Zia Uddin Sardar M, Cheng Jiqi, Lin Wei, Qin Yi-Xian
Orthopedic Bioengineering Research Laboratory, Stony Brook University, Stony Brook, NY, USA.
Orthopedic Bioengineering Research Laboratory, Stony Brook University, Stony Brook, NY, USA; Department of Biomedical Engineering, Stony Brook University, Bioengineering Building, Rm 215, Stony Brook, NY 11794, USA.
Cell Mol Bioeng. 2011 Mar;4(1):81-90. doi: 10.1007/s12195-010-0153-8. Epub 2010 Dec 14.
The purpose of this study was to assess the effect of pulsed amplitude modulated ultrasound (pAMUS) on the level of mineralization in osteoblast cell in comparison to cells stimulated with low-intensity pulsed ultrasound (LIPUS). To make the ultrasound effects more enhanced and targeted at region of interest, this study uses a novel approach of applying pulsed amplitude modulated ultrasound to osteoblast cells. The pAMUS signal was generated using two signal generators. Pulsed signal was amplified through a power amplifier and drove two identical focused ultrasound probes, focusing at the same point in the culture dish. The effects of pAMUS were evaluated using a pAMUS signal of 45 kHz and 100 kHz with 20% duty cycle. The hydrophone verified the formation of a focal point at equal distances (16 mm) from the surface of both transducers. Intensity profile using computer controlled 2D scanner showed circular focal point with a diameter of approximately 10 mm. The effect of the signal was studied using MC3T3-E1 cells cultured in osteogenic medium at time points Day 7, 12 and 18. The cells were analyzed for ALP activity and calcium mineralization. The pAMUS significantly increased the ALP activity and matrix calcification in comparison with LIPUS stimulated cultures.
本研究的目的是评估脉冲幅度调制超声（pAMUS）与低强度脉冲超声（LIPUS）刺激的细胞相比，对成骨细胞矿化水平的影响。为了使超声效应更增强且靶向感兴趣区域，本研究采用了一种将脉冲幅度调制超声应用于成骨细胞的新方法。pAMUS信号由两个信号发生器产生。脉冲信号通过功率放大器放大，并驱动两个相同的聚焦超声探头，聚焦于培养皿中的同一点。使用占空比为20%的45kHz和100kHz的pAMUS信号评估pAMUS的效果。水听器验证了在距两个换能器表面等距离（16mm）处形成了一个焦点。使用计算机控制的二维扫描仪进行的强度分布显示出直径约为10mm的圆形焦点。在第7天、12天和18天的时间点，使用在成骨培养基中培养的MC3T3-E1细胞研究信号的效果。分析细胞的碱性磷酸酶（ALP）活性和钙矿化情况。与LIPUS刺激的培养物相比，pAMUS显著提高了ALP活性和基质钙化。
