牙科矯正用靜磁鐵磁場對細胞生長影響機制之探討

牙科靜磁鐵在臨床應用上是近二十年的事。但由於矯正所使用的靜磁鐵是屬於開放性的靜磁場，其對於生物體的細胞生長影響機制為何，目前仍不明且缺乏深入的研究。此外，過去的研究及文獻也顯示，靜磁場對於細胞的影響，會因細胞種類或環境的不同而有不同的結果。且靜磁場的刺激環境磁力大小導致其細胞生長速率的增加或減緩之作用機制尚未明確且模糊不清。因此，找出靜磁場刺激細胞後，其導致細胞生長速率的增加或減緩之作用機制實為必需。雖然Labes(1966)曾提出靜磁場可能會影響細胞膜的脂質分子，但卻從來沒有實驗去驗證過這個假說，因此靜磁場作用於細胞的哪個部分，目前並不清楚。本研究選取纖維母細胞為研究對象，對前述之問題，在其暴露於0到4000高斯的靜磁場0到48小時計算細胞數目增長情形，並以電子顯微鏡觀察其超微結構，接者以免疫螢光酵素分析法進行PGE2的量測。此外，細胞暴露於上述靜磁場時，細胞週期之變化亦利用流氏細胞儀來測定。結果發現，暴露於靜磁場下的細胞數目在第12小時有最大的變化，在1000到4000高斯時分別減少了5.8%, 11.6%和20.9%。而細胞週期並未有明顯的改變，且PGE2釋放亦無變化，但在4000高斯之靜磁場作用下加入IGF-I, PDGF-bb, TGF-β之細胞數目分別較控制組少了14.0%, 12.4% 和15.4%。而處理以TNF-α之細胞數目則多了18.0%。從此結果推論，靜磁場可能會影響細胞膜，減緩生長因子作用但不影響到DNA層次，亦無PGE2增加之發炎反應副作用產生。

關鍵字

靜磁場；纖維母細胞；細胞生長

並列摘要

Static magnet has been used in the dental field for about 20 years. Clinical studies showed that magnets could not only offer force control and treatment convenience, it could also increase the rate of tooth movement in orthodontic treatment. However, the effect of orthodontic static magnetic field on growth stimulation of cell remains unclear and still need further study. In this study, our objective is to determine how the static magnet affects cell cycle and its mechanism. Cell number and viability of fibroblast (NIH-3T3) were tested under static magnetic field (SMF) exposure. Results showed that both cell number and viability of cells decreased when exposed to SMF. However, no statistically significant difference was found between each cell cycle phase when the cells were exposed to various strengths of SMF. In the growth factor experiments, all growth factors IGF-I、TGF-βand PDGF were found to increase the cell number of the cells. However, when the cells were exposed to SMF, the effects of the IGF-I、TGF-βand PDGF on cell number significantly decreased by 14.0%、15.4% and 12.4% (p<0.01) respectively. In contract, TNF-α did significantly increase the cell number of the cells with a percentage of 18.0% (p<0.01) when exposed to SMF. The SEM images showed that no significantly changed when compared to control group after they were exposed to 4000 Gauss SMF within a period of 48 hours. According to these findings, we arrived at a hypothesis that SMF were effected of cell membrane. This interaction may affect the status of various transmembrane growth factor receptors. When the growth factors cannot bind to its receptor, the proliferation rates of the cell decrease.

並列關鍵字

static magnetic field ； fibroblast ； cell growth

參考文獻

Atef MM, Elhaset MSA, Elkareem A, Aida S, Fadel MS. Effects of a static magnetic field on haemoglobin structure and function. Int J Biol Macromol, 17:105-111, 1995.

Balysankiova IV, Krotov KA, Danilov SM. Effect of a static magnetic field on the growth rate and in vitro angiogenesis of endothelial cells. Bullet Exp Biol Med 117: 106-108, 1994.

Berk SG, Srikanth S, Mahajan SM, Ventrice CA. Static uniform magnetic fields and amoebae. Bioelectromagnetics 18: 81-84, 1997.

Birkedal-Hansen H. Role of cytokines and inflammatory mediators in tissue destruction. J periodont Res, 28:500-510, 1993 Blechman AM.

Magnetic force system in orthodontics, clinical results of a pilot study. Am J Orthod, 87: 201-210, 1985.

國際替代計量

牙科矯正用靜磁鐵磁場對細胞生長影響機制之探討

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