Domínguez-García Pablo, Dietler Giovanni, Forró László, Jeney Sylvia
Dep. Física Interdisciplinar, Universidad Nacional de Educación a Distancia (UNED), Madrid 28040, Spain.
Soft Matter. 2020 May 7;16(17):4234-4242. doi: 10.1039/c9sm02228g. Epub 2020 Apr 16.
By a micro-experimental methodology, we study the ongoing molecular process inside coarse fibrin networks by means of microrheology. We made these networks gelate around a probe microbead, allowing us to observe a temporal evolution compatible with the well-known molecular formation of fibrin networks in four steps: monomer, protofibril, fiber and network. Thanks to the access that optical-trapping interferometry provides to the short-time scale on the bead's Brownian motion, we observe a Kelvin-Voigt mechanical behavior from low to high frequencies, range not available in conventional rheometry. We exploit that mechanical model for obtaining the characteristic lengths of the filamentous structures composing these fibrin networks, whose obtained values are compatible with a non-affine behavior characterized by bending modes. At very long gelation times, a ω power-law is observed in the loss modulus, theoretically related with the longitudinal response of the molecular structures.
通过一种微观实验方法，我们借助微观流变学研究粗纤维蛋白网络内部正在进行的分子过程。我们使这些网络在探针微珠周围凝胶化，从而能够观察到与纤维蛋白网络众所周知的分子形成过程在四个步骤中相兼容的时间演变：单体、原纤维、纤维和网络。由于光镊干涉测量法能够在短时间尺度上获取微珠布朗运动的信息，我们观察到从低频到高频的开尔文 - 维格纳力学行为，这是传统流变学无法实现的频率范围。我们利用该力学模型来获取构成这些纤维蛋白网络的丝状结构的特征长度，其得到的值与以弯曲模式为特征的非仿射行为相兼容。在非常长的凝胶化时间下，在损耗模量中观察到ω幂律，理论上这与分子结构的纵向响应有关。
