growth factor

Growth factors are signaling proteins that act as instructions to cells, telling them to divide, move, or specialize into a particular cell type. They are the body's text messages: a cell releases one, it drifts to neighboring cells, and those that can read it change their behavior in response. This chemical chatter is how a body coordinates healing, growth, and the day-to-day upkeep of tissue.

Each growth factor fits a matching receptor on a target cell like a key in a lock. When the key turns, it flips switches inside the cell that may say grow now, crawl toward the wound, build a blood vessel here, or become a bone cell. Different factors carry different messages, and the exact mix and timing a cell receives steers what it ultimately does.

In regenerative medicine, growth factors are the third ingredient alongside cells and scaffolds — the instructions that tell the other two how to build. Engineers add them to scaffolds or bioinks to guide young tissue. But they are powerful and short-lived, and the same signal that heals can, in the wrong amount or place, drive unwanted growth, so dosing and delivery must be handled with great care.