A Conformable Organic Electronic Device for Monitoring Epithelial Integrity at the Air Liquid Interface

• Published in: Advanced materials (Weinheim) 2024-02, Vol.36 (8), p.e2306679-n/a
• Main Authors: Barron, Sarah L., Oldroyd, Sophie V., Saez, Janire, Chernaik, Alice, Guo, Wenrui, McCaughan, Frank, Bulmer, David, Owens, Róisín M.
• Format: Article
• Language: English
• Subjects: air liquid interface; Biocompatibility; Electrochemical impedance spectroscopy; Electrodes; Electrolytic cells; epithelial barriers; Equivalent circuits; flexible devices; Immunology; organic electronics; PEDOT: PSS; Toxicology
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202306679

Air liquid interfaced (ALI) epithelial barriers are essential for homeostatic functions such as nutrient transport and immunological protection. Dysfunction of such barriers are implicated in a variety of autoimmune and inflammatory disorders and, as such, sensors capable of monitoring barrier health are integral for disease modelling, diagnostics and drug screening applications. To date, gold‐standard electrical methods for detecting barrier resistance require rigid electrodes bathed in an electrolyte, which limits compatibility with biological architectures and is non‐physiological for ALI. This work presents a flexible all‐planar electronic device capable of monitoring barrier formation and perturbations in human respiratory and intestinal cells at ALI. By interrogating patient samples with electrochemical impedance spectroscopy and simple equivalent circuit models, disease‐specific and patient‐specific signatures are uncovered. Device readouts are validated against commercially available chopstick electrodes and show greater conformability, sensitivity and biocompatibility. The effect of electrode size on sensing efficiency is investigated and a cut‐off sensing area is established, which is one order of magnitude smaller than previously reported. This work provides the first steps in creating a physiologically relevant sensor capable of mapping local and real‐time changes of epithelial barrier function at ALI, which will have broad applications in toxicology and drug screening applications. Air liquid interfaced (ALI) epithelial barriers play vital roles in nutrient transport and immunological protection. Traditional electrical methods for measuring barrier integrity are ill‐adapted for soft tissue and require non‐physiological apical submersion. A novel flexible electronic device is presented that enables real‐time mapping of barrier function and disease in human airway and intestinal ALI samples, providing superior sensitivity, conformability, and biocompatibility.