Interactions at an air-water interface can accelerate aggregation of antibody therapeutics, particularly under stresses encountered during manufacture, transportation, and administration of the antibodies. A better understanding of interfacially mediated aggregation assists in the design of more robust formulations to limit the formation of potentially immunogenic aggregates. A panel of monoclonal antibody therapeutics, exhibiting a range of aggregation propensities at an air-water interface, was characterized by multiple surface-sensitive techniques to measure the intermolecular interactions, concentration, hydrophobicity, and mechanical properties of the interfacial antibody films. The antibodies with the highest interfacial aggregation propensity exhibited more than a five-fold faster initial rate of surface pressure increase and rapidly formed hydrophobic films upon adsorption, which indicated these molecules were susceptible to interfacially induced protein unfolding. Strong, essentially irreversible protein-protein interactions, likely dominated by hydrophobic interactions, resulted in high levels of aggregation for these antibodies. In contrast, the antibodies with a low propensity to aggregate at the interface required many minutes of interfacial exposure to form hydrophobic films and did not develop strong, irreversible interactions. Overall, characterization of the interfacial properties of the antibodies allowed us to predict their extent of interfacially mediated aggregation. We also demonstrated a multistep aggregation mechanism at the air-water interface, where adsorption is a necessary but not sufficient condition for aggregation.

Predicting and understanding aggregation of antibody therapeutics at air-water interfaces

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.