Mimicking tumor hypoxia in a glioblastoma-on-a-chip.

Glioblastoma (GBM) is one of the most aggressive and lethal brain tumors, characterized by limited therapeutic options and poor prognosis. This condition is strongly linked to the limitations of current preclinical models: traditional two-dimensional cell cultures and animal models often fail to recapitulate the complexity of the tumor microenvironment (TME), resulting in limited predictive value for clinical outcomes. Here, a biomimetic three-dimensional (3D) in vitro culture system is presented, designed to incorporate key components of the TME and to mimic human GBM biology by: (i) employing ad hoc-designed hydrogels as extracellular matrix (ECM) equivalents; (ii) integrating multiple cell types, namely GBM cells and astrocytes; and (iii) implementing dynamic cell culture conditions through a custom-designed microfluidic platform that closely resembles the hypoxic conditions typically found in this tumor. In parallel, an in silico model is developed to evaluate key microfluidic parameters, including flow velocity, diffusive and convective transport within the system, and spatiotemporal oxygen distributions. Experimental validation combined with computational modeling enables optimization of device design and conditions to better replicate hypoxic GBM microenvironments. The GBM-on-Chip platform highlights the potential of advanced 3D systems to improve physiologically relevant in vitro cancer models and support future drug testing and therapy development.