Platelet-Rich Plasma (PRP): Molecular Mechanisms, Actions and Clinical Applications in Human Body.

Platelet-rich plasma (PRP) is an autologous blood-derived concentrate increasingly utilized in regenerative medicine for its ability to accelerate healing and tissue repair. PRP is broadly classified by leukocyte content, fibrin architecture, and platelet concentration, with classification systems developed to standardize characterization. Preparation methods, including single- or double-spin centrifugation and buffy coat techniques, influence the final composition of PRP, determining the relative proportions of platelets, leukocytes, plasma proteins, and extracellular vesicles. These components act synergistically, with platelets releasing growth factors (e.g., VEGF, PDGF, TGF-β) that stimulate angiogenesis and matrix synthesis, leukocytes providing immunomodulation, plasma proteins facilitating scaffolding, and exosomes regulating intercellular signaling. Mechanistically, PRP enhances tissue repair through four key pathways: platelet adhesion molecules promote hemostasis and cell recruitment; immunomodulation reduces pro-inflammatory cytokines and favors M2 macrophage polarization; angiogenesis supports vascular remodeling and nutrient delivery; and serotonin-mediated pathways contribute to analgesia. These processes establish a regenerative microenvironment that supports both structural repair and functional recovery. Clinically, PRP has been applied across multiple specialties. In orthopedics, it promotes tendon, cartilage, and bone healing in conditions such as tendinopathy and osteoarthritis. In dermatology, PRP enhances skin rejuvenation, scar remodeling, and hair restoration. Gynecology has adopted PRP for ovarian rejuvenation, endometrial repair, and vulvovaginal atrophy. In dentistry and oral surgery, PRP accelerates wound closure and osseointegration, while chronic wound care benefits from its angiogenic and anti-inflammatory effects. PRP has also favored gingival recession coverage, regeneration of intrabony periodontal defects, and sinus grafting. Although preparation heterogeneity remains a challenge, PRP offers a versatile, biologically active therapy with expanding clinical utility.