title: Tissue regeneration and in loco administration of platelet derivatives: clinical outcome, heterogeneous products, and heterogeneity of the effector mechanisms.
abstract: BACKGROUND
  In loco administration of platelet (PLT) derivatives is a relatively new auxiliary treatment for tissue regeneration to be hastened. Enthusiastic reports are faced by more critical ones. The more obvious rationale for the in vivo administration of PLT derivatives resides in their growth factor content.
  
  
  METHODS
  The relevant literature was systematically reviewed. Close scrutiny of the technical details was carried out to find out the procedural differences accounting for conflicting results.
  
  
  RESULTS
  An impressively vast heterogeneity of conduct was found in both in vitro and in vivo studies. Major outcome-affecting variables were recognized such as those associated with PLT preparation; growth factor measurement; proliferation test; dose, timing, and administration of the PLT derivatives; study design; and primary endpoints.
  
  
  CONCLUSIONS
  So many variables were found making standardization or confrontation of the in vitro and the in vivo studies barely conceivable or manageable. The mechanisms of action are very complex. The attribution of tissue regeneration capacity of PLT derivatives solely to the PLT-derived growth factors is simplistic. The results obtained through in vitro experiments are indicative for general mechanisms. Their simplistic hold to the complex in vivo environment may be misleading.
authors.affiliation: Department of Hematology and Transfusion Medicine, Transfusion Medicine Service, SS Antonio and Biagio Hospital, 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; D001803:Blood Transfusion; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D010949:Plasma; D017713:Platelet Transfusion; D010982:Platelet-Derived Growth Factor / Q000627:therapeutic use*; D023822:Tissue Engineering / Q000379:methods; D016896:Treatment Outcome
chemical_list: D010982:Platelet-Derived Growth Factor