Vascularization ability of glioma stem cells in different three-dimensional microenvironments

Glioblastoma (GBM) is among the most common and aggressive adult central nervous system tumors. One prominent characteristic of GBM is the presence of abnormal microvessels. A significant correlation between angiogenesis and prognosis has been observed. Accurately reconstructing this neovascularization and tumor microenvironment through personalized in vitro disease models presents a significant challenge. However, it is crucial to develop new anti-angiogenic therapies for GBM. In this study, 3D bioprinted glioma stem cell (GSC)-laden hydrogel scaffolds, hybrid GSC hydrogels and cell-free hydrogel scaffolds were manufactured to investigate the vascularization ability of GSCs in varying 3D microenvironments. Our results demonstrated that the bioactivity of GSCs in the 3D bioprinted GSC-laden hydrogel scaffold was preferable and stable, and the amounts of vascular endothelial growth factor A and basic fibroblast growth factor were the highest in the microenvironment. When the three different models were co-cultured with human umbilical vein endothelial cells, the expression of angiogenesis-related markers was the most abundant in the bioprinted GSC-laden hydrogel scaffold. Additionally, xenograft tumors formed by bioprinted GSC-laden hydrogel scaffolds more closely resembled human gliomas regarding color, texture and vascularization. Notably, in xenograft tumors derived from 3D bioprinted GSC-laden hydrogel scaffolds, the number of human CD105⁺ cells was significantly higher, and human endothelial vascular lumen-like structures were observed. This indicates that the 3D bioprinted GSC-laden hydrogel scaffold is a suitable model for mimicking the glioma microenvironment and studying tumor angiogenesis.