Peptide-amphiphile (PA)-based supramolecular thixotropic hydrogels are useful in medical sciences due to multiple advantageous features along with its biocompatibility and biodegradability. In this work, we have developed a self-assembled peptide-based hydrogel from a $$\upbeta $$ β -sheet forming short PA. Hydrogelation of the PA is controlled by pH and consequent changes in secondary structures attained by the PA. Under acidic conditions, the PA remains in random coil conformation. While increasing the pH to 9, a rapid transformation to anti-parallel $$\upbeta $$ β -sheet leads to a strong hydrogel. Interestingly, the disulphide-linked dimer of the PA failed to attain such aggregation pattern. The pH-induced sol–gel–sol transition can be achieved for several cycles without any change in aggregation pattern. The hydrogel was also found to show thixotropic rheological behaviour and thus, it can be utilized as an injectable hydrogel for biomedical applications.

中文翻译：

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pH 值和二级结构指示肽两亲物聚集成触变水凝胶

基于肽-两亲物 (PA) 的超分子触变水凝胶由于具有多种优势特征以及其生物相容性和生物降解性，因此可用于医学科学。在这项工作中，我们从 $$\upbeta $$ β-折叠形成短 PA 开发了一种自组装的基于肽的水凝胶。PA 的水凝胶化受 pH 值和 PA 获得的二级结构的相应变化控制。在酸性条件下，PA 保持无规卷曲构象。在将 pH 值提高到 9 的同时，快速转变为反平行的 $$\upbeta $$ β-折叠会导致强水凝胶。有趣的是，PA 的二硫键连接的二聚体未能达到这种聚集模式。pH 诱导的溶胶-凝胶-溶胶转变可以在几个循环内实现，而聚集模式没有任何变化。