Self-Assembled Hydrogel from Pyrene-Modified Peptide as 3D Matrices for Neuronal Cell

Self-assembled hydrogels offer biomimetic platforms for three-dimensional (3D) cell culture; yet, achieving stability and functionality under physiological conditions remains a challenge. Here, we report a series of pyrene (Py)-modified peptides designed to form hydrogels with tunable physical and biological properties. Among them, Py-L₃K₃ uniquely formed stable, fluorescent hydrogels at both neutral and basic pH, in contrast to Py-K₆ and Py-A₃K₃, which gelled only at basic pH. Molecular dynamics simulations revealed pH-dependent clustering as a key mechanism driving hydrogel formation. Structural analysis showed that Py-L₃K₃ forms nanofibrillar networks with granular surface morphologies and β-sheet-rich conformations. Rheological studies demonstrated its solid-like viscoelastic behavior and self-healing capability, as determined by oscillatory shear measurements. Importantly, Py-L₃K₃ supported neuronal cell viability, attachment, and growth under physiological conditions, highlighting its potential as a 3D culture scaffold. These findings present Py-L₃K₃ as a promising candidate for applications in neuronal engineering and injectable regenerative biomaterials.