title: Commercial extracellular matrix scaffolds for rotator cuff tendon repair. Biomechanical, biochemical, and cellular properties.
abstract: BACKGROUND
  We are not aware of any in vitro study comparing the biomechanical, biochemical, and cellular properties of commercial extracellular matrix materials marketed for rotator cuff tendon repair. In this study, the properties of GraftJacket, TissueMend, Restore, and CuffPatch were quantified and compared with each other. The elastic moduli were also compared with that of normal canine infraspinatus tendon.
  
  
  METHODS
  Samples were tested from different manufacturing lots of four materials: GraftJacket (ten lots), TissueMend (six), Restore (ten), and CuffPatch (six). The Kruskal-Wallis test was used to compare thickness, stiffness, and modulus as well as hydroxyproline, chondroitin/dermatan sulfate glycosaminoglycan, hyaluronan, and DNA contents among these matrices. The moduli of the extracellular matrices were also compared with those of normal canine infraspinatus tendon.
  
  
  RESULTS
  All four extracellular matrices required 10% to 30% stretch before they began to carry substantial load. Their maximum moduli were realized in their linear region at 30% to 80% strain. The elastic moduli of all four commercial matrices were an order of magnitude lower than that of canine infraspinatus tendon. TissueMend had significantly higher DNA content than the other three matrices (p<0.0001), although both Restore and GraftJacket also had measurable amounts of DNA.
  
  
  CONCLUSIONS
  Our data demonstrate chemical and mechanical differences among the four commercial extracellular matrices that we evaluated. Probably, the source (dermis or small intestine submucosa), species (human, porcine, or bovine), age of the donor (fetal or adult), and processing of these matrices all contribute to the unique biophysical properties of the delivered product. The biochemical composition of commercial extracellular matrices is similar to that of tendon. However, the elastic moduli of these materials are an order of magnitude lower than that of tendon, suggesting a limited mechanical role in augmentation of tendon repair.
authors.affiliation: Department of Biomedical Engineering, ND-20, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. derwink@ccf.org
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Derwin
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Baker
authors.forename: Rebecca K
authors.initials: RK
authors.lastname: Spragg
authors.forename: Diane R
authors.initials: DR
authors.lastname: Leigh
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Iannotti
mesh_terms: D000818:Animals; D001178:Arthroplasty; D001672:Biocompatible Materials; D001696:Biomechanical Phenomena; D002807:Chondroitin / Q000032:analysis; D003094:Collagen / Q000627:therapeutic use; D003871:Dermatan Sulfate / Q000032:analysis; D004548:Elasticity; D005109:Extracellular Matrix; D006801:Humans; D006820:Hyaluronic Acid / Q000032:analysis; D006909:Hydroxyproline / Q000032:analysis; D007413:Intestinal Mucosa / Q000637:transplantation; D008422:Materials Testing; D019637:Orthopedic Procedures; D019736:Prostheses and Implants; D000070636:Rotator Cuff Injuries; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; C422414:Permacol; D003871:Dermatan Sulfate; D006820:Hyaluronic Acid; D002807:Chondroitin; D003094:Collagen; D006909:Hydroxyproline