Quantification of varying adhesion levels in chondrocytes using the cytodetacher

The potential to promote cell adhesion must be evaluated in the development of tissue-engineered implants and scaffolds. One measure of cell adherence is the force necessary to detach the cell. The objective of this study was to evaluate the cytodetacher (Athanasiou, K. A., et al. Development of the cytodetachment technique to quantify cellular adhesiveness. Biomaterials 20: 2405-2415, 1999), modified to test cells grown on substrata, as a means of calculating cell adhesion forces. Live and formalin-fixed bovine and rabbit chondrocytes underwent cytodetachment to verify that the cytodetacher provides satisfactory resolution to differentiate between live and fixed cells. Fixed cells had significantly greater mechanical adhesiveness than those prepared live: the values for the fixed rabbit and bovine chondrocytes were 1.01 and 1.56 microN, respectively, versus 0.14 and 0.17 microN for the live cells (p<0.05). The sensitivity of the cytodetacher was also gauged by detaching live rabbit chondrocytes seeded for varying amounts of time (40, 80, and 120 min). For the 40, 80, and 120 min time points the maximum detachment forces were found to be significantly different: 2.87 x 10(-2), 6.75 x 10(-2), and 14.30 x 10(-)2 microN, respectively. This study validates the use of the modified cytodetacher as an effective means of evaluating the strength of adhesion of cells attached to a substratum.