A Convenient and Efficient Centrifugation Assay for Comparing Cell Adhesion Strength on Uncharted Surfaces

Abstract

Regulating cell-substrate adhesion is of fundamental importance in biomaterial design and development. While an increasing number of approaches are being developed to quantify cell adhesion strength, only a fraction of these techniques provide measurements that are simple and sensitive at the living cell population level. In our previous study, the expression of adhesion-associated proteins in fibroblasts was found to change on ion-implanted silicone rubber; however, the actual effects of the modified surfaces on cellular mechanical properties remain to be probed. Here, we proposed a convenient method to compare the cell adhesion strength on various surfaces, for multiple adhesion periods and with different cell types. This method requires only common laboratory equipment. In addition, we introduced a new parameter, ECS50, which is appropriate for screening optimum centrifugal conditions when the cell affinity of the surface as a control is initially unknown. This parameter is helpful for further exploration of cell affinity on all the biomaterials of interest. The results demonstrate that this centrifugation assay is simple, efficient and adaptable in investigating the overall adhesion strength of living cells under various conditions, and therefore, it is a valid way to develop adhesion-controlled biointerface materials in the future.