title: Tissue-engineering with muscle fiber fragments improves the strength of a weak abdominal wall in rats.
abstract: OBJECTIVE
  Alternative approaches to reinforce the native tissue in patients with pelvic organ prolapse (POP) are needed to improve surgical outcome. Our aims were to develop a weakened abdominal wall in a rat model to mimic the weakened vaginal wall in women with POP and then evaluate the regenerative potential of a quickly biodegradable synthetic scaffold, methoxypolyethylene glycol polylactic-co-glycolic acid (MPEG-PLGA), seeded with autologous muscle fiber fragments (MFFs) using this model.
  
  
  METHODS
  In an initial pilot study with 15 animals, significant weakening of the abdominal wall and a feasible technique was established by creating a partial defect with removal of one abdominal muscle layer. Subsequently, 18 rats were evenly divided into three groups: (1) unrepaired partial defect; (2) partial defect repaired with MPEG-PLGA; (3) partial defect repaired with MPEG-PLGA and MFFs labeled with PKH26-fluorescence dye. After 8 weeks, we performed histopathological and immunohistochemical testing, fluorescence analysis, and uniaxial biomechanical testing.
  
  
  RESULTS
  Both macroscopically and microscopically, the MPEG-PLGA scaffold was fully degraded, with no signs of an inflammatory or foreign-body response. PKH26-positive cells were found in all animals from the group with added MFFs. Analysis of variance (ANOVA) showed a significant difference between groups with respect to load at failure (p = 0.028), and post hoc testing revealed that the group with MPEG-PLGA and MFFs showed a significantly higher strength than the group with MPEG-PLGA alone (p = 0.034).
  
  
  CONCLUSIONS
  Tissue-engineering with MFFs seeded on a scaffold of biodegradable MPEG-PLGA might be an interesting adjunct to future POP repair.
authors.affiliation: Department of Gynecology and Obstetrics, Copenhagen University Hospital Herlev, Herlev Ringvej 75, DK - 2730, Herlev, Denmark. hanna.jango@regionh.dk.
authors.forename: Hanna
authors.identifier: http://orcid.org/0000-0003-0224-1425
authors.initials: H
authors.lastname: Jangö
authors.affiliation: Department of Gynecology and Obstetrics, Copenhagen University Hospital Herlev, Herlev Ringvej 75, DK - 2730, Herlev, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Gräs
authors.affiliation: Department of Pathology, Copenhagen University Hospital Herlev, Herlev, Denmark.
authors.forename: Lise
authors.initials: L
authors.lastname: Christensen
authors.affiliation: Department of Gynecology and Obstetrics, Copenhagen University Hospital Herlev, Herlev Ringvej 75, DK - 2730, Herlev, Denmark.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lose
mesh_terms: D034861:Abdominal Wall / Q000601:surgery*; D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials; D004337:Drug Carriers; D005260:Female; D006801:Humans; D023421:Models, Animal; D018485:Muscle Fibers, Skeletal / Q000502:physiology*; D009930:Organic Chemicals; D056887:Pelvic Organ Prolapse / Q000601:surgery; D010865:Pilot Projects; D011092:Polyethylene Glycols; D011897:Random Allocation; D051381:Rats; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D009930:Organic Chemicals; C070080:PKH 26; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol
keywords: Autologous muscle fiber fragments; Biodegradable scaffold; Pelvic organ prolapse; Rats; Regenerative medicine; Tissue-engineering