Definition of a simple statistical parameter for the quantification of orientation in two dimensions: Application to cells on grooves of nanometric depths
Definition of a simple statistical parameter for the quantification of orientation in two dimensions: Application to cells on grooves of nanometric depths
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DOI：
10.1016/j.actbio.2010.01.038
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发表时间：
2010-07-01
影响因子：
9.7
通讯作者：
Anselme, K.
中科院分区：
文献类型：
--
作者：
Davidson, P.;Bigerelle, M.;Anselme, K.
接触导向通常通过测量细胞的取向角来评估。然而，很少对这些参数进行统计分析。在此我们提出一种基于一个新参数σ（取向参数）的统计分析，它被定义为取向角分布的离散度。这个参数可用于获得一个截断的高斯分布，该分布对 -90度到 +90度之间的数据分布进行建模。我们确定了取向参数的一个阈值，低于该阈值的数据可被认为在95%置信区间内是对齐的。将我们的取向参数应用于沟槽上的细胞并使用一种建模方法，我们建立了关系σ = α(meas) + (52度 - α(meas))/(1 + CGDER)，其中参数C - GDE代表细胞对沟槽深度的敏感度，R为沟槽深度。所获得的C - GDE值使我们能够在涉及不同沟槽深度、培养时间和接种密度的实验中比较人骨祖细胞（HOP）的接触导向。我们证明HOP细胞能够识别并对30、100、200和500 nm深的沟槽的存在做出反应，并且沟槽越深，细胞取向越高。敏感度（C - GDE）随培养时间的演变大致呈具有渐近线的S形，渐近线是接种密度的函数。这里定义的σ参数是一个通用参数，可应用于所有取向测量，并且不需要数学背景或方向统计学知识。（C）2010 Acta Materialia Inc. 由Elsevier Ltd.出版。保留所有权利。
Contact guidance is generally evaluated by measuring the orientation angle of cells. However, statistical analyses are rarely performed on these parameters. Here we propose a statistical analysis based on a new parameter sigma, the orientation parameter, defined as the dispersion of the distribution of orientation angles. This parameter can be used to obtain a truncated Gaussian distribution that models the distribution of the data between -90 degrees and +90 degrees. We established a threshold value of the orientation parameter below which the data can be considered to be aligned within a 95% confidence interval. Applying our orientation parameter to cells on grooves and using a modelling approach, we established the relationship sigma = alpha(meas) + (52 degrees - alpha(meas))/(1 + CGDER) where the parameter C-GDE represents the sensitivity of cells to groove depth, and R the groove depth. The values of C-GDE obtained allowed us to compare the contact guidance of human osteoprogenitor (HOP) cells across experiments involving different groove depths, times in culture and inoculation densities. We demonstrate that HOP cells are able to identify and respond to the presence of grooves 30, 100, 200 and 500 nm deep and that the deeper the grooves, the higher the cell orientation. The evolution of the sensitivity (C-GDE) with culture time is roughly sigmoidal with an asymptote, which is a function of inoculation density. The sigma parameter defined here is a universal parameter that can be applied to all orientation measurements and does not require a mathematical background or knowledge of directional statistics. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.