Project Summary/Abstract Glioblastoma is the most common primary brain tumor and one of the deadliest forms of cancer. Recently, we found that biocompatible matrices significantly improve the transplant of tumor-homing neural stem cells into the post-surgical GBM cavity allowing them to deliver anti-cancer gene products that suppress tumor recurrence. Yet, the optimal scaffold figuration that maximizes tNSC transplant, migration, drug release, and subsequent GBM kill remain unknown. Using clinically relevant human tNSCs, matrices, and mouse models of GBM resection/recurrence, we have found that 3D architecture and scaffold composition markedly enhance tNSC persistence in the surgical cavity. Here in, we hypothesize that optimizing features through unique 3D printing of custom designed scaffolds will achieve superior suppression of post-surgical GBMs by tNSC therapy. Leveraging Continuous Liquid Interface Printing (CLIP), a novel continuous fabrication method with high spatial resolution, we propose to fabricate a panel of 3D matrices with different architectural, biophysical, and mechanical response features design rationally selected to improve tNSC therapy. We will define the impact of each design feature on tNSC persistence, homing and killing in vitro and in vivo, then test a final optimized matrix incorporating the most beneficial features into a single matrix using surgical resection models of patient-derived human xenografts in immune-depleted mice and syngeneic GBM allografts in immune- competent animals. We propose to undertake the following Aims: 1) Utilize CLIP to fabricate a panel of 3D printed matrices with varied design features; 2) Define the impact of 3D design features on tNSC efficacy for post-operative GBM; 3) Investigate the efficacy and safety of 3D matrix/tNSC therapy in immune-competent models of GBM resection/recurrence. The results of our study will generate a therapeutic tNSC/scaffold transplant strategy capable of robust GBM killing that can be translated for human patient testing. It will also uncover the scaffold features that regulate different aspects of tNSCs, allowing us to modulate tNSC cancer therapy through matrix design.