title: [Three-dimensional structure of platelet-rich fibrin gel and its effect on proliferation of human dental pulp cells in vitro].
abstract: OBJECTIVE
  This study was designed to analyze the three-dimensional structure of platelet-rich fibrin (PRF) gel as scaffold for dental pulp regeneration, and to investigate the effect of PRF gel on the proliferation of human dental pulp cells (hDPCs) in vitro.
  
  
  METHODS
  PRF gel prepared by Choukroun's protocols was evaluated by light microscope and scanning electron microscope (SEM). The extract of PRF gel was collected at the time point of 7th day. The experimental group was divided into 2 subgroups (25% and 75%) according to the volume fraction of PRF gel extract. The 2 subgroups were named 1PRF and 3PRF, respectively. The hDPCs were isolated and cultured in DMEM with 1PRF and 3PRF, respectively. Cell proliferation was detected using cell counting kit-8 (CCK-8) at 24, 48, 72, 96, 120, 144 and 168 h, respectively. The data was analyzed with SPSS16.0 software package.
  
  
  RESULTS
  Platelet and leukocyte were mainly distributed at the junction between the red corpuscles and the PRF gel, which was called "buffy coat". "Buffy coat" was constructed by large and dense fibrin clusters. At 24, 48, 72 and 96 h, there was no significant difference (OD) value of optical density(OD) between experimental group and control group(P>0.05). At 120, 144 and 168 h, the OD value in the experimental group was significant higher than that of the control group (P<0.05); there was no significant difference of OD value between group 1PRF and 3PRF (P>0.05).
  
  
  CONCLUSIONS
  The results confirm that the three-dimensional structure of PRF gel is constituted by fibrin network. A large amount of platelet and leukocyte which can release high quantities of growth factors are concentrated in the PRF gel. The extract of PRF gel can accelerate the proliferation of hDPCs in time-dependent manner. PRF gel may be a proper scaffold for pulp regeneration. Supported by National Natural Science Foundation of China (81160133).
authors.affiliation: Department of Endodontics, College of Stomatology, Guangxi Medical University. Nanning 530021, Guangxi Zhuang Autonomous Region, China.E-mail:hexuan269@163.com.
authors.forename: Xuan
authors.initials: X
authors.lastname: He
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Wen-xia
authors.initials: WX
authors.lastname: Chen
mesh_terms: D001792:Blood Platelets; D049109:Cell Proliferation; D003782:Dental Pulp; D005337:Fibrin; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007962:Leukocytes; D012038:Regeneration
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D005337:Fibrin