Measurement of intercellular cohesion by tissue surface tensiometry.

Intercellular adhesion plays a vital role in many biological processes including embryonic development, malignant invasion, and wound healing, and can be manipulated to generate complex structures in tissue engineering applications. Accurate measurement of the strength of intercellular adhesion is not trivial and requires methods rooted in sound physical principles. Tissue surface tensiometry (TST) rigorously quantifies intercellular cohesive energy of 3D tissue-like aggregates under physiological conditions. TST utilizes a custom-built tensiometer to compress 3D spheroids between parallel plates. The resistance to the applied force and changes in aggregate geometry are applied to the Young-Laplace equation, generating a measurement of apparent surface tension. We describe all components comprising the tensiometer and provide step by step instructions of all the key steps involved in generating spherical aggregates. We explain how tissue surface tension is calculated and provide a statistical analysis of a sample data set from 12 aggregates.