title: Topical application of hPDGF-A-modified porcine BMSC and keratinocytes loaded on acellular HAM promotes the healing of combined radiation-wound skin injury in minipigs.
abstract: OBJECTIVE
  To evaluate the efficacy of cultured cutaneous substitute (CCS) in accelerating the healing of combined radiation-skin wound injury (CRWI) in minipigs.
  
  
  METHODS
  Autologous porcine bone marrow-derived mesenchymal stem cells (BMSC) and skin-derived keratinocytes (SK) were infected by recombinant retrovirus expressing human (h) platelet-derived growth factor-A (hPDGF-A). CCS was constructed by loading acellular human amniotic membrane (HAM) with normal porcine BMSC and SK (BMSC-/SK-CCS) or with hPDGF-A modified counterparts (BMSC+/SK+CCS). The expression of exogenous hPDGF-A in cells and CCS was assessed by reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). The CCS or HAM were grafted to the dorsal CRWI sites (20 Gy local irradiation plus full-thickness skin removal, diameter = 40 mm) of minipigs. Wound healing rate and pathological changes were observed.
  
  
  RESULTS
  High levels of hPDGF-A expression were confirmed in gene-modified cells (3780 pg/ml), cultured CCS (506 pg/ml) and transplanted CCS (250 pg/ml). The transplantation of the BMSC+/SK+CCS resulted in a shorter healing time (16-18, days) (P < 0.05 vs. other groups). The healing rates ranked as BMSC+/SK+CCS > BMSC-/SK-CCS > HAM > wound control. Pathologically, there were better granulation formation and re-epithelialisation, and collagen deposition in BMSC+/SK+CCS-treated wound than those in other groups. The angiogenesis ability followed the same order as healing rate of different groups. At day 7, the area densities of vasculature in granulation tissue of group BMSC+/SK+CCS, BMSC-/SK-CCS, HAM, wound only were 15.4, 10.3, 6.0 and 5.7%, respectively, while the number densities of vasculature was 767, 691, 126 and 109 (number/mm(2)), respectively.
  
  
  CONCLUSIONS
  Topical transplantation of hPDGF-A modified CCS may be applicable to the management of refractory wounds.
authors.affiliation: Institute of Combined Injuries, The State Key Laboratory of Trauma, Burns and Combined Injury, College of Preventive Medicine, Third Military Medical University, Chongqing.
authors.forename: Guohe
authors.initials: G
authors.lastname: Yan
authors.forename: Huiqin
authors.initials: H
authors.lastname: Sun
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Junping
authors.initials: J
authors.lastname: Wang
authors.forename: Fengchao
authors.initials: F
authors.lastname: Wang
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Zou
authors.forename: Tianmin
authors.initials: T
authors.lastname: Cheng
authors.forename: Guoping
authors.initials: G
authors.lastname: Ai
authors.forename: Yongping
authors.initials: Y
authors.lastname: Su
mesh_terms: D000287:Administration, Topical; D000650:Amnion / Q000196:embryology; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D015603:Keratinocytes / Q000166:cytology*; D010982:Platelet-Derived Growth Factor / Q000008:administration & dosage*; D011832:Radiation Injuries / Q000188:drug therapy*; D012190:Retroviridae / Q000235:genetics; D012867:Skin / Q000187:drug effects / Q000528:radiation effects*; D016038:Skin Transplantation; D017768:Skin, Artificial; D013234:Stem Cells / Q000166:cytology*; D013552:Swine; D014945:Wound Healing
chemical_list: D010982:Platelet-Derived Growth Factor