US scientists have developed a new form of drug that promotes the regeneration of cells and reversed paralysis in mice with spinal injuries, allowing them to walk again within four weeks of treatment. "The therapy is administered as a simple injection into the spinal cord," explains Samuel Stupp, who led the study by a team of Northwestern University scientists. The professor says the team hopes to approach the Food and Drug Administration (FDA) to start human trials as early as next year. IMAGES AND SOUNDBITES