Enzymatically Regulated pH-Responsive Hydrogel with Intrinsic Electromechanical Cue toward Myoblast Differentiation

Microenvironments play a crucial role in guiding cell proliferation and differentiation, yet controlling these factors in soft tissues remains challenging. In native muscle tissue, electrical and mechanical cues orchestrate cell behavior and development. Herein, we exploited Schiff-base chemistry to cross-link peptide nanofiber, 1NF with dopamine ortho-quinone pendants from PDMA through pH-dependent autoxidation to develop a synthetic peptide–polymer conjugated nanofibrous network, 1NF⊂PDMA. Such molecular manipulation led to pH controlled bundled network with enhanced piezoresponse. Using such nanoscale engineering, we demonstrate, for the first time, a synthetic mimic of fibrin with characteristic nonlinear mechanical response with pH-controlled heat and strain stiffening. Furthermore, we show feedback control using two antagonistic enzymes to regulate the pH and in-situ transient stiffening of the hydrogel network. Finally, the intrinsic nonlinear elastic behavior and piezoelectric response of the hydrogel network enhances C2C12 myoblast adhesion, proliferation, and maturation to myotubes, with significantly enhanced expression of the myogenic markers MyoD and MyoG in 48 h, a notable feat achieved for the first time to suggest its future potential toward designing muscle-mimetic synthetic ECM.