Besseris George J, Yeates Donovan B
Department of Medicine, The University of Illinois at Chicago, Chicago, Illinois 60680, USA.
J Chem Phys. 2007 Sep 14;127(10):105106. doi: 10.1063/1.2766947.
The polymer properties of canine mucus were investigated through the method of rotating magnetic particle microrheometry. Mucus is visualized as a physically entangled biopolymer of low polydispersity in a water-based solution. Mucus was modeled according to the constitutive law of a Doi-Edwards fluid. The magnetic-particle equation of rotational motion is analytically solved in the linear viscoelastic limit rendering theoretical flow profiles which are used to fit the experimental trace signals of the particle remanent-magnetic-field decay. The zero-shear-rate viscosity was found to be 18,000 P and the relaxation time at about 42 s. The molecular weight between entanglements for mucins was estimated at 1.7 MDa rendering an estimation of about seven physical cross-links per molecule. Rheological investigations were extended also to diluted and concentrated rations of the normal mucus simulating the conditions found in more physiological extremes.
通过旋转磁性颗粒微流变学方法研究了犬类黏液的聚合物特性。黏液可视作水基溶液中一种低多分散性的物理缠结生物聚合物。黏液根据Doi-Edwards流体的本构定律进行建模。在线性粘弹性极限下解析求解磁性颗粒的旋转运动方程，得出理论流动曲线，用于拟合颗粒剩余磁场衰减的实验跟踪信号。发现零剪切速率粘度为18000泊，松弛时间约为42秒。黏蛋白的缠结间分子量估计为1.7兆道尔顿，即每个分子约有七个物理交联。流变学研究还扩展到模拟更极端生理条件下发现的正常黏液的稀释和浓缩比例。
