Colored polydimethylsiloxane micropillar arrays for high throughput measurements of forces applied by genetic model organisms
Colored polydimethylsiloxane micropillar arrays for high throughput measurements of forces applied by genetic model organisms
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DOI：
10.1063/1.4906905
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发表时间：
2015-01-01
期刊：
影响因子：
3.2
通讯作者：
Koushika, Sandhya P.
中科院分区：
文献类型：
--
作者：
Khare, Siddharth M.;Awasthi, Anjali;Koushika, Sandhya P.
测量多细胞生物所施加的力对于研究其运动的生物力学是有价值的。已经开发了几种技术来测量这种力，例如，应变仪，微加工传感器和校准杠杆。我们引入了一种创新的技术组合作为高通量筛选工具，以评估多种遗传模式生物所施加的力。首先，我们制造了彩色聚二甲基硅氧烷（PDMS）微柱，其中颜色增强了对比度，使其更容易检测和跟踪由生物体驱动的柱位移。其次，我们开发了一个半自动化的图形用户界面来分析柱位移的图像，从而将每只动物的分析时间减少到几分钟。颜色的加入降低了PDMS的杨氏模量。因此，使用Yeoh的超弹性模型表征染料-PDMS复合材料，并使用硅基力传感器校准柱。我们使用我们的设备来测量野生型和突变型秀丽隐杆线虫在琼脂糖表面上移动所施加的力。野生型C。秀丽线虫在单个支柱上施加的平均力近似于1 μ N，总平均力近似于7.68 μ N。我们证明了C.秀丽线虫比它的四肢更有力。我们发现C.与野生型动物相比，具有缺陷体壁肌肉的秀丽线虫突变体在单个支柱上施加显著更低的力，而在感知外部施加的机械力方面有缺陷的突变体仍然在每个支柱上施加相同的平均力。每个支柱施加的平均力与动物的长度、直径或角质层硬度无关。我们还首次使用该设备测量了果蝇幼虫施加的力。蠕动波发生在0.4Hz，施加类似于1.58 μ N的平均力在一个单一的支柱。我们的彩色微流体装置沿着其位移跟踪软件，使我们能够测量多个模型生物体所施加的力，这些生物体在其环境中爬行或滑动。(C)2015年AIP Publishing LLC。
Measuring forces applied by multi-cellular organisms is valuable in investigating biomechanics of their locomotion. Several technologies have been developed to measure such forces, for example, strain gauges, micro-machined sensors, and calibrated cantilevers. We introduce an innovative combination of techniques as a high throughput screening tool to assess forces applied by multiple genetic model organisms. First, we fabricated colored Polydimethylsiloxane (PDMS) micropillars where the color enhances contrast making it easier to detect and track pillar displacement driven by the organism. Second, we developed a semiautomated graphical user interface to analyze the images for pillar displacement, thus reducing the analysis time for each animal to minutes. The addition of color reduced the Young's modulus of PDMS. Therefore, the dye-PDMS composite was characterized using Yeoh's hyperelastic model and the pillars were calibrated using a silicon based force sensor. We used our device to measure forces exerted by wild type and mutant Caenorhabditis elegans moving on an agarose surface. Wild type C. elegans exert an average force of similar to 1 mu N on an individual pillar and a total average force of similar to 7.68 mu N. We show that the middle of C. elegans exerts more force than its extremities. We find that C. elegans mutants with defective body wall muscles apply significantly lower force on individual pillars, while mutants defective in sensing externally applied mechanical forces still apply the same average force per pillar compared to wild type animals. Average forces applied per pillar are independent of the length, diameter, or cuticle stiffness of the animal. We also used the device to measure, for the first time, forces applied by Drosophila melanogaster larvae. Peristaltic waves occurred at 0.4Hz applying an average force of similar to 1.58 mu N on a single pillar. Our colored microfluidic device along with its displacement tracking software allows us to measure forces applied by multiple model organisms that crawl or slither to travel through their environment. (C) 2015 AIP Publishing LLC.