Controlling Self-Assembling Peptide Hydrogel Properties through Network Topology

Abstract

Self-assembling peptide-based hydrogels have The formation of hydrogels by self-assembling peptides 44 involves two distinct processes; the self-assembly of the 45 peptides themselves to form thin fibrillar structures and the 46 entanglement and association of these fibrils into a threef1 47 dimensional percolated network (Figure 1). Developing a 48 fundamental understanding of these two processes at all length 49 scales is crucial as the properties of the final materials will not 50 only depend on the intrinsic properties of the fibers, but also on In this work we were interested in understanding how 77 network topology affects the mechanical properties of the 78 hydrogel and how it can be used to design materials with 79 tailored properties. For this purpose we decided to use a family 80 of octapeptides based on the same design that are known to 81 self-assemble into β-sheet rich fibrils. This approach allowed us 82 to keep the fiber structure identical across all the systems and 83 focus on the effect of network topology on the mechanical 84 properties of the hydrogels formed. As mentioned above due to 85 the design chosen interfiber interactions are controlled mainly 86 by the hydrophilic residues. Of particular interest to us was 87 arginine, which is a residue that has a guanidine side group. 88 were assessed in an oscillatory mode, using a stress-controlled ) < 2.4, with q = 171 (4π/λ) sin(θ/2), where θ is the scattering angle. The collected data 172 was corrected for the detector efficiency and dark current background. 173 Counter normalization was achieved by using the incoherent scattering 174 of an amorphous hydrogenous poly(methyl methacrylate) secondary 175 standard. After ensuring the scattering was isotropic, the data were 176 radially averaged to obtain a one-dimensional scattering curve. Under 177 these conditions, the normalized intensity scattered by a sample is

Tuning of hydrogel stiffness using a two‐component peptide system for mammalian cell culture

“…This could contribute to the high G′ values of the hydrogels. Instead, in the case of ionic complementary peptides, the fibers present a hydrophilic and hydrophobic face and the aromatic groups are exposed only on one side . Rheological data of the two‐component peptide hydrogel shows a significant increasing of the stiffness, when SA21 peptide is added to the hydrogel.…”

“…Several studies have shown peptide hydrogel systems with tuneable stiffness, where tuning is mainly achieved by varying peptide concentrations in the hydrogels . Some attempts to change hydrogel stiffness by varying amino acid composition in peptide amphiphilic systems has been explored, highlighting the key role of hydrophobic interactions in gel stiffness . A similar effect on gel strength can be obtained by varying salt concentration, when charged amino acids are present in the peptide sequence .…”

Balancing hydrophobicity and sequence pattern to influence self‐assembly of amphipathic peptides

“…As a result, these nanoribbons maintain high solubility in aqueous solvents, making them ideal materials for biological applications. Because of the high utility of this class of amphipathic peptide, they have been widely adopted as models to study the fundamental physicochemical basis of peptide self‐assembly processes in order to facilitate the rational design of next‐generation materials derived from self‐assembled β‐sheet peptides …”

Western Blot Analysis of Cells Encapsulated in Self-Assembling Peptide Hydrogels

“…SDS is an anionic surfactant that acts to both coat hydrophobic regions of proteins with a negative charge and mask positive charges in proteins. In theory, SDS should interact with both the hydrophilic and hydrophobic face of the -sheet-forming FEFKFEFK (F8) peptide (30,31), coating the F8 peptide with a negative charge that upon dissociation of the peptide fibers should hinder their ability to self-assemble (32). Therefore, attempts were made to solubilize the cell-seeded F8 hydrogel through sonication with a detergent-based buffer (RIPA buffer; see above for details) in which the SDS content was varied from 0.1% to 2% with a view to accommodate the abundance of F8 peptide present (Figure 1).…”