title: Promoting spinal fusions by biomineralized silk fibroin films seeded with bone marrow stromal cells: An in vivo animal study.
abstract: OBJECTIVE
  To prepare a biomineralized nano silk fibroin film seeded with bone marrow stromal cells (BMSCs), and to evaluate its performance in spinal fusion.
  
  
  METHODS
  The silk fibroin film was mineralized in a modified, simulated body fluid, seeded with BMSCs, and evaluated in a rat model of posterolateral lumbar fusion, compared with pure silk fibroin, silk fibroin/bone marrow stromal cells, mineralized silk fibroin, mineralized silk fibroin/bone marrow stromal cells, iliac crest bone, and no graft. After 12 weeks, all rats were sacrificed and underwent manual palpation, micro-CT scanning, biomechanical testing, and histology.
  
  
  RESULTS
  The infrared spectrum, X-ray diffraction, and scanning electron microscopy demonstrated deposition of mineral layers on the silk fibroin film surface. The fusion rate, bone volume, relative strength and stiffness, and histological score of the mineralized silk fibroin/bone marrow stromal cells were slightly lower than the autograft, but without any significant difference (p > 0.05). In addition, the mineralized silk fibroin was significantly greater in most parameters than the silk fibroin/bone marrow stromal cells (p < 0.05).
  
  
  CONCLUSIONS
  The mineralized silk fibroin resembles natural bone structurally, and the cellular and mineral layers of silk fibroin are both critical to bone regeneration. The ability to promote spinal fusion is enhanced when the mineralized silk fibroin is seeded with bone marrow stromal cells.
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Gu
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, China chenliangsuzhou@126.com.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, China.
authors.forename: Hai-Yun
authors.initials: HY
authors.lastname: Niu
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, China.
authors.forename: Xiao-Feng
authors.initials: XF
authors.lastname: Shen
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, China.
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D012831:Bombyx / Q000737:chemistry; D001861:Bone Regeneration; D018786:Bone Substitutes / Q000737:chemistry*; D005349:Fibroins / Q000737:chemistry*; D008159:Lumbar Vertebrae / Q000473:pathology / Q000502:physiology / Q000601:surgery*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013123:Spinal Fusion / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D018786:Bone Substitutes; D005349:Fibroins
keywords: Biomimetic mineralization; bone formation; bone marrow stromal cells (BMSCs); silk fibroin; spinal fusion