Okeyoshi Kosuke, Osada Kensuke, Okajima Maiko K, Kaneko Tatsuo
Japan Advanced Institute of Science and Technology;
Department of Bioengineering, School of Engineering, The University of Tokyo.
J Vis Exp. 2017 Apr 7(122):55274. doi: 10.3791/55274.
Living organisms that use water are always prone to drying in the environment. Their activities are driven by biopolymer-based micro- and macro-structures, as seen in the cases of moving water in vascular bundles and moisturizing water in skin layers. In this study, we developed a method for assessing the effect of aqueous liquid crystalline (LC) solutions composed of biopolymers on drying. As LC biopolymers have megamolecular weight, we chose to study polysaccharides, cytoskeletal proteins, and DNA. The observation of biopolymer solutions during drying under polarized light reveals milliscale self-integration starting from the unstable air-LC interface. The dynamics of the aqueous LC biopolymer solutions can be monitored by evaporating water from a one-side-open cell. By analyzing the images taken using cross-polarized light, it is possible to recognize the spatio-temporal changes in the orientational order parameter. This method can be useful for the characterization of not only artificial materials in various fields, but also natural living tissues. We believe that it will provide an evaluation method for soft materials in the biomedical and environmental fields.
依赖水生存的生物体在环境中总是容易干燥。它们的活动由基于生物聚合物的微观和宏观结构驱动，如维管束中输送水分以及皮肤层中保持水分的情况。在本研究中，我们开发了一种评估由生物聚合物组成的水性液晶（LC）溶液对干燥影响的方法。由于LC生物聚合物具有超大分子量，我们选择研究多糖、细胞骨架蛋白和DNA。在偏振光下观察干燥过程中的生物聚合物溶液，可发现从不稳定的空气-LC界面开始的毫米级自组装。通过从单侧开口的小室中蒸发水分，可以监测水性LC生物聚合物溶液的动力学。通过分析使用交叉偏振光拍摄的图像，能够识别取向序参数的时空变化。该方法不仅可用于表征各个领域的人工材料，还可用于天然生物组织。我们相信它将为生物医学和环境领域的软材料提供一种评估方法。
