Using magnetic resonance imaging to study enzymatic hydrogelation.
Using magnetic resonance imaging to study enzymatic hydrogelation.
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DOI：
10.1021/ac500967x
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发表时间：
2014-06
影响因子：
7.4
通讯作者：
Weijuan Wang;J. Qian;An-ming Tang;Linna An;K. Zhong;G. Liang
中科院分区：
文献类型：
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作者：
Weijuan Wang;J. Qian;An-ming Tang;Linna An;K. Zhong;G. Liang
在此，我们报告，第一次，使用MRI方法来研究酶的水凝胶化。超分子水凝胶作为生物材料具有广泛的应用前景。然而，水分子在水凝胶中的行为尚未完全了解。在这项工作中，我们设计了一种前体1，它可以自组装成纳米纤维，并在磷酸酶的催化下形成水凝胶I（凝胶I）。系统地研究和分析了含不同浓度1的凝胶I的力学性能、孔径、水扩散速率和磁共振弛豫时间T1和T2的差异。在9.4T下获得I型凝胶体模的T1、T2和扩散加权（1）H MR图像。对MRI数据的分析揭示了这种网络的密度如何影响封装在这种水凝胶中的水质子的弛豫行为。流变学分析和低温透射电镜观察表明，随着浓度的增加，凝胶弹性增加，而凝胶I的孔径减小。这也导致质子弛豫速率的增加（即，缩短的T1、T2和表观扩散系数（ADC））。通过MRI，我们的研究提供了一种新的体外方法来潜在地模拟和研究涉及纤维聚集体的体内疾病。
Herein, we report, for the first time, the use of MRI methods to study enzymatic hydrogelation. Supramolecular hydrogels have been exploited as biomaterials for many applications. However, behaviors of the water molecules encapsulated in hydrogels have not been fully understood. In this work, we designed a precursor 1 which could self-assemble into nanofibers and form hydrogel I (gel I) upon the catalysis of phosphatase. The differences of mechanic property, pore size, water diffusion rate, and magnetic resonance relaxation times T1 and T2 of gel I containing different concentrations of 1 were systematically studied and analyzed. T1, T2, and diffusion-weighted (1)H MR images from gel I phantoms were obtained at 9.4 T. Analyses of the MRI data uncovered how the density of the nanofiber networks affects the relaxation behaviors of the water protons encapsulated in such hydrogels. Rheological analyses and cryo-TEM observations showed increased gel elasticities with increased concentrations of 1 while the pore sizes of gel I decreased. This also resulted in an increase in the proton relaxation rate (i.e., shortened T1, T2, and apparent diffusion coefficient (ADC)) for the water encapsulated in the hydrogel. With MRI, our study provides a new in vitro method to potentially mimic and study in vivo diseases that involve fibrous aggregates.