De Novo Design of a Shear-Thin Recoverable Peptide-Based Hydrogel Capable of Intrafibrillar Photopolymerization

Abstract

A de novo designed peptide-based gel has been prepared whose mechanical rigidity can be modulated after shear-thin recovery. The photopolymerizable β-hairpin peptide named MLD undergoes temperature-induced folding and self-assembly to afford a network of β-sheet-rich fibrils that constitutes a moderately rigid hydrogel (G 0 = 220 ( 50 Pa, 1 wt %). The MLD hydrogel can be shear-thinned into a lowviscosity gel upon application of shear stress and immediately recovers its mechanical rigidity upon termination of stress. MLD peptides contain non-natural sorbamide derivatives of lysine that allow the mechanical rigidity of its hydrogels to be enhanced through polymerization of dienes displayed along the surface of the fibrils constituting the gel. Irradiation of the gel network increases its mechanical rigidity ∼2.5-fold. Circular dichroism (CD) spectroscopy shows that MLD folds and self-assembles into β-sheet-rich fibrils and that photo-cross-linking does not influence the secondary structure contained within the assembly. The MLD hydrogel shows potential as an injectable material whose mechanical properties can be modulated after delivery.

Chondroinduction from Naturally Derived Cartilage Matrix: A Comparison Between Devitalized and Decellularized Cartilage Encapsulated in Hydrogel Pastes

“…MeHA was then dialyzed against deionized (DI) water for 2 days and then frozen at -80°C and lyophilized. The degree of methacrylation was determined using 1 H NMR (Avance AV-III 500; Bruker) by calculating the ratio of the relative peak area of methacrylate protons to methyl protons. 22 Tissue retrieval, devitalization, and decellularization…”

“…1,2 To overcome this drawback, we recently introduced a method to achieve paste-like hydrogel precursor solutions by combining hyaluronic acid nanoparticles with traditional crosslinked hyaluronic acid hydrogels, where the paste-like behavior was induced by the presence of the hyaluronic acid nanoparticles. 3 These hyaluronic acid formulations were then crosslinked to form a rigid traditional hydrogel structure.…”

Enabling Surgical Placement of Hydrogels Through Achieving Paste-Like Rheological Behavior in Hydrogel Precursor Solutions

“…2, 3, 6 However, hydrogels lack the ability to be molded into a defect site by a surgeon because hydrogel precursors are liquid solutions that are prone to leaking after placement, 19, 22 which confounds their ability to be used by surgeons in the clinic. Therefore, although the main focus of hydrogel technology and developments are on hydrogels in their crosslinked form, our primary focus is on the fluid behavior of hydrogel precursor solutions (i.e., the fluid behavior of the hydrogel prior to crosslinking).…”

Controlling network topology and mechanical properties of co‐assembling peptide hydrogels

“…One example that overcomes this was demonstrated by Rughani et al where they designed a photo-polymerizable beta-hairpin peptide that contained non-natural sorbamide derivatives of lysine. 22 Irradiation of this self-assembled hydrogel induced the polymerization of the dienes present and this increased the mechanical rigidity of the hydrogel 2.5-fold. Although elegant, this method still requires post-treatment after the gelation stage.…”