Glioma-on-a-chip for investigating gliomagenesis and temozolomide treatment under static and continuous flow conditions

Gliomas constitute the most prevalent class of primary cancers in the central nervous system and arise from the brain's supportive glial lineage. Therapeutic outcomes remain suboptimal, mainly owing to the tumor's highly invasive phenotype and its heterogeneous microenvironment. Among them, glioblastoma (GBM) is associated with dismal prognosis and high mortality despite current multimodal clinical management. Advancing effective treatment strategies requires a deeper understanding of GBM pathobiology. Conventional two-dimensional (2D) static culture systems fail to capture the complexity of the tumor microenvironment. They cannot emulate the dynamic biochemical and biophysical cues present in vivo, underscoring the need for more physiologically relevant platforms. Furthermore, the inabilities of conventional systems motivate studies of the development of patient-tailored treatments, prompting the emergence of diverse three-dimensional (3D) microfluidic systems designed to model glioma biology. Microfluidic organ-on-chip technologies, which enable continuous perfusion, offer the capacity to replicate in vivo–like metabolic activity and microenvironmental conditions. Microfluidic platforms that recapitulate key features of the tumor microenvironment hold considerable promise for generating physiologically relevant in vitro glioma models, enabling systematic analyses of treatment responses. Such platforms may reduce the reliance on in vivo animal studies and facilitate the evaluation of drug regimens. In this thesis, a biologically realistic glioma model is developed by integrating GBM cells, an engineered hydrogel, and a custom-designed microfluidic chip. Additionally, the chip system developed in this study offers ease of use due to its simplified design, which allows for the injection of cell-laden biomaterial using syringe needles. Given that hyaluronic acid (HA) is a significant component of the GBM extracellular matrix and plays a key role in tumor progression, HA is selected in combination with gelatin methacrylate (GelMA) as the hydrogel system to recapitulate native GBM microenvironmental cues. GBM cells were subsequently cultured within the PDMS-based microfluidic platform and evaluated in terms of cell viability and gene expression profiles. Molecular biomarkers of gliomagenesis (e.g., EGFR) were investigated for human GBM cell lines (e.g., U87-MG) cultured under static and continuous flow conditions. Temozolomide treatment studies were conducted to evaluate drug responsiveness within the dynamic culture system. This thesis aimed to overcome the limitations of traditional 2D culture by establishing a 3D, dynamically perfused glioma-on-a-chip system, which integrates a hydrogel with a chip-based architecture that more faithfully replicates GBM tumor physiology to assess drug responses. It provides a robust framework for interrogating glioma biology and assessing therapeutic strategies.