Optimizing a 3D microfluidic platform for personalized lung cancer drug screening

Despite recent advances in immunotherapies for lung cancer, their success is still hindered by limited predictability of treatment outcomes in patients, as well as by resistance-conveying tumor mutations such as EGFR. Moreover, due to the vast number of treatment options and their cost, a quick, reliable, and cost-efficient drug screening platform is needed to select the optimal treatments for each individual patient. This thesis focuses on finding the best culture conditions to be used in such a future platform, employing 3D cell cultures and microfluidics to mimic in vivo tumors while saving costs and allowing for high-throughput screening. Image-based analysis showed that culture medium can have significant impacts on both cancer organoid growth and morphology, as well as drug sensitivity to the EGFR-inhibiting drug Osimertinib. Specific medium factors, such as the antioxidant N-acetylcysteine, might be particularly important for the integrity of 3D structures in the platform and help prevent conversion to an adherent morphology. Moreover, flow cytometry analysis of immune cells from pleural effusion samples indicated that medium composition might facilitate creating an inflammatory environment in the platform, and that immune cells should not be cultured longer than one week to maximize their activity. Finally, this thesis compares two microfluidic devices for their suitability to be used in future high-throughput drug-screening applications, by contrasting their ease of handling, applicability in fluorescent imaging-based readouts, and possibility to mimic and study the tumor microenvironment in vitro. The results suggest that the choice of microfluidic device will be dependent on whether microscopy analysis or cell viability assays will be used as the main readout of the drug screening in the future