Platelet rich plasma for biological therapy: Applications and limits

Platelets are not only the primary effectors of hemostasis, but also carriers of a variety of biologically active factors that can turn useful for therapeutic purposes, especially, although not exclusively, tissue healing. Recently characterized platelet-derived growth factors are able to favor tissue regeneration, wound healing and angiogenesis. The current availability of commercial methods to prepare Platelet Rich Plasma (PRP) has made its use quite popular, although there are still several areas of uncertainty on the biological efficacy of the preparations and even on their exact composition, making it essential to expand our knowledge on the events that characterize PRP action at least to standardize the methodologies. Although in some case-control studies and in several non-controlled clinical trials PRP has been found effective, studies on the efficacy of PRP in human subjects are not yet sufficient, probably because of its relatively recent clinical application. The results of most studies are hampered by relevant confounding variables such as the variability of PRP characteristics even in patients with similar platelet counts. We focus on the sate-of-the-art in this promising field.