Life in an optical fiber: Monitoring of cell cultures with microcavity in-line Mach-Zehnder interferometer

Abstract

Monitoring cell adhesion and growth are crucial for various applications involving drug screening, cytotoxicity, and cytocompatibility studies. However, acquiring accurate information about the growing state and responsiveness to a treatment of a cell system in a real-time and label-free manner is still a challenge. This work presents the first research on direct, real-time, and label-free adherent cell culture monitoring using a microcavity in-line Mach–Zehnder interferometer (μIMZI) fabricated in an optical fiber. The sensing solution based on μIMZI offers a great advantage over many other monitoring concepts tracking the changes taking place on the microcavity's bottom surface and within its volume, thus offering a greater penetration depth. In this study, we verified performance of the approach using a non-cancer bone marrow stromal cell line HS-5. The results demonstrate that the changes of the acquired signal are closely related to the different states of cells' adhesion, proliferation, morphology, and variation of mass. Thus, this label-free, real-time μIMZI-based monitoring technique gives a great promise to the analysis or monitoring of relevant new treatments in future scientific, as well as clinical applications.