Blood-Derived Growth Factors

Abstract

Regenerative medicine is the science that studies the regeneration of biological tissues that are obtained through the use of cells, with the aid of supporting structures, and through the modulation of biomolecules. This definition embraces the different elements that allow the regeneration process to occur: the cell, which has the ability to produce new tissue; the scaffold, a three-dimensional structure that serves as a substrate for the regeneration of new tissue, and finally growth factors, i.e. signalling molecules with the capacity to modulate cell adhesion, survival, proliferation and differentiation.

Analysing growth factors in detail, we see that they can originate from platelets, from plasma, from the bone matrix, from osteocyctes and osteoblasts, from fibroblasts, and from bone marrow.

It thus emerges that a proportion of growth factors are derived from blood; blood is, indeed, an important source of growth factors that can be used to therapeutic ends.

The most widely used modality is the use of platelet-rich plasma (PRP), i.e. of the portion of plasma that, after centrifugation, is rich in platelets.

PRP contains numerous growth factors, the main ones being: platelet-derived growth factor (PDGF), transforming growth factor (TGF), platelet-derived endothelial growth factor (PDEGF), interleukin 1, insulin-like growth factor (IGF), osteocalcin and osteonectin, although there are many others.

Growth factors act by stimulating different cell mechanisms, including angiogenesis, macrophage chemotaxis, fibroblast proliferation and migration, collagen synthesis and, above all, the proliferation and differentiation of numerous cell types, including: mesenchymal stem cells, osteoblasts, fibroblasts, endothelial cells and chondroprogenitor cells.

PRP has been used successfully in orthopaedics for the biological regeneration of cartilage, tendons, ligaments and, of course, bone tissue.

With regard to bone tissue, very important use is made of blood-derived growth factors in the treatment of pseudoarthroses, the treatment of loss of bone substance, in prosthetic primary and revision surgery, and in the treatment of osteochondral defects.