Biomimetic Hydrogels from Mixed Gellan Gum and Tryptophan Zipper Self-Assembling Peptides.

Peptide self-assembly has been used to fabricate synthetic hydrogels that emulate many of the chemical and physical properties of natural hydrogels. However, these materials often lack stability for many applications and do not display the native bioactivity found in tissue. Here we demonstrate a hybrid hydrogel system in which self-assembling peptides are integrated with polysaccharides to enhance gelation and provide improved mechanics and bioactivity. A peptide based on the tryptophan zipper (trpzip) motif was mixed with the anionic polysaccharide gellan gum, demonstrating gelation within minutes with increased stiffness compared to that of trpzip alone. The hybrid material maintained viscoelastic character with shear-thinning, self-healing, and stress-relaxation on the order of natural materials like collagen. All hydrogels supported cell adhesion and viability with increased gellan gum content, promoting cell assembly into aggregates. The enhanced gelation kinetics, stability, self-healing, and bioactivity of these materials make them promising candidates as matrices for cell culture and reagents for biofabrication and syringe extrusion for biological delivery.