高分辨率细胞牵引力频域反演技术

High-resolution cellular traction force recovery in two-dimensional Fourier domain

目的针对经典细胞牵引力反演算法的病态特征,发展基于二维傅立叶空间的高分辨率细胞牵引力反演新技术。方法根据基底表面位移测量数据和积分核函数在二维傅立叶空间各自的分布特点和规律,探讨牵引力反演过程中出现的反卷积病态现象,构建一套自适应加窗滤波算法来约束反演计算过程中出现的高频噪声放大效应。结果经典细胞牵引力频域反演算法(Fourier transform traction cytometry,FTTC)具有明显的反卷积病态特征,特别是在位移采样网格较密情况下,牵引力反演结果极不可靠。利用本文提出的频域滤波方法则能显著削弱位移场高频噪声对于力反演结果的影响。结论这种细胞牵引力频域反演新方法可有效抑制反问题病态现象的发生,显著提高力场测量的稳定性和空间分辨率。该方法有望在细胞与胞外基质相互作用研究中得到广泛应用。

Objective To develop a new set of algorithms for high-resolution cellular traction force recovery based on two-dimensional Fourier domain by addressing the ill-posed nature of classic cellular force traction recovery.Methods By exploring the inherent characteristics and rules of displacement data on the substrates and Green＇s function in the Fourier domain,the phenomenon of ill-posed deconvolution arising in cellular force traction recovery was investigated and a set of self-adaptive filtering algorithms was consequently developed to remarkably restrain the high frequency noise amplification.Results The ill-posed nature of classical Fourier transform traction cytometry（FTTC） made cellular traction force recovery extremely unstable,especially for relatively dense displacement data sampling.In contrast,the proposed self-adaptive filtering algorithms based on FTTC could make cellular traction force distribution more stable and reliable,as the effect of high frequency noise in displacement field on recovery results was weakened significantly.Conclusions This new technique for cellular traction force recovery can effectively suppress the noise and therefore improve the stability of force recovery procedure and spatial resolution,which is expected to find wider application in the study of cell-substrate interactions.