The structural response of the cornea to changes in stromal hydration
The structural response of the cornea to changes in stromal hydration
复制标题
DOI：
10.1098/rsif.2017.0062
复制
发表时间：
2017-06-01
影响因子：
3.9
通讯作者：
Meek, Keith M.
中科院分区：
文献类型：
--
作者：
Hayes, Sally;White, Tomas;Meek, Keith M.
本研究的主要目的是量化人类和猪的角膜结构和水合作用之间的关系。从用聚乙二醇（PEG）平衡至不同水合水平的人和猪角膜收集X射线散射数据，以获得胶原纤维直径、纤维间距（IFS）和分子间间距的测量值。这两个物种表现出很强的正线性相关性之间的水化和IFS 2和非线性，双相之间的关系，水化和原纤维直径，从而原纤维直径增加到约生理水化，H = 3.0，此后几乎没有变化。高于H = 3.0时，猪角膜显示出比人角膜更大的原纤维直径（p < 0.001）。分子间的间距也随着水化在一个双相的方式，但达到最大值在较低的水化（H = 1.5）比原纤维直径。在所有水合作用下，人角膜显示出比猪角膜更高的分子间间距（p < 0.0001）。人和猪角膜需要相似的PEG浓度以达到生理水合，这表明引起溶胀压力的总固定电荷是相同的。它们对水化的结构反应的差异可以通过分子交联和纤维内/纤维间水分配的变化来解释。
The primary aim of this study was to quantify the relationship between corneal structure and hydration in humans and pigs. X-ray scattering data were collected from human and porcine corneas equilibrated with polyethylene glycol (PEG) to varying levels of hydration, to obtain measurements of collagen fibril diameter, interfibrillar spacing (IFS) and intermolecular spacing. Both species showed a strong positive linear correlation between hydration and IFS2 and a nonlinear, bi-phasic relationship between hydration and fibril diameter, whereby fibril diameter increased up to approximately physiological hydration, H = 3.0, with little change thereafter. Above H = 3.0, porcine corneas exhibited a larger fibril diameter than human corneas (p < 0.001). Intermolecular spacing also varied with hydration in a bi-phasic manner but reached a maximum value at a lower hydration (H = 1.5) than fibril diameter. Human corneas displayed a higher intermolecular spacing than porcine corneas at all hydrations (p < 0.0001). Human and porcine corneas required a similar PEG concentration to reach physiological hydration, suggesting that the total fixed charge that gives rise to the swelling pressure is the same. The difference in their structural responses to hydration can be explained by variations in molecular cross-linking and intra/interfibrillar water partitioning.