Title: Interfacial properties of therapeutic proteins at the air-liquid interface and how they lead to aggregation

Over the past decade, the pharmaceutical industry has seen a vast increase in the development of novel antibody-based therapeutics. However, ensuring long term stability of biologics poses a significant challenge in drug development, as they are susceptible to protein degradation caused by thermal, chemical, and/or mechanical stresses, leading to the formation of subvisible particles that can adversely impact both the safety and efficacy of the drug product. It is also now recognized that due to a protein’s amphiphilic nature and tendency for interfacial adsorption, interfacial stresses encountered throughout bioprocessing and storage can lead to protein instability and protein particle formation, however the mechanisms governing interface-induced particle formation is still fundamentally lacking as these stresses are often coupled with other environmental stresses. The objective of this dissertation is to develop predictive tools to study and increase the understanding of the mechanisms leading to protein-protein interactions and their propensity to aggregate at the air-liquid interface at relevant pharmaceutical manufacturing and formulation conditions. This project will determine (1) how the interfacial properties of different monoclonal antibodies (mAbs) from protein adsorption, unfolding, and intermolecular interactions correlate to particle characterization in the bulk solution and at the air-liquid interface in response to isolated and combined environmental stresses (temperature, pH, hydrodynamic shear, interfacial dilatational stress) and (2) how differences in protein-based modalities, a mAb vs a Fusion protein, impact the formation of the protein film at the air-liquid interface over time and how this film responds to interfacial dilatational stress.