title: The effects of polydeoxyribonucleotide on the survival of random pattern skin flaps in rats.
abstract: BACKGROUND
  Partial or complete necrosis of a skin flap is a common problem. Polydeoxyribonucleotide (PDRN) can be extracted from trout sperm and used as a tissue repair agent. The aim of this study was to investigate whether PDRN could improve the survival of random pattern skin flaps in rats.
  
  
  METHODS
  Twenty-two male Sprague-Dawley rats were randomly divided into two groups: the PDRN treatment group (n=11) and the control group (n=11). Caudally pedicled random pattern skin flaps were elevated on their dorsal skin and resutured. The treatment group received daily intraperitoneal administration of PDRN (8 mg/kg/day), and the control group received fluid vehicle (NaCl 0.9%, 8 mg/kg/day) from day 0 to day 6. On day 7, the flap survival was evaluated and the harvested tissue surrounding the demarcation line of the necrotic area was stained with H&E, anti-rat vascular endothelial cell growth factor (VEGF) antibody, and PECAM-1/CD31 antibody.
  
  
  RESULTS
  The average necrotic area of the flap in the PDRN group was significantly smaller when compared with that of the control group. Histologic and immunohistochemical evaluation showed that granulation thickness score and VEGF-positive staining cells were marked higher in the PDRN group than in the control group. PECAM-1/CD31-positive microvascular densities were significantly higher in the PDRN group when compared with the control group.
  
  
  CONCLUSIONS
  This study confirms that PDRN improves the survival of random pattern skin flaps in rats. These results may represent a new therapeutic approach to enhancing flap viability and achieving faster wound repair.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Kun Il
authors.initials: KI
authors.lastname: Chung
authors.forename: Han Koo
authors.initials: HK
authors.lastname: Kim
authors.forename: Woo Seob
authors.initials: WS
authors.lastname: Kim
authors.forename: Tae Hui
authors.initials: TH
authors.lastname: Bae
keywords: Angiogenesis modulating agents; Antigens, CD31; Polydeoxyribonucleotides; Surgical flaps; Vascular endothelial growth factors