Colloidal interactions between monoclonal antibodies in aqueous solutions.

Colloidal interactions between proteins determine the behavior and stability of globular proteins such as monoclonal antibodies (mAbs) against their propensity to cluster formation in solution. We study interactions between these proteins through their dilute solution behavior. Experiments to quantify intermolecular interactions were done using Dynamic and Static Light Scattering (DLS and SLS) in a high-throughput manner in parallel with zeta potential measurements with Laser Doppler Electrophoresis method (M3-PALS). This approach offers a rapid indirect determination of colloidal interactions through their measured second virial coefficient. Electrostatic part of the DLVO interaction was conveniently parameterized via the corresponding surface charge and/or surface potential, while the van der Waals interactions were parameterized via their Hamaker coefficient, both as functions of ionic strength and pH of the bathing solution. This parametrization of protein-protein interactions improves our understanding of mAb assembly and provides a means for its control by solution parameter variation. Additionally, our results also provide a consistency check and validation of applicability of the DLVO theory in mAbs solution assembly processes.