title: Platelet-rich fibrin prepared from stored whole-blood samples.
abstract: BACKGROUND
  In regenerative therapy, self-clotted platelet concentrates, such as platelet-rich fibrin (PRF), are generally prepared on-site and are immediately used for treatment. If blood samples or prepared clots can be preserved for several days, their clinical applicability will expand. Here, we prepared PRF from stored whole-blood samples and examined their characteristics.
  
  
  METHODS
  Blood samples were collected from non-smoking, healthy male donors (aged 27-67 years, N = 6), and PRF clots were prepared immediately or after storage for 1-2 days. Fibrin fiber was examined by scanning electron microscopy. Bioactivity was evaluated by means of a bioassay system involving human periosteal cells, whereas PDGF-BB concentrations were determined by an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Addition of optimal amounts of a 10% CaCl2solution restored the coagulative ability of whole-blood samples that contained an anticoagulant (acid citrate dextrose) and were stored for up to 2 days at ambient temperature. In PRF clots prepared from the stored whole-blood samples, the thickness and cross-links of fibrin fibers were almost identical to those of freshly prepared PRF clots. PDGF-BB concentrations in the PRF extract were significantly lower in stored whole-blood samples than in fresh samples; however, both extracts had similar stimulatory effects on periosteal-cell proliferation.
  
  
  CONCLUSIONS
  Quality of PRF clots prepared from stored whole-blood samples is not reduced significantly and can be ensured for use in regenerative therapy. Therefore, the proposed method enables a more flexible treatment schedule and choice of a more suitable platelet concentrate immediately before treatment, not after blood collection.
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Kazushige
authors.initials: K
authors.lastname: Isobe
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kitamura
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Taiji
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Kawabata
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Okudera
authors.affiliation: Tokyo Plastic Dental Society, Kita-ku, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Okudera
authors.affiliation: Division of Oral Implantology, Niigata University Medical and Dental Hospital, Niigata, Japan.
authors.forename: Kohya
authors.initials: K
authors.lastname: Uematsu
authors.affiliation: Bioscience Medical Research Center, Niigata University Medical and Dental Hospital, Niigata, Japan.
authors.forename: Koh
authors.initials: K
authors.lastname: Nakata
authors.affiliation: Department of Materials Science and Technology, Niigata University, Niigata, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Division of Oral Bioengineering, Institute of Medicine and Dentistry, Niigata University, Niigata, Japan. kawase@dent.niigata-u.ac.jp.
authors.forename: Tomoyuki
authors.identifier: http://orcid.org/0000-0003-4160-396X
authors.initials: T
authors.lastname: Kawase
keywords: Anticoagulant; Calcium chloride; Coagulation; Fibrin fiber; Platelet-rich fibrin