ChE Seminar Series: Tagbo H.R. Niepa, Ph.D.

Date(s) - 02/20/2024
9:00 am - 10:00 am

HPNP 1404


Title: Nanocultures: High-throughput platform for assessing microbial community dynamics in sessile drops

Tagbo H.R. Niepa, Ph.D.
Associate Professor
Chemical Engineering and Biomedical Engineering
Carnegie Mellon University

The need for assessment tools for microbial dynamics has necessitated the miniaturization of cell-culturing techniques and the design of microsystems that facilitate the interrogation of microorganisms in well-defined environments. The nanocultures are such an assessment tool: nanoliter-sized microcapsules generated using a flow-focusing microfluidic device to sequester and cultivate microbes in a high-throughput manner. Each nanoculture begins as a nanoliter droplet of cell suspension encapsulated by a polydimethylsiloxane (PDMS) membrane. By manipulating the chemistry of their polymeric shell, the nanocultures can achieve functionalities, such as selective permeability facilitating the transport of metabolites and other small molecules essential to cell growth and community dynamics. The nanocultures allow the diffusion of antibiotics, signaling molecules, and functional fluorescent probes to interrogate cell physiology and facilitate microbial interactions across the confining vessel. Alternatively, multiple species of microbes can be co-cultured within the nanocultures. Because of the chemical exchange occurring within and across the shell, the nanocultures can help investigate microbial pathophysiology. Here, we demonstrate this platform by exploring broad ranges of direct and indirect microbial dynamics. This versatile new tool has broad potential for addressing biological questions associated with drug resistance, chronic infections, antibiotic discovery, and microbiome dynamics relevant to complex microbial communities.

Dr. Niepa is an Associate Professor of Chemical Engineering and Biomedical Engineering at Carnegie Mellon University, Pittsburgh PA. He started his academic journey in Côte d’Ivoire after receiving an Associate Degree in Food Science and a research experience at the Pasteur Institute. He then moved to Germany to pursue his education in bioengineering at the University of Dortmund and transferred to Syracuse University. He received his B.Sc. in Bioengineering (2009) and Ph.D. in Chemical Engineering (2014) with honors from Syracuse University. His doctoral study of the Electrochemical Control of Bacterial Persister Cells under Profs. Dacheng Ren and Jeremy Gilbert focused on developing an electrochemical technology against drug-resistant and persistent bacteria, which was awarded two US patents. During his Ph.D. study, Dr. Niepa co-founded in 2011 Helios Innovative Technologies Inc. (now acquired by Leviant, Inc.), a medical device company that develops automated sterilization systems to fight bacterial cross-contamination. He held a Postdoctoral Fellowship for Academic Diversity at the University of Pennsylvania, working with Chemical Engineering Profs. Kathleen Stebe, Daeyeon Lee, Hyun Koo (Dentistry) and Mark Goulian (Biology) to develop new methods to study microbial dynamics in artificial microniches and thin films. In 2017, he joined the University of Pittsburgh as an assistant professor of Chemical and Petroleum Engineering. Since Fall 2023, he leads his microBiointerface Lab at CMU into multidisciplinary approaches to solve problems associated with microorganisms relevant to the environment, healthcare, and food industry. Dr. Niepa is the recipient of the 2022 NIH Director’s New Innovator, the 2022 NSF CAREER, and the 2019 NSF S-STEM Awards to promote diversity and excellence in engineering research and education.