School of Dentistry, College of Medical and Dental Sciences, St Chad's Queensway, University of Birmingham, Birmingham, B4 6NN, UK.
J Bone Miner Metab. 2012 Sep;30(5):602-7. doi: 10.1007/s00774-012-0368-y. Epub 2012 Jul 3.
This study investigated the effects of different frequencies of low intensity ultrasound on osteoblast migration using an in vitro scratch-wound healing assay. Mouse calvarial-derived MC3T3-E1 osteoblasts in culture were exposed to continuous 45 kHz ultrasound (25 mW/cm(2)) or pulsed 1 MHz ultrasound (250 mW/cm(2)) for 30 min followed by 2 days' culture. Ultrasound treatment with either kHz or MHz output similarly and significantly increased cell numbers after 2 days in culture compared with untreated control cultures. In the scratch-wound healing assay the presence of the cell proliferation inhibitor mitomycin C (MMC) did not influence scratch-wound closure in control cultures indicating that cell migration was responsible for the in vitro wound healing. Application of ultrasound significantly stimulated wound closure. MMC did not affect kHz-stimulated in vitro wound healing; however, MMC reduced in part the scratch-wound closure rate in MHz-treated cultures suggesting that enhanced cell proliferation as well as migration was involved in the healing promoted by MHz ultrasound. In conclusion, both continuous kHz and pulsed MHz ultrasound promoted osteoblastic migration; however, subtle differences were apparent in the manner the different ultrasound regimens enhanced in vitro scratch-wound healing.
本研究采用体外划痕愈合试验，探讨了不同频率低强度超声对成骨细胞迁移的影响。在培养过程中，将体外培养的鼠颅骨来源的 MC3T3-E1 成骨细胞暴露于连续 45 kHz 超声（25 mW/cm²）或脉冲 1 MHz 超声（250 mW/cm²）中 30 分钟，然后培养 2 天。与未经处理的对照组相比，kHz 或 MHz 输出的超声处理在培养 2 天后同样显著增加了细胞数量。在划痕愈合试验中，细胞增殖抑制剂丝裂霉素 C（MMC）的存在并不影响对照组的划痕愈合，表明细胞迁移是体外伤口愈合的原因。超声的应用显著刺激了伤口闭合。MMC 不影响 kHz 刺激的体外伤口愈合；然而，MMC 部分降低了 MHz 处理培养物中的划痕愈合率，表明增强的细胞增殖和迁移参与了 MHz 超声促进的愈合。总之，连续的 kHz 和脉冲的 MHz 超声均促进成骨细胞迁移；然而，不同超声方案在增强体外划痕愈合方面的细微差异是明显的。
