Chapter 11 - Platelet-Rich Plasma Incorporated Nanostructures for Tissue Engineering Applications

Abstract

Platelet-rich plasma (PRP) is a concentrated form of autologous platelets, releasing various growth factors (GFs) when activated. The activated form usually releases a number of growth factors and cytokines in physiologically relevant ratios, although in concentrations several times higher than that of normal blood that is critical to tissue regeneration. The PRP growth factors include platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and epidermal growth factor (EGF). It is believed that these high concentrations of growth factors have significant effects on the regeneration of bone, tendon, skin, and cartilage including cell proliferation, differentiation, and improved synthesis of extracellular matrix (ECM). On the other hand, PRP can be an inexpensive and immunologically safe source of various GFs delivery. However, the efficacy of PRP for tissue regeneration is usually problematic due to its rapid inactivation and the initial burst release of GFs. Consequently, an appropriate delivery system is required for local sustained release of GFs from active-state PRP to stimulate proliferation, synthesize ECM and so on. Incorporation of PRP into nanostructures is an alternative approach for having control over sustained release of growth factors. In the present study, some proposed methodologies to load PRP and GFs into nanostructures, such as exploiting heparin conjugated nanospheres, electrospun nanofibers, graphene (oxide) and nanoliposomes are discussed comprehensively.