Antonio Palma D, Lasalvia Maria, Perna Giuseppe, Capozzi Vito
Dipartimento di Medicina Clinica e Sperimentale, Università di Foggia, Viale Pinto, Italy.
Biochim Biophys Acta. 2012 Dec;1818(12):3141-8. doi: 10.1016/j.bbamem.2012.08.001. Epub 2012 Aug 9.
The roughness of cell membrane is a very interesting indicator of cell's health state. Atomic Force Microscopy allows us to investigate the roughness of cell membrane in great detail, but the obtained roughness value is scale-dependent, i.e. it strongly depends on measurement parameters, as scanning area and step size. The scale-dependence of the roughness value can be reduced by means of data filtration techniques, that are not standardized at nanometric scale, especially as far as biological data are concerned. In this work, a new method, based on the changes of values of some roughness parameter (root mean square roughness and skewness) as a function of filtration frequencies, has been implemented to optimize data filtering procedure in the calculation of cell membrane roughness. In this way, a root mean square roughness value independent of cell shape, membrane micro-irregularities and measurement parameters can be obtained. Moreover, different filtration frequencies selected with this method allow us to discriminate different surface regimes (nominal form, waviness and roughness) belonging to the raw cell profile, each one related to different features of the cell surface.
细胞膜的粗糙度是细胞健康状态的一个非常有趣的指标。原子力显微镜使我们能够非常详细地研究细胞膜的粗糙度，但所获得的粗糙度值与尺度有关，即它强烈依赖于测量参数，如扫描面积和步长。粗糙度值的尺度依赖性可以通过数据过滤技术来降低，而这些技术在纳米尺度上并未标准化，尤其是就生物数据而言。在这项工作中，一种基于某些粗糙度参数（均方根粗糙度和偏度）值随过滤频率变化的新方法已被实施，以优化细胞膜粗糙度计算中的数据过滤程序。通过这种方式，可以获得一个与细胞形状、膜微观不规则性和测量参数无关的均方根粗糙度值。此外，用这种方法选择的不同过滤频率使我们能够区分属于原始细胞轮廓的不同表面状态（名义形状、波纹度和粗糙度），每一种状态都与细胞表面的不同特征相关。
