title: Injectable gel graft for bone defect repair.
abstract: OBJECTIVE
  To examine the performance of an injectable gel graft made of transglutaminase (Tg)-crosslinked gelatin gel with BMP-2 (BMP-2-Tg-Gel) for bone defect repair in animal models.
  
  
  METHODS
  BMP-2 mixed with gelatin gel was crosslinked using Tg. The release of tethered BMP-2 through autocrine and paracrine pathways was demonstrated by using C2C12 and NIH 3T3 cells, respectively. BMP-2-Tg-Gel was injected into the induced cranial defect site. After 14 days, the sample was removed for x-ray imaging and histological evaluation.
  
  
  RESULTS
  Our in vivo results demonstrated that the injectable Tg-Gel with its osteoconductivity and controllable BMP-2 activity induced bone formation in our rat models when tethered with BMP-2.
  
  
  CONCLUSIONS
  Tg-Gel as an injectable functional bone graft may enable the use of minimally invasive surgical procedures to treat irregular-shaped bone defects. Furthermore, this novel approach is capable of incorporating and controlling the release of therapeutic agents that may advance the science of tissue regeneration.
authors.affiliation: Division of Plastic & Reconstructive Surgery, Department of Surgery, Keck Medical School, University of Southern California, 1333 San Pablo St, BMT 302A, Los Angeles, CA 90089-9112, USA.
authors.forename: Josephine
authors.initials: J
authors.lastname: Fang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yang
authors.forename: ShihJye
authors.initials: S
authors.lastname: Tan
authors.forename: Charisse
authors.initials: C
authors.lastname: Tayag
authors.forename: Marcel E
authors.initials: ME
authors.lastname: Nimni
authors.forename: Mark
authors.initials: M
authors.lastname: Urata
authors.forename: Bo
authors.initials: B
authors.lastname: Han
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism*; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology*; D016025:Bone Transplantation / Q000379:methods*; D005782:Gels / Q000008:administration & dosage / Q000627:therapeutic use*; D007267:Injections / Q000379:methods; D051379:Mice; D041681:NIH 3T3 Cells; D051381:Rats; D012886:Skull / Q000473:pathology*
chemical_list: C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D005782:Gels