title: Bone Marrow-Derived Mesenchymal Stem Cells Enhance Bacterial Clearance and Preserve Bioprosthetic Integrity in a Model of Mesh Infection.
abstract: BACKGROUND
  The reported incidence of mesh infection in contaminated operative fields is as high as 30% regardless of the material used. Recently, mesenchymal stem cells (MSCs) have been shown to possess favorable immunomodulatory properties and improve tissue incorporation when seeded onto bioprosthetics. The aim of this study was to evaluate whether seeding noncrosslinked bovine pericardium (Veritas Collagen Matrix) with allogeneic bone marrow-derived MSCs improves infection resistance in vivo after inoculation with Escherichia coli (E. coli).
  
  
  METHODS
  Rat bone marrow-derived MSCs at passage 3 were seeded onto bovine pericardium and cultured for 7 days before implantation. Additional rats (n = 24) were implanted subcutaneously with MSC-seeded or unseeded mesh and inoculated with 7 × 10(5) colony-forming units of E. coli or saline before wound closure (group 1, unseeded mesh/saline; group 2, unseeded mesh/E. coli; group 3, MSC-seeded mesh/E. coli; 8 rats per group). Meshes were explanted at 4 weeks and underwent microbiologic and histologic analyses.
  
  
  RESULTS
  MSC-seeded meshes inoculated with E. coli demonstrated superior bacterial clearance and preservation of mesh integrity compared with E. coli-inoculated unseeded meshes (87.5% versus 0% clearance; p = 0.001). Complete mesh degradation concurrent with abscess formation was observed in 100% of rats in the unseeded/E. coli group, which is in contrast to 12.5% of rats in the MSC-seeded/E. coli group. Histologic evaluation determined that remodeling characteristics of E. coli-inoculated MSC-seeded meshes were similar to those of uninfected meshes 4 weeks after implantation.
  
  
  CONCLUSIONS
  Augmenting a bioprosthetic material with stem cells seems to markedly enhance resistance to bacterial infection in vivo and preserve mesh integrity.
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Erik T
authors.initials: ET
authors.lastname: Criman
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Wendy E
authors.initials: WE
authors.lastname: Kurata
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Karen W
authors.initials: KW
authors.lastname: Matsumoto
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Harry T
authors.initials: HT
authors.lastname: Aubin
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Carmen E
authors.initials: CE
authors.lastname: Campbell
authors.affiliation: Departments of General Surgery and Clinical Investigation, Tripler Army Medical Center, Honolulu, HI.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Pierce