title: Platelet-rich plasma affects bacterial growth in vitro.
abstract: OBJECTIVE
  Platelet-rich plasma (PRP), a blood derivative rich in platelets, is a relatively new technique used in tissue regeneration and engineering. The increased quantity of platelets makes this formulation of considerable value for their role in tissue healing and microbicidal activity. This activity was investigated against five of the most important strains involved in nosocomial infections (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and Streptococcus faecalis) to understand the prophylactic role of pure (P)-PRP. Microbicidal proteins released from activated P-PRP platelets were also determined.
  
  
  METHODS
  The microbicidal activity of P-PRP and platelet-poor plasma (PPP) was evaluated on different concentrations of the five bacterial strains incubated for 1, 2, 4 and 18 h and plated on agar for 18-24 h. P-PRP and PPP-released microbicidal proteins were evaluated by means of multiplex bead-based immunoassays.
  
  
  RESULTS
  P-PRP and PPP inhibited bacterial growth for up to 2 h of incubation. The effect of P-PRP was significantly higher than that of PPP, mainly at the low seeding concentrations and/or shorter incubation times, depending on the bacterial strain. Chemokine (C-C motif) ligand-3, chemokine (C-C motif) ligand-5 and chemokine (C-X-C motif) ligand-1 were the molecules mostly related to Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus faecalis inhibition. Escherichia coli and Klebsiella pneumoniae were less influenced.
  
  
  CONCLUSIONS
  The present results show that P-PRP might supply an early protection against bacterial contaminations during surgical interventions because the inhibitory activity is already evident from the first hour of treatment, which suggests that physiological molecules supplied in loco might be important in the time frame needed for the activation of the innate immune response.
authors.affiliation: Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopaedic Institute, Bologna, Italy; Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy. Electronic address: erminia.mariani@unibo.it.
authors.forename: Erminia
authors.initials: E
authors.lastname: Mariani
authors.affiliation: Laboratory of Biomechanics and Technology Innovation/NABI, 2nd Orthopaedic and Traumatologic Clinic, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.affiliation: Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Canella
authors.affiliation: Operative Unit of Clinical Microbiology, St. Orsola-Malpighi University Hospital, Regional Reference Centre for Microbiological Emergencies, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Berlingeri
authors.affiliation: Operative Unit of Clinical Microbiology, St. Orsola-Malpighi University Hospital, Regional Reference Centre for Microbiological Emergencies, Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bielli
authors.affiliation: Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Cattini
authors.affiliation: Operative Unit of Clinical Microbiology, St. Orsola-Malpighi University Hospital, Regional Reference Centre for Microbiological Emergencies, Bologna, Italy.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Landini
authors.affiliation: Laboratory of Biomechanics and Technology Innovation/NABI, 2nd Orthopaedic and Traumatologic Clinic, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Kon
authors.affiliation: Laboratory of Biomechanics and Technology Innovation/NABI, 2nd Orthopaedic and Traumatologic Clinic, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
authors.affiliation: Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopaedic Institute, Bologna, Italy; Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Facchini
mesh_terms: D000328:Adult; D000891:Anti-Infective Agents, Local / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D001424:Bacterial Infections / Q000209:etiology / Q000517:prevention & control*; D048708:Cell Growth Processes / Q000187:drug effects; D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism; D048091:Guided Tissue Regeneration; D006801:Humans; D008297:Male; D053657:Platelet-Rich Plasma / Q000378:metabolism* / Q000382:microbiology; D013514:Surgical Procedures, Operative; D013530:Surgical Wound Infection / Q000209:etiology / Q000517:prevention & control*; D023822:Tissue Engineering
chemical_list: D000891:Anti-Infective Agents, Local; D018925:Chemokines
keywords: bacterial growth; kinocidins; microbicidal activity; microbicidal proteins; nosocomial infections; platelet-rich plasma