Making cells feel like at home: Are microfluidic systems ready for use in a Next-Generation Risk Assessment toolbox?

Traditional animal testing is often slow, costly, and can fail to accurately predict risks to humans. Consequently, chemical safety testing is shifting toward Next-Generation Risk Assessments, which use computer models and human cells. A key innovation in this field is the use of microfluidic system devices. These devices allow human cells to grow in 3D environments with flowing nutrients, making them "feel at home" by mimicking the natural conditions of the human body. This PhD research investigated whether these systems are ready for future routine safety testing. The study suggests a major challenge: many chemicals are lost through evaporation or binding to the system’s materials before reaching the cells. However, when applied to the study of liver conditions such as impaired bile flow (cholestasis), the results showed great promise. Overall, this work highlights that with further optimisation, microfluidic systems can become powerful, more accurate tools for predicting human safety concerns without animal testing.