Silk Hydrogels of Tunable Structure and Viscoelastic Properties Using Different Chronological Orders of Genipin and Physical Cross-Linking.
Silk Hydrogels of Tunable Structure and Viscoelastic Properties Using Different Chronological Orders of Genipin and Physical Cross-Linking.
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DOI：
10.1021/acsami.5b02308
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发表时间：
2015-06-10
影响因子：
9.5
通讯作者：
Migliaresi C
中科院分区：
文献类型：
--
作者：
Elliott WH;Bonani W;Maniglio D;Motta A;Tan W;Migliaresi C
使水凝胶制造过程朝向用于预期生物医学用途的定义的粘弹性对水凝胶支架功能和细胞分化是重要的。丝素蛋白水凝胶可以在高压二氧化碳处理期间通过β-折叠结晶进行“物理”交联，或通过京尼平进行共价“化学”交联。我们在这里证明，通过改变京尼平交联与β-折叠形成的时间顺序，在丝素蛋白水凝胶中可调节时间依赖性机械性能。京尼平在β-折叠形成之前交联通过增加分子量、影响凝胶形态和降低刚度响应来影响凝胶化机制。或者，京尼平交联后凝胶锚定的蛋白质链的无定形区域，并增加刚度。在分子和微米长度尺度下结合材料表征后，通过接近生理水平的大幅振荡应变突出显示并验证了这些差异。
Catering the hydrogel manufacturing process toward defined viscoelastic properties for intended biomedical use is important to hydrogel scaffolding function and cell differentiation. Silk fibroin hydrogels may undergo “physical” cross-linking through β-sheet crystallization during high pressure carbon dioxide treatment, or covalent “chemical” cross-linking by genipin. We demonstrate here that time-dependent mechanical properties are tunable in silk fibroin hydrogels by altering the chronological order of genipin cross-linking with β-sheet formation. Genipin cross-linking before β-sheet formation affects gelation mechanics through increased molecular weight, affecting gel morphology, and decreasing stiffness response. Alternately, genipin cross-linking after gelation anchored amorphous regions of the protein chain, and increasing stiffness. These differences are highlighted and validated through large amplitude oscillatory strain near physiologic levels, after incorporation of material characterization at molecular and micron length scales.