Plasma rich in Growth Factors (PRGF) Growth factors are proteins that play an essential role in the complex processes of tissue repair and regeneration. When they are in association with surgery, they provoke a rapid response that accelerates the regeneration of damaged tissue. Where are some of the growth factors located? The growth factors are found mainly in the plasma and the interior of platelets stored in their cytoplasmic granules, there are some that are directly related to the repair of tissues.