Gelatin Methacrylate Hydrogel Suitability for Soft Polymer Glioblastoma Cell Culture

Glioblastoma multiforme (GBM) is an aggressive, deadly form of brain cancer with a prognosis of approximately 12-15 months. This bleak prognosis can be attributed to the ineffectiveness of current GBM treatment methods, which can be slow, painful, and expensive for patients. Advanced tissue and polymer engineering provide alternative avenues to improve GBM research, treatment, and therapy through the enhancement of organoid technology. In short, organoids are miniature organs grown in a dish and developed from stem cells that are induced into differentiation, typically through mechanical signaling from an extracellular scaffold such as a hydrogel. Conventionally, GBM stem cells are grown in vitro using tissue culture flasks made of polystyrene (TCPS). In this form, polystyrene is a hard plastic with a stiffness seven orders of magnitude greater than that of human brain tissue. Additionally, TCPS does not accurately depict the highly heterogenous tumor microenvironment (TME) of GBM. This project explores the mechanical properties of gelatin methacrylate (GelMA) and its compatibility with GBM organoids. GelMA was selected due to its cost efficiency, biocompatibility, and controllable stiffness. Samples of 3%, 5%, and 7% weight/volume GelMA hydrogels were synthesized using 3D-bioprinting techniques. Samples were mechanically characterized using various methods, including enzymatic degradation tests, fluid swell tests, and rheological testing, to determine which weight/volume percent exhibited a stiffness most similar to that of human brain tissue. Based on rheological testing, 5% weight/volume GelMA hydrogel was most similar to native brain tissue and is likely the best candidate for in vitro culture of GBM tumor cells in the presence of soft biopolymers. In conclusion, soft polymers like GelMA can closely model tumor microenvironments and improve cell culture conditions to further advance GBM organoid technology.