title: Platelet gels and releasates.
abstract: OBJECTIVE
  This review addresses potential roles for platelets and their derivatives (gels, releasates, and lysates) as therapeutic agents for regenerative medicine. Recognizing that activated platelets release chemotactic and growth factors, investigators have attempted to enhance tissue regeneration by applying platelets and various derivatives directly into sites of surgical interventions or injuries. This review analyzes the physiologic basis for this approach to tissue healing and examines the knowledge that has been derived from recent and relevant reports of in-vitro and in-vivo studies.
  
  
  RESULTS
  In-vitro studies have established that platelets and their derivatives accelerate proliferation of an array of cells involved in soft and bony tissue regeneration. These effects have been evaluated, also, in vivo in humans and in animals. The outcomes of in-vivo studies are considerable less homogeneous than the outcomes of in-vitro investigations. The resultant discrepancies reflect not only differences of technical protocols, but also the greater complexity of healing vital tissues compared with circumscribed in-vitro studies.
  
  
  CONCLUSIONS
  The preponderance of evidence indicates that platelets and their derivatives have the potential for a substantial therapeutic role in tissue regeneration. The results of recent research indicate that platelet-derived growth factors act in synergy with plasma-derived factors to activate a complex network of autocrine functions that modulate healing. Platelet-derivative products are promising therapeutics that offer new opportunities for research and applications of tissue engineering.
authors.affiliation: Servizio di Medicina Trasfusionale, Dept. Ematologia e Medicina Trasfusionale, Azienda Ospedaliera SS Antonio e Biagio e C. Arrigo, Alessandria, Italy. pborzini@ospedale.al.it
authors.forename: Piero
authors.initials: P
authors.lastname: Borzini
authors.forename: Laura
authors.initials: L
authors.lastname: Mazzucco
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000378:metabolism / Q000502:physiology*; D001793:Blood Preservation; D048091:Guided Tissue Regeneration / Q000379:methods; D006801:Humans; D044968:Regenerative Medicine / Q000379:methods*