Transepithelial Electrical Impedance Increase Following Porous Substrate Electroporation Enables Label-Free Delivery

Authors

Justin R. Brooks, University of Nebraska - LincolnFollow
Tyler C. Heiman, University of Nebraska-Lincoln
Sawyer R. Lorenzen, University of Nebraska-LincolnFollow
Ikhlaas Mungloo, University of Nebraska-Lincoln
Siamak Mirfendereski, University of Nebraska-LincolnFollow
Jae Sung Park, University of Nebraska-LincolnFollow
Ruiguo Yang, University of Nebraska-LincolnFollow

Date of this Version

10-20-2023

Citation

doi: https://doi.org/10.1101/2023.10.17.562630

Comments

Used by permission.

Abstract

Porous substrate electroporation (PSEP) is a promising new method for delivering molecules such as proteins and nucleic acids into cells for biomedical research. Although many applications have been demonstrated, fundamentals of the PSEP delivery process are not yet well understood, partly because most PSEP studies rely solely on fluorescent imaging for evaluating delivery and quantifying successful outcomes. Although effective, only utilizing imaging alone limits our understanding of the intermediate processes leading to intracellular delivery. Since PSEP is an electrical process, electrical impedance measurements are a natural addition to fluorescent imaging for PSEP characterization. In this study, we developed an integrated device capable of simultaneously measuring impedance and performing PSEP and we monitored changes in transepithelial electrical impedance (TEEI), an electrical characteristic of cell monolayers that has not yet been leveraged for understanding PSEP. Our TEEI measurements show PSEP behaves differently from other electroporation methods following membrane permeabilization, with a significant increase in TEEI during high-efficiency, low-death delivery. We demonstrated how this post-electroporation response is influenced by cell culture conditions and electrical waveform parameters. More importantly, we were able to show label-free delivery of PSEP by leveraging TEEI monitoring. Specifically, correlating features of the post-electroporation response with cell viability and delivery efficiency allows prediction of delivery outcomes without fluorescent cargo, imaging, or image processing. This label-free delivery allows for improved temporal resolution of transient processes that occur following PSEP, which we expect will aid PSEP optimization for new cell types and cargos.