Question

You coat a Petri dish with fibronectin and proteoglycans and culture cells on the dish. The cells adhere to the dish. You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added. What happens?

The cells do not adhere to the dish.

The cells lyse immediately.

The cells adhere as they normally do.

The cells die immediately.

The cells immediately change their phenotype.

Answer 1

Adding RGD tripeptides to a Petri dish previously coated with fibronectin and proteoglycans prevents cells from adhering normally to the dish due to inhibition of integrin receptor binding.

Step-by-step explanation:

Cell adhesion to biomaterial scaffolds is an essential aspect of tissue engineering and reparative medicine. When you coat a Petri dish with fibronectin and proteoglycans, you're creating a substrate that can actively engage integrin adhesion receptors on cells, promoting cell adhesion. The presence of RGD tripeptides in the culture dish competes with fibronectin for binding to integrin receptors because RGD is the cell-adhesion sequence in fibronectin. As a result, the cells in your experiment to which RGD tripeptides were added do not adhere to the dish as they normally do, due to the competitive inhibition of the adhesion process.