The disclosure provides local delivery of a trace element to a site of tissue injury, which triggers the body' inherent tissue repair mechanism. Local delivery of copper to the site of injury induces migration (i.e., homing) of stem cells to the site of injury, triggers differentiation of stem cells at the site of injury, induces tissue regeneration at the site of injury, induces signaling molecules that trigger tissue regeneration, reverses damage at the site of injury, and / or reconstructs the microenvironment of neurofibril cells and neurosecretory cells at the site of injury. In another aspect, delivering a trace element (for example, copper) directly to the site of injury and associated methods are disclosed.