. PCMs feature a hydrated coacervate interior and neutral exterior which helps to condense and deliver therapeutic nucleic acids. PCM studies often use SAXS to evaluate form factors, but that requires time-intensive manual modeling. Previous work has shown the use of densely connected hidden layers to estimate physical parameters from scattering data of micelles. Still, these methods are unoptimized for the spatial nature of SAXS data. Thus, we combine analytical form factor equations and computational probability modeling to simulate the SAXS profiles of PCMs. Then we use these data to develop a 1-D convolutional neural network to predict the core radius and polydispersity of PCMs from SAXS data. Initial steps developed size modeling guidelines with plans to model morphological changes and improve the correlation between experimental and simulated data.