Physiological Microsystems with on-chip and off-line characterization of nano-pollutants evolution in biofluids and impacts on endoThelium and hemostasis – ModerniT

Nano-pollutants (NPs) are widely present in our environment with a recognized impact on the health of the population. It has been shown that NPs are able to enter the blood vessels, increase risk of cardiovascular diseases, induce endothelial rupture and alter the human body ability to self-repair including hemostasis. However, the mechanisms between the exposure to NPs and the effects on the organism are still poorly understood. The objective of the ModerniT project is therefore to develop a lab-on-chip type platform to follow the evolution of NPs in the bloodstream and to evaluate their vascular toxicity. To achieve this objective the project will be divided into two parts: (1) after a set of physicochemical characterizations, which will constitute a reference, different types of NPs will be injected into a microfluidic circuit reproducing the vascular network. NPs will be transported in channels with a simplified biofluid (PBS+proteins, plasma) controlled in flowrate, pH and temperature. During circulation it is known that protein corona forms around NPs, whose composition varies with NPs type and time. Accordingly, optical dynamic scattering sensor will be integrated in the microfluidic device to monitor in-situ and in real time the evolution of the hydrodynamic size of NPs. Electrodes will also be integrated in the device to follow the modification of surfaces charges. After circulation, we will repeat the physicochemical characterizations of NPs to compare them to the reference values. Thanks to this microfluidic device we will also be able to produce NPs modified by the circulation in complex biofluids such as plasma and whole blood for the analysis conducted in the second part. (2) These NPs will be introduced into 3 different microdevices for the detailed evaluation of vascular toxicity. A first microfluidic device designed as an organ-on-a-chip will reproduce the interaction of NPs in flow with human endothelial cells and 3D models of blood capillaries to evaluate the impact of NPs on human vascular tissues. Then, we will evaluate the effects of the modified NPs on primary and global hemostasis phenomena. For primary hemostasis we will use an in-flow microdevice developed during a previous ANR project (GHOST) working in whole blood environment. Finally, thrombus formation will be studied with a commercial in-flow device (T-TAS01).
Our project presents 3 advantages over state-of-the-art practices:
- the in vitro assay with organ-on-chip (OoC) like physiological microsystem is a relevant alternative to animal use in predictive toxicology
- the combination of 3D cell organization and physiological like test conditions strongly improves the robustness of the toxicological prediction. With the technology of tissue engineering, OoC can be developed to consider the effects of shear stress, mechanobiology, spatial organization and extracellular matrix.
- Unlike in vivo studies, which provide an overall evaluation of vascular toxicity, this project uses 3 different evaluations (endothelium, primary and global hemostasis) to have a better mechanistic understanding of the toxicity cause. Understanding the mechanisms involved at the level of NPs in their environment will help to establish a correlation with the health state of the population.