In vitro vascular invasion assay for the study of (the role of cellular forces in) sprouting angiogenesis

Scope of the method

Method relates to
  • Human health
Method is situated in
  • Basic Research
Type of method
  • In vitro - Ex vivo
This method makes use of
  • Human derived cells / tissues / organs
Specify the type of cells/tissues/organs
Endothelial cells

Description

Method keywords
  • endothelial cells
  • live optical microscopy
  • extracellular matrix
  • hydrogel
  • Image analysis
  • matrix mechanics
  • traction force microscopy
Scientific area keywords
  • microvascular biology
  • angiogenesis
  • cell mechanics
  • mechanobiology
  • bioengineering
  • biomechanics
  • biomaterials
Method description

The method enables to quantitatively assess the invasion of endothelial cells in extracellular-matrix mimicking hydrogels, such as collagen or polyethylene glycol, and to measure the forces exerted by the cells that enable them to invade. Endothelial cells are seeded on the side of a hydrogel and cultured in pro-angiogenic medium to induce sprouting angiogenesis. Live cell imaging of endothelial cells is performed by means of confocal laser scanning microscopy. Fluorescent nanobeads are incorporated in the hydrogel to track the deformations of the hydrogel during endothelial invasion. Mechanical (elastic) properties of the hydrogel are measured. Cellular forces applied by the endothelial cells during invasion are inferred from the measured hydrogel deformations and mechanics.

Lab equipment
  • Biosafety cabinet ;
  • Incubator ;
  • Confocal microscope.
Method status
  • Published in peer reviewed journal

Pros, cons & Future potential

Advantages
  • High resolution imaging of cell dynamics ;
  • Unique method to quantity cellular forces.
Challenges
  • Extension to long-term imaging (several days) ; 
  • More complex extracellular matrix environments (including co-culture systems) ;
  • Medium-to-high throughput screening is still challenging.
Future & Other applications

The method enables to screen different micro-environments for their effect on vascular invasion / sprouting angiogenesis, which is among others, relevant for regenerative medicine and diseases that affect angiogenesis. It offers a unique way of exploring the role of (abnormal) cellular forces in the etiology of diseases that affect microcapillaries.

References, associated documents and other information

References

Vaeyens, M-M., Jorge Peñas, A., Barrasa Fano, J., Steuwe, C., Heck, T., Carmeliet, P., Roeffaers, M., Van Oosterwyck, H. (2020). Matrix deformations around angiogenic sprouts correlate to sprout dynamics and suggest pulling activity. Angiogenesis. doi: 10.1007/s10456-020-09708-y

Associated documents

Contact person

Hans Van Oosterwyck

Organisations

KU Leuven
Mechanical Engineering
Belgium
Flemish Region