Viscoelasticity is a crucial property of cells, which plays an important role in label-free cell characterization. This paper reports a model-fitting-free viscoelasticity calculation method, correcting the effects of frequency, surface adhesion and liquid resistance on AFM force-distance (FD) curves. As demonstrated by quantifying the viscosity and elastic modulus of PC-3 cells, this method shows high self-consistency and little dependence on experimental parameters such as loading frequency, and loading mode (Force-volume vs. PeakForce Tapping). The rapid calculating speed of less than 1ms per curve without the need for a model fitting process is another advantage. Furthermore, this method was utilized to characterize the viscoelastic properties of primary clinical prostate cells from 38 patients. The results demonstrate that the reported characterization method a comparable performance with the Gleason Score system in grading prostate cancer cells, This method achieves a high average accuracy of 97.6% in distinguishing low-risk prostate tumors (BPH and GS6) from higher-risk (GS7-GS10) prostate tumors and a high average accuracy of 93.3% in distinguishing BPH from prostate cancer.

中文翻译：

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基于 AFM 的无模型拟合粘弹性表征方法，用于原发性前列腺肿瘤的准确分级

粘弹性是细胞的一个重要特性，在无标记细胞表征中发挥着重要作用。本文提出了一种免模型拟合的粘弹性计算方法，修正了频率、表面粘附力和液体阻力对 AFM 力-距离（FD）曲线的影响。通过量化 PC-3 细胞的粘度和弹性模量证明，该方法具有较高的自一致性，并且对加载频率和加载模式（力-体积与峰值力轻敲）等实验参数的依赖性很小。另一个优点是每条曲线的计算速度小于 1 毫秒，无需模型拟合过程。此外，该方法还用于表征 38 名患者的原代临床前列腺细胞的粘弹性特性。结果表明，所报告的表征方法在前列腺癌细胞分级方面与格里森评分系统具有相当的性能，该方法在区分低风险前列腺肿瘤（BPH 和 GS6）与高风险前列腺肿瘤（GS7）方面达到了 97.6% 的高平均准确度。 -GS10) 前列腺肿瘤，区分 BPH 和前列腺癌的平均准确度高达 93.3%。