Electrochemical Imaging of Endothelial Permeability Using a Large-Scale Integration-Based Device

Area of Science:

• Biomedical Engineering
• Cell Biology
• Electrochemistry

Background:

• Understanding biomolecule and chemical transport to tissues is crucial.
• Endothelial permeability is a key factor in physiological and pathological processes.
• Existing tracer-based assays often lack spatial resolution and require separate channels.

Purpose of the Study:

• To develop and validate an electrochemical imaging method for evaluating endothelial permeability.
• To demonstrate the method's capability in monitoring cellular responses and cancer cell metastasis.
• To provide a tool for advanced in vitro models like organs-on-a-chip and drug screening.

Main Methods:

• Utilized a large-scale integration device with 400 electrodes to monitor the diffusion of ferrocyanide ([Fe(CN)₆]^4-) through human umbilical vein endothelial cell (HUVEC) monolayers.
• Employed an electrochemical approach where tracer consumption at electrodes quantifies diffusion across the cell layer without separate channels.
• Validated the method by assessing the impact of histamine and monitoring endothelial permeability during co-culture with cancer spheroids.

Main Results:

• The electrochemical currents directly correlated with endothelial permeability.
• The method successfully detected changes in permeability induced by histamine.
• Spatial information was obtained, enabling monitoring of interactions between HUVEC monolayers and cancer spheroids, indicative of metastasis.

Conclusions:

• The developed electrochemical imaging method offers a sensitive and spatially resolved approach to assess endothelial permeability.
• This technique is a promising advancement for organs-on-a-chip systems and in vitro drug screening.
• The method provides valuable insights into cellular interactions and barrier function in complex biological models.