The properties of mucus in a person with asthma can alter with disease process so that it may lead to the airway embolism. Fe 2O 3 nanoparticles can be used for drug delivery. Up till now, however, little is known about how the Fe 2O 3 nanoparticles influence the properties of airway mucus. In this study, Fe 2O 3 nanoparticles were dispersed with ultrasound, and the morphological properties were measured with scanning electron microscope, atomic force microscope and nanometer laser particle size and zeta potential analyzer. Then the dispersed Fe 2O 3 nanoparticles were added to the simulated asthma airway mucus with different final concentration (0.03, 0.3, and 0.4 mg/mL). The measurements of flow curve, yield stress, large amplitude oscillatory shear (LAOS) and shock scanning were carried out with a rotational rheometer. Experimental results showed that the Fe 2O 3 nanoparticles reduced the zero shear viscosity of simulated asthma airway mucus. With increase of shear rate, the wind speed of mucus was reduced. The yield stress of simulated asthma airway mucus was 19.0 Pa, but the yield stresses of experimental group (0.03, 0.3 and 0.4 mg/mL) were 17.0, 0.99, and 0.7 Pa, respectively. The results showed that the viscoelastic modulus of asthma airway mucus treated with Fe 2O 3 nanoparticles were changed obviously as measured with large amplitude scanning and frequency scanning. By adopting the method of optical phase microscopy, we found that different structures of simulated airway mucus were absorbed. The results showed Fe 2O 3 nanoparticles distroyed mucus structure. The experimental results proved that Fe 2O 3 nanoparticles could change the rheological characteristics of simulated asthma airway mucus. This experimental result would lay a foundation for the further development of airway mucus sticky agent based on the function of Fe 2O 3 nanoparticles.
哮喘患者气道黏液流变特性易发生变化引发气道栓塞。Fe 2O 3 纳米颗粒是一种可经气道输送的药物载体，但其对气道黏液流变特性的影响未见报道。本实验用超声波法分散 Fe 2O 3 纳米颗粒，采用扫描电镜、原子力显微镜和纳米激光粒度及 zeta 电位分析仪对其分散结果进行表征；将分散后的 Fe 2O 3 纳米颗粒加入到模拟哮喘气道黏液中（终浓度分别为 0.03、0.3、0.4 mg/mL）。用旋转流变仪进行流动曲线、屈服应力、大幅振荡剪切检测黏液流变学特性的变化。实验结果显示，Fe 2O 3 纳米颗粒处理使模拟哮喘气道黏液的零剪切粘度降低，且随着剪切速率的增加，黏液的结缠速度降低；对照组模拟哮喘气道黏液的屈服应力为 19.0 Pa，而经 Fe 2O 3 纳米颗粒处理（0.03、0.3 和 0.4 mg/mL）的模拟哮喘黏液的屈服应力分别是为 17.0、0.99 和 0.7 Pa；经 Fe 2O 3 纳米颗粒处理的模拟哮喘气道黏液在大振幅扫描和低频到高频剪切震荡扫描下，其粘弹性模量均出现了较明显的变化。采用光学方法观察气道黏液结构的结果显示，Fe 2O 3 纳米颗粒破坏了黏液网状结构。实验结果表明，Fe 2O 3 纳米颗粒会改变模拟哮喘气道黏液的流变学特性，本研究的结果可为进一步开发基于 Fe 2O 3 纳米颗粒的气道黏液解黏剂奠定相应的理论基础。.
Keywords: Fe2O3 nanoparticles; airway mucus; asthma; rheology.