Enhanced Insights into Macromolecular Interactions: High-Throughput B ₂₂ Mapping Using Static Light Scattering

Static light scattering (SLS) is a widely used technique for characterizing size, molecular weight, and interactions of macromolecules such as polymers and proteins. In pharmaceutical formulation design, protein–protein interactions (PPI) are commonly assessed by the second osmotic virial coefficient (B22) derived from SLS data. While conventional methods like the composition-gradient multi-angle light scattering (CG-MALS) yield highly accurate B22-values, they are limited by lengthy processing times and substantial material requirements. Within this work we developed a novel high-throughput method for rapid generation of experimental SLS data using automated liquid handling and plate-based SLS measurements. Validation of this method was performed through direct comparison with SLS data and B22-values obtained via CG-MALS. To demonstrate its applicability, B22 maps of PEG6000 and dextran in the presence of trehalose and l-arginine in phosphate buffer were generated. These maps reliably captured the influence of varying excipient concentrations on macromolecular interactions, except in cases with minimal B22 changes, as observed with dextran and l-arginine. However, for applications requiring extensive SLS data but do not require the highest level of sensitivity, the high-throughput method is especially well-suited. A potential future application could be its extension to biological systems, thereby supporting pharmaceutical formulation development.