Different magnitudes of tensile strain induce human osteoblasts differentiation associated with the activation of ERK1/2 phosphorylation.
Mechanical factors are related to periprosthetic osseointegration following total hip arthroplasty. However, osteoblast response to strain in implanted femurs is unclear because of the absence of accurate stress-measuring methods. In our study, finite element analysis was performed to calculate strain distribution in implanted femurs. 0.8-3.2% tensile strain was then applied to human osteoblasts. Higher magnitudes of strain enhanced the expression of osteocalcin, type I collagen, and Cbfa1/Runx2. Lower magnitudes significantly increased ALP activity. Among these, type I collagen expression increased with the activation of ERK1/2 phosphorylation in a strain-magnitude-dependent manner. Our study marks the first investigation of osteoblast response at different magnitudes of periprosthetic strain. The results indicate that the functional status of human osteoblasts is determined by strain magnitude. The strain distribution in the proximal region of implanted femur should be improved for osseointegration.
Zhu
Junfeng
J
Department of Orthopaedics, Shanghai the 6th People's Hospital, Jiaotong University, Shanghai, 200233, China.
Zhang
Xiaoling
X
Institute of Health Science, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200025, China.
Wang
Chengtao
C
School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, 200030, China.
Peng
Xiaochun
X
Department of Orthopaedics, Shanghai the 6th People's Hospital, Jiaotong University, Shanghai, 200233, China.
Zhang
Xianlong
X
Department of Orthopaedics, Shanghai the 6th People's Hospital, Jiaotong University, Shanghai, 200233, China.