Advanced Soft Matter, Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands.
1] Advanced Soft Matter, Department of Chemical Engineering, Delft University of Technology, Delft, The Netherlands. [2] Institute for BioNanotechnology in Medicine, Northwestern University, Chicago, Illinois, USA.
Nat Protoc. 2014 Apr;9(4):977-88. doi: 10.1038/nprot.2014.055. Epub 2014 Mar 27.
This protocol details the preparation of low-molecular-weight hydrogels (LMWGs) in which the gelation time and mechanical stiffness of the final gel can be tuned with the concentration of the catalyst used in the in situ formation of the hydrogelator. By altering the rate of formation of the hydrazone-based gelator from two water-soluble compounds--an oligoethylene functionalized benzaldehyde and a cyclohexane-derived trishydrazide--in the presence of acid or aniline as catalyst, the kinetics of gelation can be tuned from hours to minutes. The resulting materials display controllable stiffness in the 5-50 kPa range. This protocol works at ambient temperatures in water, at either neutral or moderately acidic pH (phosphate buffer, pH 5) depending on the catalyst used. The hydrazide and aldehyde precursors take a total of 5 d to prepare. The final gel is prepared by mixing aqueous solutions of the two precursors and can take between minutes and hours to set, depending on the catalytic conditions. We also describe analysis of the hydrogels by critical gel concentration (CGC) tests, rheology and confocal laser-scanning microscopy (CLSM).
本方案详细介绍了低分子量水凝胶（LMWG）的制备方法，通过改变用于水凝胶形成的原位催化剂的浓度，可以调节最终凝胶的凝胶时间和机械硬度。通过改变在酸或苯胺作为催化剂存在下两种水溶性化合物——具有聚乙二醇官能化的苯甲醛和环己烷衍生的三酰肼——形成腙基凝胶剂的速率，可以将凝胶化动力学从数小时调节到数分钟。所得材料在 5-50 kPa 的范围内具有可控的硬度。该方案在环境温度下、中性或中等酸性 pH（磷酸缓冲液，pH 5）下的水中进行，具体取决于所用的催化剂。酰肼和醛前体总共需要 5 天时间来制备。最终凝胶是通过混合两种前体的水溶液制备的，根据催化条件的不同，凝胶的形成时间可在几分钟到几小时之间。我们还描述了通过临界凝胶浓度（CGC）测试、流变学和共聚焦激光扫描显微镜（CLSM）对水凝胶进行的分析。
