title: Developing Repair Materials for Stress Urinary Incontinence to Withstand Dynamic Distension.
abstract: BACKGROUND
  Polypropylene mesh used as a mid-urethral sling is associated with severe clinical complications in a significant minority of patients. Current in vitro mechanical testing shows that polypropylene responds inadequately to mechanical distension and is also poor at supporting cell proliferation.
  
  
  OBJECTIVE
  Our objective therefore is to produce materials with more appropriate mechanical properties for use as a sling material but which can also support cell integration.
  
  
  METHODS
  Scaffolds of two polyurethanes (PU), poly-L-lactic acid (PLA) and co-polymers of the two were produced by electrospinning. Mechanical properties of materials were assessed and compared to polypropylene. The interaction of adipose derived stem cells (ADSC) with the scaffolds was also assessed. Uniaxial tensiometry of scaffolds was performed before and after seven days of cyclical distension. Cell penetration (using DAPI and a fluorescent red cell tracker dye), viability (AlamarBlue assay) and total collagen production (Sirius red assay) were measured for ADSC cultured on scaffolds.
  
  
  RESULTS
  Polypropylene was stronger than polyurethanes and PLA. However, polypropylene mesh deformed plastically after 7 days of sustained cyclical distention, while polyurethanes maintained their elasticity. Scaffolds of PU containing PLA were weaker and stiffer than PU or polypropylene but were significantly better than PU scaffolds alone at supporting ADSC.
  
  
  CONCLUSIONS
  Therefore, prolonged mechanical distension in vitro causes polypropylene to fail. Materials with more appropriate mechanical properties for use as sling materials can be produced using PU. Combining PLA with PU greatly improves interaction of cells with this material.
authors.affiliation: Kroto research Institute, University of Sheffield, Broad Lane, Sheffield, United Kingdom.|Royal Hallamshire Hospital, Glossop Road, Sheffield, United Kingdom.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hillary
authors.affiliation: Kroto research Institute, University of Sheffield, Broad Lane, Sheffield, United Kingdom.
authors.forename: Sabiniano
authors.initials: S
authors.lastname: Roman
authors.affiliation: Kroto research Institute, University of Sheffield, Broad Lane, Sheffield, United Kingdom.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Bullock
authors.affiliation: Kroto research Institute, University of Sheffield, Broad Lane, Sheffield, United Kingdom.
authors.forename: Nicola H
authors.initials: NH
authors.lastname: Green
authors.affiliation: Royal Hallamshire Hospital, Glossop Road, Sheffield, United Kingdom.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Chapple
authors.affiliation: Kroto research Institute, University of Sheffield, Broad Lane, Sheffield, United Kingdom.
authors.forename: Sheila
authors.initials: S
authors.lastname: MacNeil
mesh_terms: D002478:Cells, Cultured; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D011126:Polypropylenes; D011140:Polyurethanes; D013526:Surgical Mesh; D054457:Tissue Scaffolds; D014550:Urinary Incontinence, Stress / Q000503:physiopathology / Q000601:surgery*
chemical_list: D011126:Polypropylenes; D011140:Polyurethanes