The extracellular matrix (ECM) is a vital component of all tissues that contributes to the physical and chemical cues that can affect cell fate. The design of materials to encourage the repair of tissue after injury is a long-standing goal of regenerative medicine. Supramolecular polymers based on reversible noncovalent interactions form fibrous materials that can act as simple but tailored ECM mimics. On page 848 of this issue, Álvarez et al. (1) show that tuning the dynamics of bioactive supramolecular polymers correlates with the degree of regeneration and functional outcome after acute spinal cord injury (SCI) in mice.