Strategy for Designing Self-Assembling Peptides to Prepare Transparent Nanofiber Hydrogel at Neutral pH

This study examined the formation of nanofiber hydrogels at neutral pH for 16 types of peptides with different net charges, hydrophobicities, and degrees of polymerization. The peptides formed various hydrogels depending on the arrangement of charged amino acids in the antiparallel β-sheet structure. Circular dichroism (CD) measurement, atomic force microscopy (AFM), visible light spectroscopy, and dynamic viscoelasticity measurement showed that the formation of transparent nanofiber hydrogels in peptides requires at least 2 additional positively or negatively charged amino acids per peptide. When designing the amino acid sequence, it is important to consider both the net charge and position of the charged amino acids, and it should be ensured that basic amino acids do not face other basic ones in the antiparallel β-sheet structure. Peptides that had charged amino acids clustered at the center of the nanofiber formed rigid gels

The mechanical stimulation of cells in 3D culture within a self-assembling peptide hydrogel

The aim of this present study was to provide a scaffold as a tool for the investigation of the effect of mechanical stimulation on three-dimensionally cultured cells. For this purpose, we developed an artificial self-assembling peptide (SPG-178) hydrogel scaffold. The structural properties of the SPG-178 peptide were confirmed by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and transmission electron microscopy (TEM). The mechanical properties of the SPG-178 hydrogel were studied using rheology measurements. The SPG-178 peptide was able to form a stable, transparent hydrogel in a neutral pH environment In the SPG-178 hydrogel, mouse skeletal muscle cells proliferated successfully (increased by 12.4 +/- 1.5 times during 8 days of incubation; mean +/- SEM). When the scaffold was statically stretched, a rapid phosphorylation of ERK was observed (increased by 2.8 +/- 0.2 times; mean +/- SEM). These results demonstrated that the developed self-assembling peptide gel is non-cytotoxic and is a suitable tool for the investigation of the effect of mechanical stimulation on three-dimensional cell culture