Abstract
Background/purpose: Wharton’s jelly mesenchymal stem cells (WJMSCs) are well-known for use in nontissue-specific stem cell therapy. However, they can be a challenge for orthopedic used because they have low osteogenic differentiation ability. Several studies have found that static magnetic fields (SMFs) have positive effects on the osteogenesis of different stem cells. Nevertheless, whether SMFs have similar effects on WJMSC differentiation is unknown. Matrix vesicles are the critical characteristic of osteogenesis. Matrix vesicles serve as the initial site for physiological mineralization. Thus, the purpose of this study was to evaluate the effectiveness of a 0.4-T SMF on osteogenic differentiation and matrix vesicle secretion of WJMSCs.
Methods
In methodology, WJMSCs were treated with a 0.4-T SMF. The cell viability was tested using the MTT assay. For the osteogenic analysis, the alkaline phosphatase activity assay and alizarin red S staining were performed. The osteogenic-related gene expression of ALP, BMP-2, and Runx2 was examined using real-time polymerase chain reaction. Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy was used to analyze matrix vesicle secretion.
Results
The cell viability showed no significant difference between the SMF-treated group and the sham-exposed cells. However, the SMF-treated group exhibited significantly more mineralized nodule formation and higher ALP activity than their control counterparts (p < .05). The expressions of osteogenic-related markers, ALP, BMP-2, and Runx2, were also significantly higher in the SMF-treated WJMSCs. The scanning electron microscopy results showed much more matrix vesicle secretion in the SMF-treated cells than in the sham-treated cells. A mineralized sheath was noted in the SMF-treated cells, along with a sporadic accumulation of spherical mineralized deposits on the cell surface.
Conclusions
The results suggest that 0.4-T SMF treatment enhances the osteogenesis of WJMSCs at the early-to-middle stage of osteogenic differentiation by increasing the matrix vesicle secretion and mineralization.
Acknowledgements
We would like to thank Yu-Xuan Huang and Ya-Hui Chan for their helpful suggestions in the design of our study.
Disclosure statement
The authors report no conflict of interest.
Additional information
Notes on contributors
Ching-Yi Chang
Ching-Yi Chang, DDS, MS, is a Research fellow at Taipei Municipal Wanfang Hospital and Master Student at Taipei Medical University.
Wei-Zhen Lew
Wei-Zhen Lew, DDS, PhD, is a Postdoctoral Researcher at School of Dentistry, Taipei Medical University.
Sheng-Wei Feng
Sheng-Wei Feng, DDS, PhD, is an Associate Professor at School of Dentistry, Taipei Medical University.
Chung-Lung Wu
Chung-Lung Wu is a Visiting Staff at Cathay General Hospital.
Hsin-Hui Wang
Hsin-Hui Wang is a Visiting Staff at Cathay General Hospital.
Sung-Chih Hsieh
Sung-Chih Hsieh, DDS, PhD, is an Associate Professor at School of Dentistry, Taipei Medical University.
Haw-Ming Huang
Haw-Ming Huang, PhD, is a Professor at School of Dentistry, Taipei Medical University.