BMEG Seminar Series

Hannah Zierden, PhD

Department of Chemical and Biomolecular Engineering

University of Maryland

Seminar: Engineering Bacterial Extracellular Vesicles as Next-Generation Therapeutics for Women's Reproductive Health

The composition of the vaginal microenvironment has significant implications for gynecologic and obstetric outcomes. Where a Lactobacillus-dominated microenvironment is typically considered optimal, a polymicrobial environment is associated with increased risk for female reproductive diseases. Recent work has examined bacterial extracellular vesicles (bEVs) as an important mode of microbe-host communication in the female reproductive tract, with bEVs exhibiting unique species-and strain-level functions that may influence women’s health outcomes. We hypothesize that the physical properties of bacterial extracellular vesicles enable their mobility through cervicovaginal mucus and permit interactions with upper female reproductive tract tissues. As the first line of defense against bacteria and pathogens, cervicovaginal mucus protects against infection in the female reproductive tract through steric, hydrophobic, and electrostatic interactions with foreign pathogens. We demonstrate that the barrier properties of mucus prohibit the diffusion of whole bacteria through mucus, but that bEVs from common vaginal microbes diffuse more freely. Leveraging these endogenous barrier-crossing abilities of bEVs, we engineer bEVs as drug delivery carriers to deliver therapeutic proteins to the female reproductive tract. Our work demonstrates the ability of bEVs to mediate female reproductive diseases and highlights their potential as therapeutic modalities for treating dysbiosis and dysbiosis-associated diseases in the female reproductive tract.

Dr. Hannah Zierden joined the Department of Chemical and Biomolecular Engineering at the University of Maryland in 2022. Prior to joining UMD, Dr. Zierden earned her Ph.D. in Chemical Engineering from Johns Hopkins University in 2020 and completed postdoctoral research at the University of Maryland School of Medicine. Now, her research group works at the interface of biology and engineering to develop next-generation therapeutics to support gynecologic and obstetric health throughout the lifespan. With rational drug delivery at the core of their work, the Zierden Lab is particularly interested in how extracellular vesicles from both bacteria and mammalian cells facilitate disease, and how they can be leveraged as a novel drug delivery platform. Her group builds model systems to understand complex interactions between the host environment, the local microbiome, and novel mucosal delivery systems to support translationally relevant delivery science. Dr. Zierden leads a diverse team that has published work in high-impact journals and has earned several awards at the local, state, and national levels. She was the recipient of an NSF Graduate Research Fellowship, the MIT Rising Stars in Chemical Engineering Award, the Maryland Academy of Sciences Outstanding Young Engineer Award, an NIH K12 Clinical Research Award, an NSF CAREER Award, and an NIH Maximizing Investigators' Research Award.