title: Favorable vocal fold wound healing induced by platelet-rich plasma injection.
abstract: OBJECTIVE
  To introduce a new injection material for vocal fold diseases, which could be readily translated to clinical practice, we investigated the effectiveness of platelet-rich plasma (PRP) injection on the injured vocal fold in terms of histological recovery.
  
  
  METHODS
  Blood samples were drawn from New Zealand White rabbits and PRP was isolated through centrifugation and separation of the samples. Using a CO2 laser, we made a linear wound in the 24 vocal fold sides of 12 rabbits and injected each wound with PRP on one vocal fold side and normal saline (NS) on the other. Morphologic analyses were conducted at 2, 4, and 12 weeks after injection, and inflammatory response, collagen deposit, and changes in growth factors were assessed using H&E and masson trichrome (MT) staining and western blot assay.
  
  
  RESULTS
  PRP was prepared in approximately 40 minutes. The mean platelet concentration was 1,315,000 platelets/mm(3). In morphological analyses, decreased granulation was observed in the PRP-injected vocal folds (P<0.05). However, the irregular surface and atrophic change were not difference. Histological findings revealed significant inflammation and collagen deposition in NS-injected vocal folds, whereas the PRP-injected vocal folds exhibited less (P<0.05). However, the inflammatory reaction and fibrosis were not difference. In western blot assay, increased amounts of growth factors were observed in PRP-injected vocal folds.
  
  
  CONCLUSIONS
  Injection of injured rabbit vocal folds with PRP led to improved wound healing and fewer signs of scarring as demonstrated by decreased inflammation and collagen deposition. The increased vocal fold regeneration may be due to the growth factors associated with PRP.
authors.affiliation: Department of Otolaryngology, Gyeongsang National University School of Medicine, Jinju, Korea. ; Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Woo
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Han-Sin
authors.initials: HS
authors.lastname: Jeong
authors.affiliation: Department of Otolaryngology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jin Pyeong
authors.initials: JP
authors.lastname: Kim
authors.affiliation: Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea. ; Department of Laboratory Medicine, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Eun-Ha
authors.initials: EH
authors.lastname: Koh
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seon Uk
authors.initials: SU
authors.lastname: Lee
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Jin
authors.affiliation: Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang Hyuk
authors.initials: SH
authors.lastname: Lee
keywords: Growth factor; Platelet-rich plasma; Scar; Vocal fold; Wound healing