探討低頻電磁場對成骨組織和刺激發炎反應之影響

The Effect of Low-frequency Electromagnetic Fields on Stimulating Inflammatory Reaction and Bone Tissue Engineering

林佑任(Yu-Jen Lin)

指導教授 ： 林忻怡

國立臺北科技大學/工程學院/生物科技研究所/碩士(2009年)

摘要

低頻電磁場(low-frequency electromagnetic field, EMF)常被應用在臨床上治療骨不癒合。超過1公分以上的骨缺損目前尚無法以電磁場做有效治療而傾向以組織工程的方式將具有生物相容性多孔的支架植入缺損處，誘導細胞長入缺陷，加速組織修復。植入手術後引起ㄧ連串發炎反應，導致纖維母細胞引入常使骨組織修復不完整。本研究探討電磁場對發炎反應之刺激作用及其後續對生長在細胞支架上的骨母細胞之生長及分化之影響。
將骨母細胞植入在幾丁聚醣多孔狀細胞支架上與巨噬細胞共同培養，利用脂多醣刺激巨噬細胞引起發炎反應後，照射9小時的電磁場(強度：18-30 Gauss、頻率：75 Hertz、脈衝寬：1.3 milliseconds、振幅：3.5±1 millivolt)。在照射後立即與照射後7天測量支架上骨母細胞之活性、增殖、分化、鹼性磷酸

關鍵字

電磁場 ； 骨母細胞 ； 幾丁聚醣支架 ； 發炎反應

並列摘要

Low-frequency Pulsed Electromagnetic Field (EMF) has been proved by the FDA to be used in clinical applications to treat non-union bone fractures and to release pain. Bone defects over the size of 1cm usually can’t be repaired by EMF alone and requires the used of tissue engineered scaffolds. Implanting osteogenic porous scaffolds can induce bone cell growth and promote tissue repair. However, surgical processes cause inflammatory reactions and macrophages, one of the non-specific inflammatory cells, are known to bring in fibroblast cells to the surgical sites. Fibrous tissue around implants can impede implant/tissue integration and compromise the function of implant later.
We propose to study the effects of EMF on the behaviours of macrophages during inflammation and how the effects influence the subsequent bone repair. Bone cells (7F2 osteoblast) were seeded on chitosan porous scaffolds and co-cultured with macrophage (raw264.7). Lipopolysaccharide was added to the culture medium to induce macrophage to release NO and inflammatory cytokines. The co-culture was exposed to electromagnetic field (18-30 Gauss, 75Hz, impulse width 1.3 ms) for 9 hours. Immediately and seven days after EMF exposure, osteoblast cell viability, proliferation, gene expressions (type I collagen, osteocalcin), ALP activity were measured. NO release from macrophage were measured as well.
Our results showed the concentrations of NO were lower in control than the EMF group at both time points. Osteoblasts in the EMF group had higher proliferation rate and cell viability but lower ALP activity compared to the control group. The results showed that thought EMF did not suppress the inflammatory reactions of macrophages in the co-culture, it did accelerate growth and maturation of osteoblasts with the presence of inflammatory factors. The in vivo effects of EMF suppressing pain and inflammation may not begin with macrophages but other physiological pathways.

並列關鍵字

Low-frequency pulsed electromagnetic field ； osteoblast ； chitosan scaffold ； macrophage inflammatory reaction

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