title: Pressure ulcers: description of a new model and use of mesenchymal stem cells for repair.
abstract: BACKGROUND
  Pressure ulcers (PUs) still represent a heavy burden on many patients and nursing institutions. Our understanding of the pathophysiology and development of new treatments are hampered by the scarcity of suitable animal models.
  
  
  OBJECTIVE
  Evaluation of the translational value of an easily accessible mouse model.
  
  
  METHODS
  PUs were induced by application of magnetic devices on the dorsal skin of mice, which causes localized ischemia. The extent of the lesions and healing rate were quantified. Variations in ischemic exposure time were compared in hairless and normal mice. A detailed histological analysis of regeneration is presented. The influence of streptozotocin-induced diabetes, skin X-irradiation and treatment of the ulcers with human mesenchymal stem cells (MSCs) was investigated using immunodeficient NOD/SCID mice.
  
  
  RESULTS
  Ulcers induced by this form of ischemia have many features in common with decubitus ulcers in humans. No difference between hairy and hairless mice was observed in the rate of healing of the PUs. Unexpectedly, healing was not delayed in diabetic mice, but skin X-irradiation prior to ischemia resulted in a doubling of the time to complete closure of the PUs, and delayed repair of the dermis and panniculus carnosus muscle. Intradermal transplantation of human MSCs did not accelerate healing. The grafted MSCs were short-lived and only marginally participated in regeneration by differentiating into tissue-specific cells.
  
  
  CONCLUSIONS
  The results emphasize the difference in the characteristics of PUs as compared to surgical wounds. This experimental model is recommended for preclinical research on decubitus ulcers because of its mechanistic similarity with clinical PUs and its simplicity.
authors: Department of Molecular Cell Biology, Leiden University Medical Center, Einthovenweg 20, Leiden, The Netherlands. A.S.de_la_Garza @ lumc.nl
authors: Anabel S
authors: AS
authors: de la Garza-Rodea
authors: Shoshan
authors: S
authors: Knaän-Shanzer
authors: Dirk W
authors: DW
authors: van Bekkum
mesh_terms: D000328:Adult; D000818:Animals; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000628:therapy; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007511:Ischemia / Q000473:pathology; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D051379:Mice; D008812:Mice, Hairless; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D003668:Pressure Ulcer / Q000473:pathology / Q000628:therapy*; D014945:Wound Healing; D014965:X-Rays / Q000009:adverse effects