Cholangiocarcinoma-on-a-chip: A human 3D platform for personalised medicine.

Background & Aims: Cholangiocarcinoma (CCA) is a primary liver tumour characterised by a poor prognosis and limited therapeutic options. Available 3D human CCA models fail to faithfully recapitulate the tumour niche. We aimed to develop an innovative patient-specific CCA-on-chip platform. Methods: A CCA tumour microenvironment was recapitulated on a microfluidic three-channel chip using primary CCA cells, cancer-associated fibroblasts (CAFs), endothelial cells, and T cells isolated from CCA specimens (n = 6). CAF and CCA cells were co-cultured in the central channel, flanked by endothelial cells in one lateral channel, recreating a tubular structure. An extensive characterisation of this platform was carried out to investigate its diffusion ability, hydrogel properties, and changes in matrix composition. Cell phenotype and functional properties were assessed. Results: Primary cells seeded on the microfluidic device were shown to reproduce the architectural structure and maintain the original phenotype and functional properties. The tumour niche underwent a deep remodelling in the 3D device, with an increase in hydrogel stiffness and extracellular matrix deposition, mimicking Conclusions: We presented a 3D CCA platform that integrates the major non-immune components of the tumour microenvironment and the T cell infiltrate, reflecting the CCA niche. This CCA-on-chip represents a reliable patient-specific 3D platform that will be of help to further elucidate the biological mechanisms involved in CCA and provide an efficient tool for personalised drug testing. Impact and implications: An innovative patient-specific cholangiocarcinoma (CCA)-on-chip platform was successfully developed, integrating the major components of the tumour microenvironment (tumour cells, cancer-associated fibroblasts, endothelial cells, and immune infiltrate) and faithfully mimicking the CCA niche. This CCA-on-chip represents a powerful tool for unravelling disease-associated cellular mechanisms in CCA and provides an efficient tool for personalised drug testing.