Bioengineering Stem Cell-Derived Glioblastoma Organoids: A Comprehensive Review.

The development of novel therapeutics for deadly diseases such as glioblastoma (GBM) is bottlenecked by poor preclinical models. GBM is the most common and deadliest primary brain tumor in adults, with an average prognosis of 12-15 months, primarily due to its high cellular heterogeneity and treatment resistance from GBM stem cells. The advancement of in vitro models into organoids, three-dimensional tissue-like modeling systems, has been a promising approach to improving translational medicine for GBM. However, the critical tradeoff between technical convenience and physiological relevance threatens the integrity and reproducibility of GBM organoid (GBO) biomanufacturing. This comprehensive review breaks down and discusses the key features of GBM tumor microenvironment (TME), traces the advancement of in vitro models from two-dimensional cultures to three-dimensional stem cell-derived GBOs, evaluates the process through an engineering perspective (genetic, biochemical, biophysical, and process engineering), and addresses critical translational gaps. Reviewing trends over the last fifteen years in biomanufacturing approaches to GBOs revealed fundamental oversights that address previous review focuses on the limitations of organoids (i.e., maturity, vasculature, and immune defense). To summarize, GBO's translational gap and reproducibility challenges are rooted in the prioritization of technical convenience over physiological relevance. To achieve clinical relevance, future GBO development must focus on transitioning to fully defined components (excluding animal-derived ECM), developing sufficiently large-sized constructs to recapitulate the full TME, and integrating non-destructive and enhanced functional readouts of the GBOs.