Mapping the Extracellular Relationship between Voltage and Biochemistry at the Cellular Level
Abstract
Regeneration and repair of tissue (wound healing) is a critical challenge in cases or trauma, surgery, acute illness and chronic disease. Clinical approaches to address wound healing are hampered by a poor understanding at the cellular and molecular level of the complex processes involved. A diverse group of cell types, including platelets, neutrophils, fibroblasts, keratinocytes, endothelial cells and macrophages are recruited by an even more complex group of signaling cues, growth factors, cytokines, chemokines, and small molecules, to direct the tissue-level response to repair. When compounding factors are included, for example microbial biofilms and genetic predispositions to chronic wounds, the daunting nature of the problem becomes more apparent. To develop an understanding of the cellular and molecular mechanisms involved in wound healing requires new approaches for characterizing the chemistry/biochemistry of the signal cascades. Single-cell, and sub-cellular studies are key to helping reveal the rules of wound healing, where reductionist approaches can be applied to unravel the complexity present. The distribution of bioelectronic chemical cues, in a sense, electrophysiology beyond the neuron, related to the bioelectric flow of extracellular currents of ions and molecules in a diverse range of tissue types is key to understanding wound healing. Such bioelectric currents are difficult to study, and have been a long-sought, but remain an under explored aspect of physiology. Historically, such ÒelectroceuticalÓ approaches have been explored at large (mm) scales in wound healing and tissue development applications, modern techniques of bioanalytical interrogation have only been employed in rare examples. Bioelectric cues are key to the development of an organized tissue response to wound healing, with a key example being polarization of epithelia which creates a barrier to ion and molecule transport. Long-term, we seek to determine the relationship of induced extracellular currents on chemical concentration gradients (e.g, pH, reactive-oxygen species (ROS), chemical messengers) at a wound-healing model on sub-cellular scales. In this Short-Term Innovative Research (STIR) project, we will demonstrate proof-of-principle in experiments designed to understand chemical and ion gradients in the extracellular environment at sub-cellular scales, and the role that electroceuticals play in these processes by correlating molecule/ion concentrations with a combination of advanced electrochemical imaging tools (scanning ion conductance microscopy, SICM), machine-learning guided image processing/analysis and molecular biology tools. Efforts in this nine-month application will be directed toward two specific tasks. A first task is demonstration of electrochemical mapping of chemical concentration gradients and subsequent quantitation with machine learning image processing, at sub-cellular scales of well-defined synthetic membrane models. A second task, building on the first task, will use an epithelial wound model and discrete electrical excitation to examine gradients of ROS at the leading edge of model at sub-cellular scales. This work will set the stage for addressing larger models, questions and opportunities in chemical/biochemical characterization of the effects of electroceutical approaches in wound healing, and how we can understand such processes at the subcellular level.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 25, 2021
- Source ID
- W911NF2110134
Entities
People
- Lane A Baker
Organizations
- Army Contracting Command
- Indiana University
- United States Army