New and Emerging Strategies in Platelet-Rich Plasma Application in Musculoskeletal Regenerative Procedures: General Overview on Still Open Questions and Outlook

Table 1

Main GFs release by α-granules.

GFs	Mechanism of action
TGF-β	(i) MSC proliferation and differentiation; (ii) Cell mitogenesis; (iii) Collagen II, proteoglycan, and ECM synthesis; (iv) Endothelial chemotaxis and angiogenesis; (v) Macrophages and lymphocyte proliferation inhibition; chondrocyte differentiation; (vi) TIMP upregulation
PDGF-a and -b	(i) OBs and MSCs mitogenesis; (ii) Macrophages, neutrophil, and other cell chemotaxis; collagen I synthesis
bFGF	(i) Chondrocyte and OB differentiation; (ii) MSCs, chondrocyte, and OB mitogenesis
EGF	(i) Endothelial chemotaxis and angiogenesis; (ii) Collagen synthesis; (iii) MSC and epithelial cell mitogenesis
CTGF	(i) Angiogenesis; (ii) Cartilage regeneration; (iii) Fibrosis; (iv) Platelet adhesion
VEGF	(i) Angiogenesis; (ii) Endothelial cell mitogenesis
IGF	(i) Cell proliferation; (ii) Collagen synthesis; (iii) Myoblast proliferation and differentiation