Action mechanism of growth factors

It is known that growth factors act with cells according to endocrine, paracrine, autocrine, intracrine, juxtacrine, and matricrine mechanisms. Four mechanisms of the formers are diffusible and two of the latters non-diffusible. It is considered that the signal transduction of diffusible growth factors is significantly different from that of non-diffusible ones. It is important to design growth factors for tissue engineering, regenerative medicine, and cell culture system by taking the mechanisms into consideration.