Glioblastoma (GBM) is the most common primary malignant brain tumor diagnosed in adults, carrying with it an extremely poor prognosis and limited options for effective treatment. Various cell therapies have emerged as promising candidates for GBM treatment but fail in the clinic due to poor tumor trafficking, poor transplantation efficiency, and high systemic toxicity. In this study, we design, characterize, and test a 3D-printed cell delivery platform that can enhance the survival of therapeutic cells implanted in the GBM resection cavity. Using continuous liquid interface production (CLIP) to generate a biocompatible 3D hydrogel, we demonstrate that we can effectively seed neural stem cells (NSCs) onto the surface of the hydrogel, and that the cells can proliferate to high densities when cultured for 14 days in vitro. We show that NSCs seeded on CLIP scaffolds persist longer than freely injected cells in vivo, proliferating to 20% higher than their original density in 6 days after implantation. Finally, we demonstrate that therapeutic fibroblasts seeded on CLIP more effectively suppress tumor growth and extend survival in a mouse model of LN229 GBM resection compared to the scaffold or therapeutic cells alone. These promising results demonstrate the potential to leverage CLIP to design hydrogels with various features to control the delivery of different types of cell therapies. Future work will include a more thorough evaluation of the immunological response to the material and improvement of the printing resolution for biocompatible aqueous resins.

Tumor-homing neural stem cell therapy (tNSC) is emerging as a promising treatment for aggressive cancers of the brain. Despite their success, developing tNSC therapies that maintain durable tumor suppression remains a challenge. Here, we report a new synergistic combination regimen where the novel agent TR107 augments induced NSC-TRAIL therapy (hiNeuroS-TRAIL) in models of the incurable brain cancer glioblastoma (GBM). We found that the combination of hiNeuroS-TRAIL and TR-107 synergistically upregulated caspase markers and restored the sensitivity to the intrinsic apoptotic pathway by significantly downregulating inhibitory pathways associated with chemoresistance and radioresistance in GBM. This combination regimen showed dramatic tumor suppression and enhancement of survival of mice bearing human xenografts of both solid GBM and established invasive GBM. The combination also synergistically suppressed tumor growth in low-passage patient derived GBM cells established with an ex vivo brain slice platform. These findings elucidate a novel combination regimen and suggest combination of these clinically relevant agents may represent a new therapeutic option with increased potency for GBM patients.

Therapeutic neural stem cells (tNSCs) are a promising new platform for the treatment of glioblastoma (GBM). tNSCs exhibit a characteristic known as tumor tropism, in which they can migrate towards distant GBM foci via cytokine signaling. Complementarily, genetic engineering of NSCs may be performed to turn the cells into drug-producing therapeutics. Together, this results in NSCs that act as targeted drug delivery vehicles that can seek out and kill invasive GBM lesions post-resection. However, one limitation of this cell therapy platform is that tNSCs delivered directly into the GBM resection cavity are rapidly cleared. We hypothesized that the commercially available, FDA-approved hemostat FLOSEAL® may be used as a drug delivery system for improving cell persistence in the brain, thus resulting in improved therapeutic efficacy. It was found that tNSCs encapsulated in FLOSEAL® were detectable in the brain for over 95 days in mice, a drastic improvement compared to directly injected cells and cells encapsulated in other existing hemostat systems, which persisted 2 weeks or less. However, two in vivo efficacy studies of tNSCs encapsulated in FLOSEAL® yielded contrasting results. While the FLOSEAL®-tNSC system was significantly more efficacious against a GBM8 tumor model in mice compared to directly injected tNSCs, it was not significantly more effective against a U87 tumor model. This could be due to a variety of factors, including the tumor type (diffuse vs. solid for GBM8 and U87, respectively) and negative impacts of FLOSEAL® on tNSC markers of proliferation, migration, drug production, and anti-apoptosis. While FLOSEAL® is a promising material for the delivery of tNSCs in the treatment of post-operative GBM, alternative systems that allow for improved persistence while maintaining the therapeutic activity of the cells would be optimal for long-term treatment with tNSCs.