Engineering multi cellular on-a-chip models for colorectal cancer studies

Microfluidics, a technology characterized by the engineered manipulation of fluids at the submillimeter scale, has shown considerable promise for improving diagnostics and biology research. Specific properties of microfluidic technologies, such as rapid sample processing and precise control of fluid in an assay, elected them as attractive candidates to replace conventional experimental methods in biological sciences. Microbioreactors are thus an important tool for obtaining an accurate control of cultured cells and tissues. Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-related death worldwide, with incidence projected to rise in the coming decades. Its development follows a multistep process driven by genetic and epigenetic alterations, influenced by lifestyle and environmental factors. While surgery is curative in early stages, advanced and metastatic disease often requires multimodal therapies, yet responses remain highly variable due to the biological complexity of CRC. A major driver of this complexity is the tumor microenvironment (TME), a heterogeneous network of stromal, endothelial, and immune cells embedded in the extracellular matrix. Within CRC, cancer-associated fibroblasts, abnormal angiogenesis, immune suppression, and hypoxia collectively sustain tumor growth, invasion, and resistance to therapy. These features highlight the need for advanced preclinical models capable of faithfully reproducing CRC-TME interactions. The aim of this work is to investigate CRC and its TME through the development and application of an advanced microfluidic platform. This device will enable integrated studies of multiple aspects of metastatic microenvironments with a high level of control and experimental flexibility. Within this context, the work focuses on dissecting the interplay between CRC cells and different stromal components of the TME. Particular attention is devoted to the role of fibroblasts, which profoundly influence tumor progression, as well as to the contribution of extracellular matrix, which regulate CRC growth and invasiveness. Furthermore, the interaction with immune elements is explored, aiming to better understand how tumor-immune crosstalk shapes disease outcomes and therapeutic responses. By integrating these aspects, the thesis aims to provide new insights into the complex mechanisms driving CRC progression and to contribute to the establishment of more predictive preclinical models.