Nanomaterials: Application & Properties, 2018 IEEE 8th International Conference on Nanomaterials: Applications & Properties

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Effect of L-Valine Substitution on Self-assembly and Gelation Properties of Fmoc-Phenylalanine-Glycine Dipeptide Nanofibers
Haniyeh Najafi, Samira Abolmaali, Negar Azarpira, Sedigheh Borandeh, Ali Mohammad Tamaddon

Last modified: 2018-09-14

Abstract


Fmoc-dipeptides possess eminent self-assembly features due to the inherent hydrophobicity and aromaticity of the Fmoc moiety which can promote the association of building blocks. Moreover, side-chain charge and their sequence affect the extent of self-assembly and subsequent gelation. This study was aimed to indicate the impact of peptide sequence on self-assembly and gelation of peptides. Herein, Fmoc-phenylalanine-glycine and Fmoc-phenylalanine-valine were synthesized by liquid phase synthesis and characterized by fourier-transform infrared spectroscopy and size exclusion chromatography. To form the dipeptide hydrogels Fmoc-phenylalanine-glycine and Fmoc-phenylalanine-valine were dissolved in deionized water at pH 10, followed by reduction of pH to 7.2 and 5, respectively. The gelation process led to formation of entangled nanofibers as confirmed by vial inversion test and field emission scanning electron microscopy. Based on FE-SEM images, both Fmoc-phe-val and Fmoc-phe-gly formed a fibrous network with fibril diameters ranging from 10 to 100 nm. However, the fibrils of Fmoc-phe-val were not as rigid as Fmoc-phe-gly and showed a “spaghetti-like” characteristics which was more appropriate for biomedical applications.