title: The effect of locally delivered recombinant human bone morphogenetic protein-2 with hydroxyapatite/tri-calcium phosphate on the biomechanical properties of bone in diabetes-related osteoporosis.
abstract: BACKGROUND
  Recombinant human bone morphogenetic protein-2 (rhBMP-2) is particularly effective in improving osteogenesis in patients with diminished bone healing capabilities, such as individuals with type 1 diabetes mellitus (T1DM) who have impaired bone healing capabilities and increased risk of developing osteoporosis. This study measured the effects of rhBMP-2 treatment on osteogenesis by observing the dose-dependent effect of localized delivery of rhBMP-2 on biomechanical parameters of bone using a hydroxyapatite/tri-calcium phosphate (HA/TCP) carrier in a T1DM-related osteoporosis animal model.
  
  
  METHODS
  Two different doses of rhBMP-2 (LD low dose, HD high dose) with a HA/TCP carrier were injected into the femoral intramedullary canal of rats with T1DM-related osteoporosis. Two more diabetic rat groups were injected with saline alone and with HA/TCP carrier alone. Radiographs and micro-computed tomography were utilized for qualitative assessment of bone mineral density (BMD). Biomechanical testing occurred at 4- and 8-week time points; parameters tested included torque to failure, torsional rigidity, shear stress, and shear modulus.
  
  
  RESULTS
  At the 4-week time point, the LD and HD groups both exhibited significantly higher BMD than controls; at the 8-week time point, the HD group exhibited significantly higher BMD than controls. Biomechanical testing revealed dose-dependent, higher trends in all parameters tested at the 4- and 8-week time points, with minimal significant differences.
  
  
  CONCLUSIONS
  Groups treated with rhBMP-2 demonstrated improved bone mineral density at both 4 and 8 weeks compared to control saline groups, in addition to strong trends towards improvement of intrinsic and extrinsic biomechanical properties when compared to control groups. Data revealed trends toward dose-dependent increases in peak torque, torsional rigidity, shear stress, and shear modulus 4 weeks after rhBMP-2 treatment.
  
  
  METHODS
  Not applicable.
authors.affiliation: Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 E 17th Street, Suite 1402, New York, NY, 10003, USA, liporace33@gmail.com.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Liporace
authors.forename: Eric A
authors.initials: EA
authors.lastname: Breitbart
authors.forename: Richard S
authors.initials: RS
authors.lastname: Yoon
authors.forename: Erin
authors.initials: E
authors.lastname: Doyle
authors.forename: David N
authors.initials: DN
authors.lastname: Paglia
authors.forename: Sheldon
authors.initials: S
authors.lastname: Lin
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology*; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D004195:Disease Models, Animal; D017886:Durapatite / Q000494:pharmacology*; D005269:Femur / Q000473:pathology*; D008297:Male; D010012:Osteogenesis / Q000187:drug effects; D010024:Osteoporosis / Q000188:drug therapy* / Q000209:etiology*; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D055114:X-Ray Microtomography
chemical_list: D055396:Bone Morphogenetic Protein 2; D002130:Calcium Phosphates; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D017886:Durapatite; C020243:calcium phosphate