title: Efficacy of freeze-dried platelet-rich plasma in bone engineering.
abstract: OBJECTIVE
  Platelet-rich plasma (PRP) is typically isolated and applied immediately after preparation, making it both a time- and labor-intensive addition to the operative procedure. Thus, it would be convenient if PRP could be preserved. We evaluated the efficacy of freeze-dried PRP (FD-PRP), as compared with freshly isolated PRP (f-PRP) for bone engineering.
  
  
  METHODS
  FD-PRP was prepared by lyophilization of f-PRP and was subsequently preserved at -20°C for one month. It was then rehydrated with an equal or 1/3 amount of distilled water (×1FD-PRP, ×3FD-PRP, respectively), and we assessed its gelation properties and the release of growth factors (PDGF-BB, TGF-β1, and VEGF). We also examined the bone forming ability with onlay-grafting on mice calvaria using β-TCP granules as a scaffold.
  
  
  RESULTS
  FD-PRP showed comparable gelation as f-PRP. In terms of growth factor release,×1FD-PRP released identical concentrations of PDGF-BB and TGF-β1 to f-PRP, while ×3FD-PRP released approximately 3-fold concentrations when compared with f-PRP. In vivo, ×1FD-PRP promoted identical levels of the bone formation as f-PRP, and ×3FD-PRP induced more abundant bone formation.
  
  
  CONCLUSIONS
  These results suggest that f-PRP can be stored without functional loss by freeze-drying and the concentration of PRP may improve its efficacy in bone engineering.
authors: Department of Regenerative Oral Surgery, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki-shi, Nagasaki 852-8102, Japan.
authors: Yuya
authors: Y
authors: Nakatani
authors: Department of Regenerative Oral Surgery, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki-shi, Nagasaki 852-8102, Japan.
authors: Hideki
authors: H
authors: Agata
authors: Department of Regenerative Oral Surgery, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki-shi, Nagasaki 852-8102, Japan.
authors: Yoshinori
authors: Y
authors: Sumita
authors: Department of Regenerative Oral Surgery, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki-shi, Nagasaki 852-8102, Japan.
authors: Takamitsu
authors: T
authors: Koga
authors: Department of Regenerative Oral Surgery, Unit of Translational Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki-shi, Nagasaki 852-8102, Japan. Electronic address: asahina@nagasaki-u.ac.jp.
authors: Izumi
authors: I
authors: Asahina
mesh_terms: D000818:Animals; D000077214:Becaplermin; D001793:Blood Preservation / Q000379:methods*; D002130:Calcium Phosphates / Q000494:pharmacology; D005612:Freeze Drying / Q000379:methods*; D006801:Humans; D016867:Immunocompromised Host; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D023421:Models, Animal; D010012:Osteogenesis; D053657:Platelet-Rich Plasma / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis / Q000378:metabolism; D012886:Skull / Q000166:cytology / Q000637:transplantation; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D002130:Calcium Phosphates; D036341:Intercellular Signaling Peptides and Proteins; D020574:Proto-Oncogene Proteins c-sis; C485817:beta-tricalcium phosphate; D000077214:Becaplermin
keywords: Bone regeneration; Freeze-Dry; Long storage; Platelet-rich plasma; Super-concentrated platelets