Wang Jue, Tang Na, Xiao Qiang, Zhang Li, Li Yu, Li Juan, Wang Jun, Zhao Zhihe, Tan Lijun
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Bioelectromagnetics. 2015 Jan;36(1):35-44. doi: 10.1002/bem.21882. Epub 2014 Oct 30.
Recapitulation of embryonic endochondral bone formation is a promising alternative approach to bone tissue engineering. However, the time-consuming process is one of the reasons the approach is unpractical. Here, we aimed at accelerating the in vitro endochondral ossification process of tissue engineering by using a pulsed electromagnetic field (PEMF). The rat bone marrow-derived stem cells were chondrogenic or hypertrophic differentiated in a three-dimensional pellet culture system, and treated with different intensities of PEMF (1, 2, and 5 mT with modulation frequency 750 Hz, carrier frequency 75 Hz and a duty ratio of 0.8, 3 h/day for 4 weeks). The effects of PEMF on hypertrophy and endochondral ossification were assessed by safranin O staining, immunohistochemistry, and quantitative real-time polymerase chain reaction. The results suggest that PEMF at 1, 2, and 5 mT may inhibit the maintenance of the cartilaginous phenotype and increase cartilage-specific extracellular matrix degradation in the late stage of chondrogenic differentiation. In addition, among the three different intensities, only PEMF at 1 mT directed the differentiation of chondrogenic-induced stem cell pellets to the hypertrophic stage and promoted osteogenic differentiation. Our findings provide the feasibility to optimize the process of in vitro endochondral ossification with PEMF stimulation.
胚胎软骨内骨形成的重现是骨组织工程一种有前景的替代方法。然而，这个耗时的过程是该方法不实用的原因之一。在此，我们旨在通过使用脉冲电磁场（PEMF）来加速组织工程的体外软骨内骨化过程。大鼠骨髓来源的干细胞在三维微球培养系统中进行软骨形成或肥大分化，并接受不同强度的PEMF处理（1、2和5 mT，调制频率750 Hz，载波频率75 Hz，占空比0.8，每天3小时，共4周）。通过番红O染色、免疫组织化学和定量实时聚合酶链反应评估PEMF对肥大和软骨内骨化的影响。结果表明，1、2和5 mT的PEMF可能在软骨形成分化后期抑制软骨表型的维持并增加软骨特异性细胞外基质降解。此外，在三种不同强度中，只有1 mT的PEMF引导软骨形成诱导的干细胞微球分化至肥大阶段并促进成骨分化。我们的研究结果为通过PEMF刺激优化体外软骨内骨化过程提供了可行性。
