Aggregation of therapeutic monoclonal antibodies by bubbling induced air/liquid interfacial agitation

About author : Shravan Sreenivasan is currently working as a Ph.D Research Scholar with Prof. Anurag S. Rathore at Bioprocessing & Bio-Separations Laboratory, Department of Chemical Engineering at the Indian Institute of Technology Delhi. As part of the Ph.D, he is working on degradation of therapeutic proteins. Before joining IIT Delhi, he had worked at Curateq Biologics (Aurobindo Pharma), Hyderabad. He has done his M.Tech in Bioprocess Technology from Institute of Chemical Technology, Mumbai and B.Tech in Biochemical Engineering from University of Kerala.

Interview Questions

How would you explain your research outcomes to the non-scientific community?

Therapeutic proteins such as monoclonal antibodies have been used in the treatment of various diseases. Since the final drug product is a protein, there is a significant risk associated with the stability of these drug molecules. The issues associated with stability of these bio-molecules, such as aggregation, could affect the biological activity as well as be the reason for it’s toxicity. Aggregates occur when products are exposed to different stress conditions, among which the air/liquid interfaces occur during various stages of manufacturing, transport, handling and usage. The degradation of therapeutic monoclonal antibodies (mAb) due to interfacial agitation through air bubbling was investigated, where the samples containing mAb were subjected to rapid bubbling by using a peristaltic pump and the aggregates were monitored at regular intervals up to 4 hours. It was found that sub-visible and visible aggregates were formed that exhibited altered secondary structure and higher hydrophobicity with a reduction in activity.

How do these findings contribute to your research area?

The finding showed that the presence of air bubbles resulted in rapid degradation of therapeutic protein. Further, our strategy of generation of aggregates was effective, simple, reproducible, and cheap, and hence it could be an efficient way to generate aggregates for purposes such as mechanistic studies of protein aggregation, screening of novel excipients and protein formulation development. The bubbling set-up allowed screening of the influence of several factors, such as temperature, protein concentration, sample volume, intensity of agitation and presence of silicone oil as well as formulation excipients and pH, on the sensitivity of proteins to air/liquid interfacial agitation stress.

What was the exciting moment during your research?

The most exciting moment during the research was when it was observed that the air-bubbling induced agitation resulted in aggregation in less than half an hour. Further, the analytical and functional characterization of aggregates were equally exciting. The potential prospect that every possible stress factor should not be overlooked and should be deeply investigated in terms of its effect, structural and functional change on the protein along with the mechanism of degradation was an insightful finding.

What do you hope to do next?

As of now, I have started the work to estimate the immunogenic impact of aggregate generated by air/liquid interfacial agitation. Further, we are planning to evaluate the aggregation profile of these aggregates when they are spiked into biological fluids such as serum and vitreous humor.

Where do you seek scientific inspiration from?

I have been lucky to be mentored by amazing insightful mentors at various stages of my life. They have inspired me to better myself. My mentor during the master’s degree introduced me to research and taught me to push my boundaries of understanding and critical thinking. My Ph.D guide, Prof. Anurag Rathore has been instrumental in shaping my thought process, smart decision making, and on enabling me to purse new skills and mastering them, which I used to underestimate myself at one stage.

Reference

Sreenivasan, S., Jiskoot, W. and Rathore, A.S., 2021. Rapid aggregation of therapeutic monoclonal antibodies by bubbling induced air/liquid interfacial and agitation stress at different conditions. European Journal of Pharmaceutics and Biopharmaceutics168, pp.97-109.

Edited by: Dolly Singh