title: Evaluation of a collagen-coated, resorbable fiber scaffold loaded with a peptide basic fibroblast growth factor mimetic in a sheep model of rotator cuff repair.
abstract: BACKGROUND
  A new scaffold design combined with a peptide growth factor was tested prospectively for safety and for improved tendon healing in sheep.
  
  
  METHODS
  The infraspinatus tendon was detached and then surgically repaired to the humerus using sutures and anchors in 50 adult sheep. The repairs in 40 of these sheep were reinforced with a scaffold containing F2A, a peptide mimetic of basic fibroblast growth factor. The sheep were examined after 8 or 26 weeks with magnetic resonance imaging, full necropsy, and histopathologic analysis. A second cohort of 30 sheep underwent surgical repair--20 with scaffolds containing F2A. The 30 shoulders were tested mechanically after 8 weeks.
  
  
  RESULTS
  The scaffold and F2A showed no toxicity. Scaffold-repaired tendons were 31% thicker than surgically repaired controls (P = .037) at 8 weeks. There was more new bone formed at the tendon footprint in sheep treated with F2A. Surgically repaired tendons delaminated from the humerus across 14% of the footprint area. The extent of delamination decreased to 1.3% with increasing doses of F2A (P = .004). More of the repair tissue at the footprint was tendon-like in the peptide-treated sheep. On mechanical testing, only 7 shoulders tore at the repair site. The repairs in the other 23 shoulders were already stronger than the midsubstance tendon at 8 weeks.
  
  
  CONCLUSIONS
  The new scaffold and peptide safely improved tendon healing.
authors.affiliation: DRP Biomedical, Carlsbad, CA, USA. Electronic address: 2dalesmail@gmail.com.
authors.forename: Dale R
authors.initials: DR
authors.lastname: Peterson
authors.affiliation: Microvascular Tissues, Boston, MA, USA.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Ohashi
authors.affiliation: Advanced Biological Concepts, Los Alamitos, CA, USA.
authors.forename: Harold M
authors.initials: HM
authors.lastname: Aberman
authors.affiliation: Golden Orthopedic, Delray Beach, FL, USA.
authors.forename: Pedro A
authors.initials: PA
authors.lastname: Piza
authors.affiliation: New West Sports Medicine, Kearney, NE, USA.
authors.forename: Heber C
authors.initials: HC
authors.lastname: Crockett
authors.affiliation: Miami Sports Medicine, Miami, FL, USA.
authors.forename: Joseph I
authors.initials: JI
authors.lastname: Fernandez
authors.affiliation: SimonMed Imaging, Scottsdale, AZ, USA.
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Lund
authors.affiliation: Experimental Pathology Laboratories, Sterling, VA, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Funk
authors.affiliation: Charter Preclinical Services, Hudson, MA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Hawes
authors.affiliation: Union Memorial Hospital, Baltimore, MD, USA.
authors.forename: Brent G
authors.initials: BG
authors.lastname: Parks
authors.affiliation: Microvascular Tissues, Boston, MA, USA.
authors.forename: Ralph-Heiko
authors.initials: RH
authors.lastname: Mattern
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001861:Bone Regeneration; D024042:Collagen Type I / Q000008:administration & dosage*; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D008279:Magnetic Resonance Imaging; D023421:Models, Animal; D011446:Prospective Studies; D012756:Sheep; D013710:Tendons / Q000473:pathology / Q000601:surgery*; D013718:Tensile Strength; D054457:Tissue Scaffolds
chemical_list: D024042:Collagen Type I; D016222:Fibroblast Growth Factor 2
keywords: Scaffold; bFGF; mimetic; peptide; poly-4-hydroxybutyrate; rotator cuff; sheep