Abstract This investigation proposes a synthetic biofluid, artificial sputum medium (ASM) and xanthan gum (XG), that mimics the mucus from a patient with cystic fibrosis, and investigates the rheological properties both macroscopically and microscopically. Macroscopic rheological characterization cannot address the heterogeneity or the behavior of particle transport inside the mucus. Microscopic rheology enables the characterization of the microenvironment by using microparticles as probes. The addition of XG to ASM provides a tunable parameter that enables the mechanical properties to be consistent with real mucus. Particles that were suspended in a media of ASM with XG displayed a subdiffusive behavior at short timescales with a diffusive exponent that decreases with an increase in concentration of XG. At long timescales, particles that were suspended in ASM+XG with a concentration of XG of 0.1% to 0.4% displayed diffusive behavior. While in more concentrated samples (0.5% and 1.0%), the particles were constrained inside local elastic “cages”. The microscopic moduli that were calculated showed consistently lower moduli than rotational rheometry. This discrepancy suggests that the solutions of XG have a hierarchical structure that better represents the weakly associated microstructure of mucus that is found in real sputum.

中文翻译：

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人工痰液流变学增强

摘要 本研究提出了一种合成生物流体、人工痰液培养基 (ASM) 和黄原胶 (XG)，它模拟了囊性纤维化患者的粘液，并从宏观和微观两方面研究了流变学特性。宏观流变学表征无法解决粘液内颗粒传输的异质性或行为。微观流变学通过使用微粒作为探针来表征微环境。将 XG 添加到 ASM 提供了一个可调参数，使机械性能与真实粘液一致。悬浮在具有 XG 的 ASM 介质中的粒子在短时间内显示出亚扩散行为，其扩散指数随着 XG 浓度的增加而降低。在很长一段时间内，悬浮在 ASM+XG 中且 XG 浓度为 0.1% 至 0.4% 的颗粒显示出扩散行为。而在更浓缩的样品（0.5% 和 1.0%）中，颗粒被限制在局部弹性“笼子”内。计算出的微观模量始终显示出低于旋转流变仪的模量。这种差异表明 XG 的溶液具有层次结构，可以更好地代表真实痰液中发现的粘液的弱相关微结构。