Biotronics: Radiofrequency detection and control of cellular physiological process
Abstract
The objective of this project is to demonstrate noninvasive multi-frequency (MF) measurement of single cells, obtain cell membrane potential (MP), and detect molecular polarization and ion transport. Radiofrequency (RF) microfluidic devices will be designed and built for simultaneous electrical stimulation and bioelectricity probing. Interferometry based RF techniques will be developed for MF measurement from 0.1 to 8 GHz. Saccharomyces cerevisiae yeast and E. coli K12 wild type cells will be used in the efforts. The obtained cell MP will be compared with published data and results from fluorescent MP indicators. A second objective is to design and build ionic diodes that are based on nanofluidic channels and conduct preliminary investigation of ion transport (e.g. K and Cl ions) through the diodes under modulated electrical fields at different frequencies. The electrochemical nature of cells and their microenvironments couples cell physiology with bioelectricity, such as membrane potential (MP) and ion motive force (IMF). Studies of diverse cellular systems have shown that MP levels are linked to different cell states, bioelectrical signals are at the heart of cell communication, and intrinsic bioelectrical processes enable electrical control of cellular physiological processes. Various techniques have been developed to probe bioelectricity, including MP measurements, for which dielectric spectroscopy (DS) (at frequencies below 10 MHz) and label-free optical imaging are noninvasive. The results imply GHz measurements, which are at the higher end of radio frequency (RF) spectrum (3 kHz -300 GHz), are promising for bioelectricity probing. Furthermore, RF measurement is intrinsically noninvasive with potentially high resolution to address existing or new bioelectricity measurement needs. Recent results on RF flow cytometry for single cell detection and identification as well as DS measurement of E. coli and mitochondria MPs show the promise of RF MP probing at single cell or subcellular resolution without cell fixation. Furthermore, RF techniques are promising to monitor ion transport in cells and examine frequency selectivity or signal-modulation effects in electrical stimulation. The project is expected to develop a novel GHz system for MF measurement of single suspended cells, obtain measured GHz MF permittivity of yeast and E. coli cells, extract cell MP and ion transport information from GHz measurements. Additionally, preliminary results of frequency- and modulation-dependent ionic diode properties are anticipated from nanochannel-based ionic diodes. These results fill knowledge gaps, including GHz MF properties of single cells, GHz measurement methods for single cell MP and charge transport probing, and frequency selectivity and field demodulation effects of ionic diodes. The results also fill technology gaps, i.e. RF microfluidic devices and techniques to noninvasively characterize the bioelectricity of single cells in suspension. The obtained knowledge and technology will enable bioelectricity development at single cell level and help understand potential RF health risks for military personnel who are at close proximity to strong non-ionizing RF radiations. The results also help identify approaches to control and exploit RF bio effects.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 25, 2021
- Source ID
- W911NF2110145
Entities
People
- Pingshan Wang
Organizations
- Army Contracting Command
- Clemson University
- United States Army