title: Low-intensity pulsed ultrasound prompts tissue-engineered bone formation after implantation surgery.
abstract: BACKGROUND
  A practical problem impeding clinical translation is the limited bone formation seen in artificial bone grafts. Low-pressure/vacuum seeding and dynamic culturing in bioreactors have led to a greater penetration into the scaffolds, enhanced production of bone marrow cells, and improved tissue-engineered bone formation. The goal of this study was to promote more extensive bone formation in the composites of porous ceramics and bone marrow stromal cells (BMSCs).
  
  
  METHODS
  BMSCs/β-tricalcium phosphate (β-TCP) composites were subcultured for 2 weeks and then subcutaneously implanted into syngeneic rats that were split into a low-intensity pulsed ultrasound (LIPUS) treatment group and a control group. These implants were harvested at 5, 10, 25, and 50 days after implantation. The samples were then biomechanically tested and analyzed for alkaline phosphate (ALP) activity and osteocalcin (OCN) content and were also observed by light microscopy.
  
  
  RESULTS
  The levels of ALP activity and OCN content in the composites were significantly higher in the LIPUS group than in the control group. Histomorphometric analysis revealed a greater degree of soft tissue repair, increased blood flow, better angiogenesis, and more extensive bone formation in the LIPUS groups than in the controls. No significant difference in the compressive strength was found between the two groups.
  
  
  CONCLUSIONS
  LIPUS treatment appears to enhance bone formation and angiogenesis in the BMSCs/β-TCP composites.
authors.affiliation: Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
authors.forename: Juyong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, First Hospital of China Medical University, Shenyang, Liaoning 110001, China.
authors.forename: Juqiang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 1138519, Japan.
authors.forename: Asou
authors.initials: A
authors.lastname: Yoshinori
authors.affiliation: Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: Fu
authors.initials: F
authors.lastname: Paul
authors.affiliation: Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China. Email: wangjywh@yahoo.com.
authors.forename: Huiliang
authors.initials: H
authors.lastname: Shen
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 1138519, Japan.
authors.forename: Jiani
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 1138519, Japan; COE Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 1138519, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sotome
authors.affiliation: Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Surgery, Graduate School, Tokyo Medical and Dental University, Tokyo 1138519, Japan; COE Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 1138519, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Shinomiya
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology; D016025:Bone Transplantation; D002130:Calcium Phosphates / Q000494:pharmacology; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D017154:Stromal Cells; D023822:Tissue Engineering / Q000379:methods*; D014185:Transplantation, Isogeneic; D014465:Ultrasonics / Q000379:methods*
chemical_list: D002130:Calcium Phosphates; C018392:tricalcium phosphate