This document relates to methods and materials for treating nerve injuries. For example, thermoresponsive compositions containing 4-aminopyridine (4-AP) and/or one or more derivatives of 4-AP as well as methods for using such thermoresponsive compositions as a delivery system for 4-AP and/or one or more derivatives of 4-AP (e.g., to treat nerve injury) are provided. This document also provides methods and materials for treating a wound (e.g., a skin wound). For example, compositions containing 4-AP and/or one or more derivatives of 4-AP can be administered (e.g., systemically administered) to a mammal having a wound (e.g., a skin wound) to treat the wound (e.g., to promote wound healing).