Effects of cyclic fluid stress at different frequencies on behaviors of cells incubated on titanium alloy

• Published in: Biochemical and biophysical research communications Vol. 522; no. 1; pp. 100 - 106
• Main Authors: Lei, Xing, Wu, Hao, Song, Yue, Liu, Bin, Zhang, Shuai-Shuai, Li, Jun-Qin, Bi, Long, Pei, Guo-Xian
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 29.01.2020
• Subjects: Alignment; BMSCs; Cyclic fluid shear stress; Differentiation; Fibroblasts; Vinculin; Fibroblasts; Alignment; Differentiation; Vinculin; BMSCs; Cyclic fluid shear stress
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2019.11.070

The orthopedic external fixation is always in dynamic mechanical environment with the somatic movement. We used a self-designed mini oscillator to simulate this condition by providing the reciprocating cyclic fluid stress, and observed the behavioral responses of fibroblasts implanted on titanium alloy plane to the stress at different frequencies, including 0.2 Hz, 0.6 Hz, and 1.0 Hz. We found that the cell angle, shape index and expression of vinculin were mostly biphasic-dependent with the increase of frequency, with peaks at 0.6 Hz. Whereas the cell area, expression of Col-I and α-SMA were mainly affected by the 1.0 Hz stress. Interestingly, 1.0 Hz stress also promoted Col-I expression of bone marrow mesenchymal stem cells (BMSCs), although it did not increase α-SMA. These results reveal that 0.6 Hz stress improves the alignment, polarity and adherence of fibroblasts on titanium alloy substrates, thus improving the sealing of implants; the 1.0 Hz force activates the differentiation of fibroblasts into myofibroblasts and increases collagen produced by stem cells, which probably cause the formation of fibrous capsules around implants. Schematic diagram of the effect of mechanics on skin-implant sealing. [Display omitted] •The alignment, polarity and vinculin expression of fibroblasts were most sensitive to the 0.6Hz stress.•The fibroblasts differentiation into myofibroblasts was promoted by 1.0Hz fluid stress.•1.0Hz force increased the area and Col-I expression of BMSCs, but not α-SMA.•0.6Hz stress may be helpful to improve the sealing of implants.•1.0Hz force probably causes the pathological fibrous capsules around the implants.