title: Gentamicin supplemented polyvinylidenfluoride mesh materials enhance tissue integration due to a transcriptionally reduced MMP-2 protein expression.
abstract: BACKGROUND
  A beneficial effect of gentamicin supplemented mesh material on tissue integration is known. To further elucidate the interaction of collagen and MMP-2 in chronic foreign body reaction and to determine the significance of the MMP-2-specific regulatory element (RE-1) that is known to mediate 80% of the MMP-2 promoter activity, the spatial and temporal transcriptional regulation of the MMP-2 gene was analyzed at the cellular level.
  
  
  METHODS
  A PVDF mesh material was surface modified by plasma-induced graft polymerization of acrylic acid (PVDF+PAAc). Three different gentamicin concentrations were bound to the provided active sites of the grafted mesh surfaces (2, 5 and 8 μg/mg). 75 male transgenic MMP-2/LacZ mice harbouring the LacZ reporter gene under control of MMP-2 regulatory sequence -1241/+423, excluding the RE-1 were randomized to five groups. Bilateral of the abdominal midline one of the five different meshes was implanted subcutaneously in each animal. MMP-2 gene transcription (anti-ß-galactosidase staining) and MMP-2 protein expression (anti-MMP-2 staining) were analyzed semiquantitatively by immunohistochemistry 7, 21 and 90 days after mesh implantation. The collagen type I/III ratio was analyzed by cross polarization microscopy to determine the quality of mesh integration.
  
  
  RESULTS
  The perifilamentary ß-galactosidase expression as well as the collagen type I/III ratio increased up to the 90th day for all mesh modifications, whereas no significant changes could be observed for MMP-2 protein expression between days 21 and 90. Both the 5 and 8 μg/mg gentamicin group showed significantly reduced levels of ß-galactosidase expression and MMP-2 positive stained cells when compared to the PVDF group on day 7, 21 and 90 respectively (5 μg/mg: p < 0.05 each; 8 μg/mg: p < 0.05 each). Though the type I/III collagen ratio increased over time for all mesh modifications significant differences to the PVDF mesh were only detected for the 8 μg/mg group at all 3 time points (p < 0.05 each).
  
  
  CONCLUSIONS
  Our current data indicate that lack of RE-1 is correlated with increased mesh induced MMP-2-gene expression for coated as well as for non-coated mesh materials. Gentamicin coating reduced MMP-2 transcription and protein expression. For the 8 μg/mg group this effect is associated with an increased type I/III collagen ratio. These findings suggest that gentamicin is beneficial for tissue integration after mesh implantation, which possibly is mediated via RE-1.
authors.affiliation: Department of General, Visceral and Transplantation Surgery, RWTH Aachen University Hospital, Aachen, Germany. mbinneboesel@ukaachen.de
authors.forename: Marcel
authors.initials: M
authors.lastname: Binnebösel
authors.forename: Klaus T
authors.initials: KT
authors.lastname: von Trotha
authors.forename: Christina
authors.initials: C
authors.lastname: Ricken
authors.forename: Christian D
authors.initials: CD
authors.lastname: Klink
authors.forename: Karsten
authors.initials: K
authors.lastname: Junge
authors.forename: Joachim
authors.initials: J
authors.lastname: Conze
authors.forename: Marc
authors.initials: M
authors.lastname: Jansen
authors.forename: Ulf P
authors.initials: UP
authors.lastname: Neumann
authors.forename: Petra
authors.initials: P
authors.lastname: Lynen Jansen
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D005549:Foreign-Body Reaction / Q000378:metabolism; D005839:Gentamicins / Q000008:administration & dosage / Q000494:pharmacology*; D007763:Lac Operon; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D008567:Membranes, Artificial; D051379:Mice; D008822:Mice, Transgenic; D011145:Polyvinyls; D011500:Protein Synthesis Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D012097:Repressor Proteins / Q000378:metabolism; D013526:Surgical Mesh; D014158:Transcription, Genetic / Q000187:drug effects*; D014945:Wound Healing / Q000187:drug effects*; D001616:beta-Galactosidase / Q000378:metabolism; D000099229:RE1-Silencing Transcription Factor; D005465:Fluorocarbon Polymers
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D005839:Gentamicins; D020778:Matrix Metalloproteinase 2; D008567:Membranes, Artificial; D011145:Polyvinyls; D011500:Protein Synthesis Inhibitors; D012097:Repressor Proteins; D001616:beta-Galactosidase; D000099229:RE1-Silencing Transcription Factor; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers