Development and characterization of a biotechnological model suitable for studies of tumor cell extravasation and intravasation

Metastatic dissemination remains the leading cause of mortality in malignant tumors, yet the processes of intravasation and extravasation of circulating tumor cells (CTC) are still not fully understood. Existing microfluidic experimental systems possess a number of limitations that prevent them from reproducing physiological conditions. Here we propose a perfused biotechnological system designed to model key stages of the metastatic cascade under controlled flow. The construction includes a parallel-plate flow chamber formed between polyethylene terephthalate plates and surrounded by a collagen gel containing life human dermal fibroblasts. Matrix parameters were optimized, and it was established that a collagen concentration of 20 mg/mL provides mechanical stability, sustained cell viability, and gel robustness under flow. The system also supports the formation of a two-component cellular microenvironment: fibroblasts embedded within the matrix and endothelial cells forming a layer on its surface. An integrated open reservoir effectively eliminated air bubbles and stabilized hydrodynamics, representing a major advantage over conventional microfluidic systems. 48 hour long perfusion of full medium with cells demonstrated long-term cell viability and preservation of channel geometry under continuous perfusion. The developed system combines the benefits of 3D hydrogels and dynamic models while overcoming critical limitations of classical microfluidic devices, and it may serve as a reproducible platform for studying mechanisms of metastasis.