title: Combination of low-intensity pulsed ultrasound and C3H10T1/2 cells promotes bone-defect healing.
abstract: OBJECTIVE
  We systematically investigated the effect of combined use of low-intensity pulsed ultrasound (LIPUS) and bone mesenchymal stem cells C3H10T1/2 on bone-defect healing.
  
  
  METHODS
  C3H10T1/2 cells were first induced into a stationary phase by incubation with low fetal bovine serum (5 ml/l) for five days and then sonicated with LIPUS for ten minutes once every day for five consecutive days. The same LIPUS treatment combined with C3H10T1/2 cells, which were incubated in regular fetal bovine serum (10 ml/l) were used to aid femoral fracture healing in Sprague-Dawley rats during four consecutive weeks. C3H10T1/2 cell proliferation activity was detected by MTT assay. Cell-cycle changes were determined, and cell proliferation index was calculated using flow cytometry. Bone reparation was evaluated by X-ray imaging and hematoxylin and eosin (H&E) staining during the healing process.
  
  
  RESULTS
  LIPUS promoted C3H10T1/2 cell proliferation, the mechanism of which was possibly the up-regulation of Bmi-1 gene expression. At the end of week two after combined use of LIPUS and C3H10T1/2, the femoral gap was reduced on X-ray images. According to H&E staining results, new bone had homogeneous and similar density compared with normal surrounding bone after combined use of LIPUS and C3H10T1/2. At the end of week four, bone defects could not be observed by X-ray in all four groups and repaired bone substance in all four groups could be observed by H&E staining.
  
  
  CONCLUSIONS
  LIPUS treatment effectively promotes C3H10T1/2 cells to enter the growth/split phase from the stationary phase. This process enhances cell proliferation, which consequently promotes bone-defect healing.
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Ruixin
authors.initials: R
authors.lastname: He
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Weichen
authors.initials: W
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Haisheng
authors.initials: H
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Yueping
authors.initials: Y
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Baoru
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Ran
authors.affiliation: Department of Physics, University of Vermont, Burlington, VT, USA.
authors.forename: Junru
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China. wangyancqmu@163.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Ultrasound Engineering in Medicine Co-Founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Biomedical Engineering, College of Biomedical Engineering, Chongqing Medical University, No. 1 Yixueyuan Road, Chongqing, 400016, People's Republic of China. chenwz@haifu.com.cn.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Chen
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000166:cytology; D049109:Cell Proliferation / Q000235:genetics / Q000528:radiation effects; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology; D017102:Fracture Healing / Q000502:physiology*; D015870:Gene Expression; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000502:physiology* / Q000528:radiation effects; D063150:Polycomb Repressive Complex 1 / Q000235:genetics; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D014464:Ultrasonic Therapy; D000069453:Ultrasonic Waves; D015854:Up-Regulation
chemical_list: C489420:Bmi1 protein, rat; D063150:Polycomb Repressive Complex 1
keywords: Bone healing; Bone mesenchymal stem cells; C3H10T1/2; Low-intensity pulsed ultrasound