Biorheology of the vitreous gel

人的眼睛充满了一种玻璃状凝胶，随着年龄的增长，这种凝胶逐渐变得更像液体。凝胶是一种在水溶液中由刚性胶原纤维网络和柔性多糖链组成的复合材料。该项目将探索凝胶结构与其力学和热力学性质之间的关系，以了解这些性质的变化如何与视力障碍相关。该项目将通过研究由玻璃体材料的主要成分制成的重组凝胶来解决这些关系。研究小组将使用各种实验和理论方法来定量了解网络的机械特性和重建凝胶的热力学。该研究结果将为玻璃体相关病理的机械起源提供深入的见解，并可能为治疗视力障碍的有效治疗策略提供指导。该项目的成果将用于生物物理学和相关领域的大学生课程。调查小组将参加几项外联活动，鼓励学生，特别是来自代表性不足群体的学生参与科学和工程学科。此外，该团队将与高中教师一起参加夏季研讨会，以强调高中数学作为大学学习和职业生涯成功基础的重要性。研究人员将通过实验表征玻璃体凝胶主要成分的微流变学，使用透明质酸、II型异型胶原网络的纯化提取物，以及由胶原网络和透明质酸组成的重组复合材料。他们将使用实验和理论相结合的方法来构建重建凝胶的力学相图，该相图可用于将材料特性与结构、微观力学以及透明质酸和胶原蛋白的浓度联系起来。他们将使用实验和分析方法构建重建凝胶的热力学相图，以研究透明质酸和胶原蛋白混合物中的溶胶-凝胶、凝胶崩塌和复杂的凝聚转变。最后，他们将建立重建的玻璃体凝胶的力学和热力学性质的变化与导致视力问题的病理变化之间的联系。该项目将填补我们对玻璃凝胶的材料性质如何与其大分子组织和不同类型的环境线索定量相关的理解空白。它将提供重要的见解在玻璃体凝胶的变化与年龄或眼部病变的发作。该项目的结果可以广泛应用于其他材料，如软生物组织和仿生水凝胶。

CBET - 1604712PI: Das, MoumitaThe human eye is filled with a vitreous gel that becomes progressively more fluid-like with age. The gel is a composite material composed of a network of stiff collagen fibers and flexible polysaccharide chains in an aqueous solution. This project will explore the relationships between the structure of the gel and its mechanical and thermodynamic properties in order to understand how changes in those properties are correlated with vision impairment. The project will address these relationships by studying a reconstituted gel made of the primary components of the vitreous material. The team of investigators will use a variety of experimental and theoretical methods to develop a quantitative understanding of the mechanical properties of the network and the thermodynamics of the reconstituted gel. The results of the study will provide insight into the mechanical origin of vitreous related pathologies and may provide guidance into effective therapeutic strategies to treat vision disorders. Results from the project will be used in courses for university students in biophysics and related fields. The team of investigators will participate in several outreach activities that encourage the participation of students, especially those from underrepresented groups, in science and engineering subjects. In addition, the team will participate with high school teachers in summer workshops to emphasize the importance of high-school mathematics as a foundation for success in college studies and professional careers.The investigators will characterize experimentally the microrheology of the primary components of vitreous gel using purified extracts of hyaluronic acid, type II heterotypic collagen network, and reconstituted composites made of the collagen network and hyaluronic acid. They will use a combination of experimental and theoretical approaches to construct a mechanical phase diagram of reconstituted gel that can be used to relate material properties to structure, micromechanics, and concentrations of hyaluronic acid and collagen. They will construct a thermodynamic phase diagram of the reconstituted gel using experimental and analytical methods to investigate the sol-gel, gel collapse, and complex coacervation transitions in mixtures of hyaluronic acid and collagen. Finally, they will establish connections between changes in mechanical and thermodynamic properties of the reconstituted vitreous gel and pathological changes that lead to vision problems. The project will fill a gap in our understanding of how material properties of vitreous gel are quantitatively related to its macromolecular organization and to different types of environmental cues. It will provide important insights into changes in the vitreous gel with age or with onset of ocular pathologies. Results of the project may apply broadly to other materials such as soft biological tissues and biomimetic hydrogels.