Endothelial cell spheroids as a versatile tool to study angiogenesis in vitro

Area of Science:

• Biomedical Engineering
• Cell Biology
• Pharmacology

Background:

• Existing in vitro angiogenesis assays lack robustness and cost-efficiency for preclinical drug screening.
• A need exists for reliable models to analyze pro- and antiangiogenic compounds.
• Previous spheroid-based assays have not been fully evaluated for functional screening capacity.

Purpose of the Study:

• To develop and validate a robust, cost-efficient 3D in vitro angiogenesis assay.
• To assess the capacity of the assay for functional screening of compounds affecting angiogenesis.
• To determine the impact of 880 approved drugs on angiogenic sprouting.

Main Methods:

• Development of a 3D in vitro angiogenesis assay using collagen gel-embedded, size-defined spheroids from human umbilical vein endothelial cells (HUVECs).
• Time-lapse video microscopy to observe capillary-like sprout formation.
• Screening of 880 approved drugs for their effects on vascular endothelial cell growth factor 165-induced sprouting.
• Utilized immortalized HUVECs (iHUVECs) to improve assay robustness and reduce variability.

Main Results:

• The assay successfully demonstrated tip cell-led, partially lumenized sprout formation.
• Physiologic concentrations of vascular endothelial cell growth factor 165 induced sprouting from various endothelial cell types.
• The assay allowed for rapid and reproducible determination of functional IC50 values for individual compounds.
• Drug screening identified compounds that interfere with or boost angiogenic sprouting.

Conclusions:

• The spheroid-based angiogenesis assay is a sensitive and versatile tool for studying angiogenesis.
• The assay is compatible with different endothelial cell types and can be improved using iHUVECs for enhanced robustness.
• This model aids in assessing drug side effects and identifying novel therapeutic applications related to angiogenesis.