特定脈衝式電磁場刺激不論在動物實驗或臨床應用上,對骨折癒合都有良好的治療效果。本實驗主要目的是要找出電磁場刺激對骨母細胞生長較佳的刺激參數。 本研究以新生Wistar 鼠的頭蓋骨來培養骨母細胞。實驗分為兩階段進行。第一階段目的在挑選較佳的刺激時間及天數。此時以本實驗室在體外模式培養下,證明能抑制蝕骨細胞形成的單脈衝波形、頻率(7.5 Hz)及感應電場強度(2 mv/cm)來刺激。欲找出不同刺激時間(1, 2, 4 hrs/day)及持續刺激天數(1, 2, 5 days)中,促進骨母細胞增生較佳的模式。 第二階段實驗中,採用第一階段較佳之刺激參數(4 hrs/day,連續刺激 5天),變因改為刺激頻率。此階段電磁場的刺激參數除頻率(1.5 Hz,7.5 Hz,10 Hz或75 Hz)外,皆與第一階段相同。 評估的項目有:1. 鹼性磷酸脢染色法(ALP Stain),以定性骨母細胞。2. MTT偵測技術,以分析細胞存活率。 研究結果顯示:第一階段實驗中,僅有 4 hrs/day,連續刺激 5天,骨母細胞有增生的現象;第二階段實驗中, 1.5 Hz,7.5 Hz及10 Hz 皆能使骨母細胞有增生的現象,但從生長百分比來看, 1.5 Hz為最佳的頻率。
Pulsed Electromagnetic Fields(PEMF) has many medical applications. Previous animal and clinical studies have clearly showed a positive effect of PEMF on the rate of osseous repair. The purpose of this study is to find the optimal parameters of PEMF stimulation on the growth of osteoblasts. The cranium off new born Wistar rats were harvested and cultured. The experiment were divided into two parts : The first part was to find the better exposure time of the single pulse ( 7.5 Hz ) electromagnetic field with induced electric field intensities of 2 mV/cm, which investigated in our previous studies. A PEMF stimulation was applied to osteoblasts for three different stimulation periods of 1 hour , 2 hours, and 4 hours per day, and 3 stimulation day : 1 day, 2 days, and 5 days. In the second part, we used the better stimulation time in part one of 1.5, 7.5, 10 or 75 Hz on osteoblasts proliferation promotion to find the optimal frequencies. After the stimulation, the alkaline phosphatase ( ALP ) stain would be used for osteoblast cell activity, and the osteoblast cells proliferation were analyzed by the 3-〔4, 5-dimethylthiazol-2-yl〕-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the PEMF could enhance the osteoblast cells proliferation when the stimulation time was 4 hrs/day, and 5 days exposure. The frequency of 1.5Hz, 7.5Hz, or 10Hz could stimulate the osteoblasts proliferation, but 1.5 Hz was more significantly than others.