Integrated optical biosensor for in-line monitoring of cell cultures

An analytical detection platform was developed to evaluate the induced toxicity in cell cultures exposed to foreign agents like growth factors or nanoparticles. Connecting a biosensing detection device to the cell culture flasks allows analyzing the composition of cell medium in real-time. The analysis relies on the quantification of inflammatory cytokines released by cells into the cell culture medium, by means of solid-phase immunoassays analyzed with the wavelength interrogated optical sensing (WIOS) instrument. A fluidic system for in situ measurements allows detecting cytokines in real-time, with a sensitivity of 1–100 ng/mL depending on the cytokine. In addition, integration of an in-line optical absorbance measurement unit, in combination with the standard AB cell proliferation assay, provides information on the cell viability in the culture. Fluidic connections between the cell culture flasks, the optical biosensor and the absorbance measurement unit simultaneously allow quantifying up to three cytokines (interleukin 8, interleukin 6 and the monocyte chemotactic protein), assessing cellular proliferation, and thus discriminating between naïve cells and cells exposed to foreign agents such as growth factors (tumor necrosis factor alpha) or nanoparticles. This analytical tool presents a high potential for assessing the cytotoxicity of nanoparticles and other chemicals in vitro.