Development of a microfluidic nanotoxicological-screening system with integrated sensors for a continuous monitoring of cell viability

Abstract

With technological advancement and the emergence of nanotechnology, many unique nanoparticles are being developed. These particles offer a broad range of industrial, consumer, and medical applications. However, nanoparticles can enter the body via different means such as inhalation or dermal uptake, and when inside the body, they can circulate in the bloodstream and travel to the surrounding tissues or other organs such as placenta, which can impair the viability of the fetus or cause early childhood complications. Nanoparticles have a different physicochemical characteristics compared to their bulk material, mainly due to their shape and size. Moreover, the high surface-to-volume ratio makes the nanoparticles extremely reactive, which potentially may result in oxidative stress, cytotoxicity, and genotoxicity. However, since the biological response to nanoparticles depends on their physicochemical properties, nanoparticles could interfere with some organic dyes used in cell-based assays, as well as with biological fluids such as cell culture medium. Therefore, the best approach to bypass limitations in nanotoxicity tests is to utilize at least two different in vitro toxicity or viability assays, as well as alternative screening methods such as microfluidics. In this study, bewo b30 cells, derived from human placenta choriocarcinoma, are used to assess the toxicity effects of different nanoparticles via in vitro assays on the placenta model. PrestoBlue cell viability assay is used to investigate the toxicity of various nanoparticles in the presence of serum, as well as their time-dependent toxicity. Furthermore, Image-iT ROS detection kit has been used to evaluate oxidative stress caused by different nanoparticles at different concentrations and exposure times, with and without the presence of serum. In this project, a microfluidic live-cell screening system with integrated optical oxygen sensors has been developed to analyze the nanotoxicity of different nanomaterials. Bewo b30 cells were cultured inside microfluidic chambers, representing a placenta model through which nanoparticles are passing or aggregated after exposure. Novel optical oxygen sensors have been integrated into the microfluidic chip. These sensors are label-free and non-invasive and enable fast and continuous monitoring of the cell-nanoparticle interaction during the entire exposure time. Different microfluidic protocols were established and optimized for both static and stop-flow measurements.