Platelet-rich plasma (PRP) is defined as a portion of the plasma fraction of autologous blood having a platelet concentration above baseline. PRP serves as a growth factor agonist and has both mitogenic and chemotactic properties. It contains a high level of platelets and a full complement of clotting and growth factors. In recent years, the use of platelet-rich plasma (PRP) has increased notably in a range of diseases and settings, such as wound healing, treatment of chronic skin and soft tissue ulcerations, the use of PRP include periodontal and oral surgery, maxillofacial surgery, orthopaedic and trauma surgery, cosmetic and plastic surgery, spinal surgery, infertility, heart bypass surgery and burns. Considering cutaneous ulcers, good outcomes have been found in case series and controlled studies in a wide variety of etiologies.
PRP functions as a tissue sealant and drug delivery system, with the platelets initiating wound repair by releasing locally acting growth factors via α-granules degranulation.
These growth factors aid healing by attracting un-differentiated cells in the newly formed matrix and triggering cell division. PRP may suppress cytokine release and limit inflammation, interacting with macrophages to improve tissue healing and regeneration, promote new capillary growth and accelerate epithelialization in chronic wounds.
Platelets in PRP also play a role in host defence mechanism at the wound site by producing signalling proteins that attract macrophages; PRP also may contain a small number of leukocytes that synthesize interleukins as part of a non-specific immune response.
PRP can be considered a secure treatment. No adverse effects, such as increased risk of infection or hypersensitivity reactions, have been detected in clinical trials. Regarding oncogenic potential, when possible coincidences between carcinogenesis and the mitogenic pathways employed by growth factors have been evaluated, no evidence supports a possible tumoral triggering. Once a growth factor has joined its membrane receptor, intracellular signal cascades are activated, normal genetic expression is promoted, and different control mechanisms regulate this process.
Chronic wounds that do not respond to conventional treatment are not rare, and thus constitute a real challenge for the clinician. PRP represents a viable alternative treatment for recalcitrant chronic ulcers, whose efficacy has been demonstrated both in vitro and in vivo. The design of clinical protocols and the extension of PRP use in wound-care centers could have an important socioeconomic impact and see improvement in patients’ quality of life. Regenerative medicine in wound healing is a continuously innovative area. Its objectives are both providing essential elements for damaged-tissue replacement and enhancing intrinsic regenerative capacity. Clinical experience shows that combination of different regenerative techniques such as stem cells may enhance healing.