title: Development of novel electrospun absorbable polycaprolactone (PCL) scaffolds for hernia repair applications.
abstract: BACKGROUND
  Permanent/nonresorbable hernia repair materials rely on profibrotic wound healing, and repair sites are commonly composed of disorganized tissue with inferior mechanical strength and risk of reherniation. Resorbable electrospun scaffolds represent a novel class of biomaterials, which may provide a unique platform for the design of advanced soft tissue repair materials. These materials are simple, inexpensive, nonwoven materials composed of polymer fibers that readily mimic the natural extracellular matrix. The primary goal of the present study was to evaluate the physiomechanical properties of novel electrospun scaffolds to determine their suitability for hernia repair. Based on previous experimentation, scaffolds possessing ≥ 20 N suture retention strength, ≥ 20 N tear resistance, and ≥ 50 N/cm tensile strength are appropriate for hernia repair.
  
  
  METHODS
  Six novel electrospun scaffolds were fabricated by varying combinations of polymer concentration (10-12 %) and flow rate (3.5-10 mL/h). Briefly, poly(ε-caprolactone) (PCL) was dissolved in a solvent mixture and electrospun onto a planar metal collector, yielding sheets with randomly oriented fibers. Physiomechanical properties were evaluated through scanning electron microscopy, laser micrometry, and mechanical testing.
  
  
  RESULTS
  Scanning electron micrographs demonstrated fiber diameters ranging from 1.0 ± 0.1 μm (10 % PCL, 3.5 mL/h) to 1.5 ± 0.2 μm (12 % PCL, 4 mL/h). Laser micrometry demonstrated thicknesses ranging from 0.72 ± 0.07 mm (12 % PCL, 10 mL/h) to 0.91 ± 0.05 mm (10 % PCL, 3.5 mL/h). Mechanical testing identified two scaffolds possessing suture retention strengths ≥ 20 N (12 % PCL, 10 mL/h and 12 % PCL, 6 mL/h), and no scaffolds possessing tear resistance values ≥ 20 N (range, 4.7 ± 0.9 N to 10.6 ± 1.8 N). Tensile strengths ranged from 35.27 ± 2.08 N/cm (10 % PCL, 3.5 mL/h) to 81.76 ± 15.85 N/cm (12 % PCL, 4 mL/h), with three scaffolds possessing strengths ≥ 50 N/cm (12 % PCL, 10 mL/h; 12 % PCL, 6 mL/h; 12 % PCL, 4 mL/h).
  
  
  CONCLUSIONS
  Two electrospun scaffolds (12 % PCL, 10 mL/h and 12 % PCL, 6 mL/h) possessed suture retention and tensile strengths appropriate for hernia repair, justifying evaluation in a large animal model. Additional studies examining advanced methods of fabrication may further improve the unique properties of these scaffolds, propelling them into applications in a variety of clinical settings.
authors.affiliation: Section of Minimally Invasive Surgery, Department of Surgery, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8109, St. Louis, MO 63110, USA.
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Ebersole
authors.forename: Evan G
authors.initials: EG
authors.lastname: Buettmann
authors.forename: Matthew R
authors.initials: MR
authors.lastname: MacEwan
authors.forename: Michael E
authors.initials: ME
authors.lastname: Tang
authors.forename: Margaret M
authors.initials: MM
authors.lastname: Frisella
authors.forename: Brent D
authors.initials: BD
authors.lastname: Matthews
authors.forename: Corey R
authors.initials: CR
authors.lastname: Deeken
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials; D059685:Herniorrhaphy / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D011091:Polyesters; D013314:Stress, Mechanical; D013526:Surgical Mesh; D013537:Sutures; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C016240:polycaprolactone