A Biomimetic 3D Glioblastoma Triculture Model

<br/>Glioblastoma multiforme, or GBM, is an aggressive form of brain cancer that is hallmarked by highly immunosuppressive properties and therapeutic resistance. Recent studies have experimented with creating in vitro culture models of GBM tumors but are unable to adequately recapitulate the immunogenicity of the tumor microenvironment (TME). This may be due to a lack of multiple cell types, which are crucial to the heterogeneity of the microenvironment and GBM tumor characteristics. Expanding further upon the 3D bioengineered brain model established by Sood et. al, we proposed culturing glioblastoma cells, microglia, and astrocytes together to create a novel triculture model, first in 2D and then in a 3D porous silk scaffold supplemented with an ECM hydrogel. We have cultured the three lines at three different ratios to determine the optimal combination for harmonious proliferation in 2D. Quantitative viability and cytotoxicity assays (LDH, WST-1) were implemented to confirm survival and health of the cultures whereas qualitative immunostaining and fluorescent imaging were performed to observe cellular migration and proliferation. Once this optimal ratio was determined, the three cell types were seeded at four different total densities into porous 3D silk scaffolds infused with ECM hydrogels to observe spatiotemporal distribution of the cells over time (1 week and 4 weeks). Similar methods of analysis have been performed with the addition of two assays (CSPG ELISA, MMP assay) to quantify proteins associated with 3D culture characteristics. Further optimization of the GBM model will be determined through a drug screening implementing temozolomide, vincristine, and clomipramine to characterize the model’s immunosuppressive response against different therapeutic agents. The successful establishment of this 2D and 3D triculture model will provide researchers with a comprehensive GBM model for potential investigation into other properties of the tumor microenvironment and future development of therapeutics to treat this deadly disease.