A novel quantitative angiogenesis assay based on visualized vascular organoid.

Angiogenesis describes the sprouting of blood vessels from existing vasculatures and it plays a pivotal role in disease progress such as diabetes, age-related macular degeneration and cancer. However, the most widely used anti-angiogenic agents targeting vascular endothelial growth factor (VEGF) pathway still lacked of specificity and therapeutic efficacy. To establish a method suitable for high-throughput drug screening and faithfully recapitulate the feature of in vivo angiogenesis, we generated a PECAM1-mRuby3-secNluc; ACTA2-EGFP dual reporter human pluripotent stem cell (hPSC) line and utilizing the cell line to establish a visualized and quantifiable in vitro angiogenesis model with stem cell-derived vascular organoid. Using this method, we evaluated the anti-angiogenic effect of VEGFR inhibitor and efficiently identified several potential candidates of pro- and anti-angiogenic therapy via bioluminescence-based quantification. Overall, our study provides a valuable platform for in vitro drug screenings.